O-Gastroenterology Flashcards

1
Q

A 27-year-old woman comes to the emergency department because of the recent onset of severe right upper quadrant abdominal pain. She reports a 3-day history of purulent vaginal discharge and pelvic tenderness. She is sexually active and does not use condoms. Physical examination shows mucopurulent cervical discharge and cervical motion tenderness. Which of the following findings is most likely to be specifically associated with this patient’s abdominal pain?

  1. Vaginal Discharge
  2. Increased serum AST and ALT activity
  3. Elevated CRP
  4. Perihepatitis
  5. Endometritis
A

Correct answer: perihepatitis

Major takeaway: Fitz-Hugh-Curtis syndrome refers to perihepatitis in the context of pelvic inflammatory disease and is characterized by inflammation of the liver capsule and adjacent peritoneal structures. Patients typically present with right upper quadrant pain.

Main explanation: The diagnosis of pelvic inflammatory disease (PID) should be considered in any patient with lower abdominal or pelvic pain who is sexually active. Given the potential for permanent reproductive sequelae if treatment is delayed, a high index of suspicion should be maintained. PID can be associated with other findings, including inflammation of the liver capsule. This perihepatitis in the context of PID is known as Fitz-Hugh-Curtis syndrome. Patients present with right upper quadrant pain, which can be associated with a pleuritic pain or referred pain to the right shoulder. Findings on paroscopy or visual examination include “violin string” adhesions, or fibrinous exudateson the surface of the liver.

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2
Q

A 55-year-old man comes to the emergency department because of several episodes of vomiting. The patient complains of retrosternal chest pain, back pain, and shortness of breath. Auscultation shows diminished breath sounds bilaterally at the bases, and a crackling sound heard best directly over the heart. Palpation of the anterior chest is best described as feeling like there are “rice crispies” underneath the skin. Which of the following tests would confirm the diagnosis?

  1. Barium swallow study
  2. Echocardiogram
  3. Endoscopy
  4. Gastrografin swallow study
  5. Upright chest radiograph
A

Answer: Gastrografin swallow study

Not upright chest radiograph because: A chest X-ray is useful in initial workup as it can show various findings such as subcutaneous emphysema, pneumomediastinum , mediastinal widening, and pleural effusion. However, it does not confirm the diagnosis.

Major takeaway: Boerhaave syndrome is characterized by chest and back pain following an episode of strenuous vomiting, with a clinical finding of subcutaneous emphysema . Gastrografin esophagogram is used to confirm the diagnosis.

Main explanation: This patient has Boerhaave syndrome (rupture/perforation of the esophagus due to forceful vomiting). The Mackler triad of vomiting, lower chest pain , and subcutaneous emphysema are classically associated with esophageal rupture but are not always present on initial presentation. Other symptoms and physical findings to look for are back pain, tachycardia , shortness of breath , and Hamman’ sign (crackling sound heard on the chest as the heart beats surrounded by air-filled tissues). The palpation of subcutaneous emphysema (“rice crispies under the skin “) is the most telling sign of an esophageal rupture in a patient with this history. Repeated vomiting creates an increased intraesophageal pressure that can lead to rupture. The perforation then leads to rapid inflammation due to esophageal contents leaking into the mediastinal , pleural , or peritoneal space. Esophagram using Gastrografin is performed to confirm the diagnosis and locate the site of rupture in Boerhaave syndrome . If this is unavailable, or is negative with a high clinical suspicious a CT scan is useful. CT has the additional benefit of being able to identify sites that may be suitable for surgical drainage. This website explains the syndrome and imaging: http://www.learningradiology.com/notes/ginotes/boerhavvepage.htm

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3
Q

A 94-year-old man comes to the office because of a small bulge on the right side of his groin. He first noted the lesion after helping his daughter move to a new home. He reports sharp discomfort that is worsened by walking and heavy lifting. Resting supine decreases the severity of the pain. Physical examination shows a bulge that protrudes medially to the inferior epigastric vessels when the patient coughs. There is no erythema or warmth. Which of the following is the most likely diagnosis?

A Hiatal hernia 
B Strangulated hernia 
C Femoral hernia 
D Direct inguinal hernia 
E Indirect inguinal hernia
A

Answer: Direct inguial hernia

NOT indirect inguinal hernia: Indirect inguinal hernias are considered congenital lesions and result from failure of the processus vaginalis to obliterate, allowing abdominal contents to protrude through the deep inguinal ring. The protrusion occurs lateral to the inferior epigastric vessels .

Major takeaway Direct inguinal hernias result from weakness in the floor of the inguinal canal , leading to protrusion of abdominal contents through Hesselbach’s triangle. This triangle is bounded by the inferior epigastric vessels laterally, the inguinal ligament inferiorly, and the rectus abdominis muscle medially.

Main explanation This patient presents with a visible bulge in the groin region and associated discomfort that is worsened by actions that increase intraabdominal pressure, such as walking or heavy lifting. These symptoms are strongly characteristic of an inguinal hernia . Given the patient’s age and history of recent strenuous activity, a direct inguinal hernia is the most likely cause. Direct inguinal hernias involve protrusion of abdominal contents through Hesselbach’s triangle, which is bounded by the inferior epigastric vessels laterally, the inguinal ligament inferiorly, and the rectus abdominis muscle medially. Contents bulge through the external or superficial inguinal ring only and are covered by the external spermatic fascia . Direct hernia result from weakness in the floor of the inguinal canal and are most commonly seen in older men.

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4
Q

A 32-year-old man comes to the emergency department via emergency medical services because of acute onset of speech difficulties. He denies headache , numbness , tingling, or weakness of any extremities. However, he does describe a tremor of his right hand and new clumsiness. His family reports that the patient has been more aggressive and temperamental recently. Vital signs are normal, and physical examination shows a well-developed male with mask-like facies, slight jaundice and palmar erythema . Eye examination findings are shown below. Which of the following laboratory findings is most likely to be consistent with the etiology of the patient’s symptoms?

A Decreased alanine aminotransferase 
B Decreased ceruloplasmin 
C Elevated creatine kinase 
D Elevated erythrocytes 
E Elevated immunoglobulin G
A

ANSWER: decreased ceruloplasmin

Major takeaway: Wilson disease is an autosomal recessive disorder often manifesting as liver disease and neuropsychiatric symptoms due to tissue accumulation of copper . Kayser-Fleischer rings are a classic finding indicative of total body copper overload.

Main explanation: Wilson disease is an autosomal recessive disorder often manifesting as liver disease and neuropsychiatric symptoms due to tissue accumulation of copper . Patients are often homozygous for mutations of the ATP7B gene, which is necessary to link ceruloplasmin to copper and excrete it into bile . This function is absent in Wilson disease , yet ceruloplasmin is still actively degraded, leading to an excess of copper that accumulates despite compensatory increased excretion. Deposition occurs in liver, brain basal ganglia (leading to movement disorders ), eye ( pathognomonic Kayser-Fleischer rings ), and kidney. Other lab abnormalities commonly seen in Wilson disease include increased liver function tests , decreased albumin , prolonged prothrombin time (PT). Treatment is with a chelating agent such as D-penicillamine .

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5
Q

A 38-year-old woman comes to the emergency department because of severe upper abdominal and chest pain. She has been unwell with suspected food poisoning for the past 24 hours, with frequent and severe vomiting. About 12 hours ago, she began to develop retrosternal chest pain that she describes as “burning” and increasing in severity. Physical examination shows temperature is 39°C (102.2°F), pulse is 115/min, respirations are 30/min, blood pressure is 130/78 mm Hg. Her breathing is shallow due to pain. Lung sounds are clear bilaterally, and cardiac examination shows no murmurs, rubs, or gallops. Chest X-ray shows a small left pleural effusion, small pneumothorax, and a moderate pneumomediastinum. Esophageal rupture is diagnosed and the surgical team contacted. Which of the following best describes a recommended surgical treatment for esophageal rupture?

A Insertion of chest tube
B Esophagectomy and gastrectomy
C Esophageal stenting
D Diverting esophagostomy and gastrostomy
E Thoracotomy for drainage of pleural effusion

A

Answer: Diverting esophagostomy and gastrostomy

Not thoracostomy for drainage of pleural effusion: The pleural effusion can be drained in less invasive ways, including thoracentesis or the placement of a chest tube . There is no need for a thoracotomy for the drainage of the pleural effusion in this patient. Furthermore, this does not treat the root cause of this issue.

Major takeaway: Symptoms of esophageal perforation include chest pain , pleural effusion , fever, and leukocytosis . Treatment with esophagostomy and gastrostomy should be performed immediately after diagnosis, as outcomes for the patient are highly dependent on the speed of diagnosis and treatment.

Main explanation: This woman has Boerhaave syndrome , spontaneous esophageal rupture following a severe episode of vomiting. The majority of cases of esophageal rupture are iatrogenic , often during diagnostic procedures such as endoscopy , and occur in the proximal 1/3 of the esophagus . Spontaneous rupture tends to occur in the distal 1/3 of the esophagus . Characteristics of esophageal perforation include chest pain , pleural effusion on chest x-ray , fever, and leukocytosis . If left untreated, esophageal perforation can lead to sepsis and death. The outcome for a patient is mainly dependent on the speed with which diagnosis and treatment occur, making recognition of this presentation critical. Following diagnosis, the patient should be prepared for surgery through maintenance of the airway , broad-spectrum antibiotic therapy, blood type and crossmatch , and placement of a nasogastric tube with endoscopic guidance. Diverting esophagostomy and gastrostomy is one potential treatment option for this patient, effectively preventing further leakage through the esophageal perforation into the pleural cavities and mediastinum . Later reconstructive surgery is usually indicated to restore the gastric conduit. Other options include repair of the perforated site (when possible), drainage alone, and resection of the site followed by anastomosis (such as esophagectomy).

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6
Q

A 25-year-old man comes to the emergency department because of fever, jaundice, and pain localized to the right upper quadrant. Endoscopic retrograde cholangiopancreatography shows alternating strictures and dilation of the bile ducts with a characteristic “beading” appearance with the involvement of both intrahepatic and extrahepatic bile ducts. Which of the following is the most likely diagnosis?

A Crohn disease 
B Polymyalgia rheumatica 
C Primary biliary cirrhosis 
D Primary sclerosing cholangitis 
E Sarcoidosis
A

Answer: Primary sclerosing cholangitis

Major takeaway: Primary sclerosing cholangitis (PSC) leads to fibrosis in the intra- and extrahepatic bile ducts . The hallmark feature of PSC is a “beading” appearance of the biliary tree in radiographic imaging with contrast. Main explanation Primary sclerosing cholangitis (PSC) is a chronic idiopathic disorder involving inflammation and fibrosis of both intra- and extrahepatic bile ducts . Alternating dilation and stricture of bile ducts result in characteristic “beading” appearance on ERCP. Concentric fibrosis of the bile duct lumen and loss of small bile ducts may be seen in histological section. Up to 70% of patients with PSC suffer from ulcerative colitis . PSC patients are usually male and in their third through fifth decades of life. PSC can be characterized by jaundice , pruritus, and progressive fatigue. Laboratory studies usually show elevated alkaline phosphatase and perinuclear antineutrophilic cytoplasmic antibody ( p-ANCA ). The disease is progressive over many years, and 10-15% of PSC patients go on to develop cholangiocarcinoma . The only effective therapy for PSC is liver transplantation .

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7
Q

A 63-year-old man comes to the office because of heartburn for the past four months. He experiences a burning feeling in his chest whenever he eats. He has also had difficulty swallowing his food. The patient has lost 6.8-kg (15-lb) over the past four months. A chest radiograph is obtained and shown below. Which of the following is the most likely diagnosis?

A. Achalasia - Achalasia is characterized by a increased tone of the lower esophageal sphincter (LES), which makes the sphincter more difficult to relax. It is caused by the absence of inhibitory innervation of the LES, such as in Chagas disease . Progressive dysphagia , regurgitation, and aspiration of undigested food are common features.

B Gastroparesis - Gastroparesis refers to delayed emptying of gastric contents. Many cases of gastroparesis are idiopathic , but it can be caused by diabetes or previous surgery. Gastroparesis is characterized by early satiety , nausea , abdominal pain , bloating , and weight loss.

C Paraesophageal hernia - Paraesophageal hernias (type II, III, and IV) account for 5-10% of hiatus hernias . Paraesophageal hernias are characterized by protrusion of the fundus of the stomach above the diaphragm . Epigastric or substernal pain, postprandial fullness, and nausea are common features.

D Sliding hiatal hernia

E Zenker diverticulum - Zenker diverticulum is an outpouching of the mucosa and submucosa between the cricopharyngeus and lower inferior constrictor muscles. It is characterized by transient dysphagia , pulmonary aspiration , foul breath , and appearance of a neck mass.

A

ANSWER: sliding hiatial hernia

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8
Q

A 58-year-old woman with a long history of alcohol use disorder comes to the office because of diarrhea, general weakness, and a 4.08-kg (9-lb) weight loss over the past 3 months. She has had difficulties driving at night and feels episodic upper abdominal pain not relieved with antacids or proton pump inhibitors. Laboratory studies show: Serum ionized calcium: 3.5 mg/dL Prothrombin time: 30 seconds Partial thromboplastin time 60 seconds Which of the following is the most likely etiology of this patient’s diarrhea?

A Carcinoid tumor 
B Celiac sprue 
C Chronic gastritis 
D Chronic pancreatitis 
E Pancreatic cancer of the head of the pancreas
A

Answer: chronic pancreatitis

Pancreatic cancer involving the head of the pancreas can produce a similar clinical picture; however, one would also expect to see signs of obstructive jaundice and elevated LFTs.

Major takeaway Patients with chronic pancreatitis typically have abdominal pain and pancreatic insufficiency . Pancreatic insufficiency manifests as symptoms of fat malabsorption and pancreatic diabetes . Main explanation The patient’s clinical picture most likely reflects a malabsorption syndrome . Chronic pancreatitis resulting in chronic pancreatic insufficiency is the most likely diagnosis. Chronic inflammation of the pancreas can result in a critical amount of damage to both the endocrine and exocrine functions of the pancreas . Without the exocrine function of the pancreas , dietary lipids cannot be digested and absorbed nor can the fat-soluble vitamins D, A, K, E. Malabsorption of lipids will result in an osmotic steatorrhea . Malabsorption of vitamins D, A, K, E will result in their respective deficiency symptoms. D = hypocalcemia A = night blindness K = prolonged PT/aPTT E = neurologic deficits and ataxia , though this is very uncommon.

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9
Q

A 22-year-old Jewish woman comes to the emergency department because of severe right lower quadrant abdominal pain for the past two hours. She has had diarrhea and weight loss for several weeks. A colonoscopy is performed, and an image from the procedure is shown below. Which of the following is the most likely complication of this patient’s diagnosis?

A Dehydration 
B Perforation of the appendix 
C Perianal fistulas 
D Right ovarian necrosis 
E Toxic megacolon
A

Answer: Perianal fistulas

Major takeaway Crohn disease leads to fistulas as a common clinical manifestation and complication. Since the bowel inflammation is transmural, sinus tracts penetrate the intestinal wall and give rise to these fistulas .

Main explanation Based on her symptoms of intermittent diarrhea, weight loss, and abdominal pain , as well as the results of endoscopy , the patient likely has Crohn disease . Notably in the clinical description, this patient’s right lower quadrant pain is typical, since the terminal ileum is often affected. Malabsorption of nutrients is common in Crohn, hence her weight loss. Granulomatous skip lesions may be seen on endoscopy . Histologically, Crohn disease is characterized by transmural intestinal inflammation and cobblestone mucosa. Crohn disease can affect anywhere in the GI tract (“mouth to anus “), so aphthous ulcers can be seen in the mouth, and even the esophagus can be affected, though rarely. Complications of Crohn disease include fistulas . Sinus tracts that penetrate the serosa give rise to fistulas , which are usually indolent rather than presenting as an acute abdomen . Up to 45% of patients develop a fistula before a diagnosis of Crohn disease . The fistulas mostly occur in the perianal region, but they can also form between the intestine and bladder / uterus .

RE OTHER OPTIONS:

  • Dehydration would most likely occur secondary to severe diarrhea caused by a bacterial infection. Yersinia , Campylobacter , or Salmonella enterocolitis may mimic appendicitis , but the presentation for these infections would be more acute.
  • Perforation of the appendix is a complication of appendicitis . This would have a more acute presentation without the weeklong symptoms of diarrhea and weight loss. The endoscopic image does not suggest appendicitis .
  • Ovarian torsion that results in blockage of blood supply to the ovary may lead to necrosis of the ovary . Patients are characterized by acute, moderate to severe pelvic pain with nausea and vomiting. An adnexal mass may be palpable.
  • Toxic megacolon is a potentially lethal complication of inflammatory bowel disease , but it is more commonly seen in patients with ulcerative colitis . Patients are characterized by >10 stools/day, bleeding, abdominal pain , distension , and acute, severe toxic symptoms.
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10
Q

A 43-year-old man with a recurrent fistula-in-ano comes to the office for monitoring of his Crohn disease. An MRI is done to determine whether he has developed a complex, multi-tract fistula. The MRI shows that his fistula only follows one tract. It courses perpendicularly to the skin from its external perianal opening, then takes a sharp 90° turn and burrows through both the external anal sphincter and the internal sphincter to open into the anal canal. According to the Parks classification of fistulas, which of the following most accurately describes this patient’s fistula-in-ano?

A Extra-sphinteric fistula 
B Inter-sphincteric fistula 
C Supra-levator fistula 
D Supra-sphincteric fistula 
E Trans-sphinteric fistula
A

Major takeaway Trans -sphincteric fistulas are often the result of ischiorectal fossa abscesses and account for 25% of all anal fistulas . They commonly start at the dentate line and then course through the internal and external anal sphincters into the ischiorectal fossa, opening onto the perianal or perineal skin .

Main explanation A perianal fistula ( fistula-in-ano ) is a chronic fistulous tract between the anal canal and the perianal skin . They usually originate from the anal glands, which are located between the internal and external anal sphincter , and drain into the anal canal . If these glands become blocked, abscesses can form and eventually lead to fistula formation. The Parks classification is a widely used method for distinguishing four types of fistula . In order of decreasing frequency, they are: Inter-sphincteric Trans -sphincteric Supra-sphincteric Extra-sphincteric Fistula formation is a complication of Crohn disease , in which there is transmural inflammation of the intestinal wall . Trans -sphincteric fistulas result from abscesses in the ischiorectal fossa. This type accounts for 25% of anal fistulas . They begin at the dentate line and then course through the internal and external anal sphincters into the ischiorectal fossa, and open onto the perianal or perineal skin . The patient’s MRI finding corresponds to this type of fistula . Management of enterocutaneous fistulas begins with treatment of the abscess . Approximately one-third closes spontaneously within 5-6 weeks with conservative management. Surgical closure is necessary if this is not adequate.

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11
Q

A 70-year-old woman comes to the emergency department because of blood in her stool. She says that her stool has been black and tarry, but she can occasionally see red streaking. She reports no recent weight loss or abdominal pain. Her past medical history is significant for Hepatitis C infection. Stool guaiac cards are positive. Endoscopy shows long, red streaky areas on the stomach. Which of the following is the most likely diagnosis?

A Ménétrier disease 
B Dieulafoy lesion 
C Gastric antral vascular ectasia
D Peptic ulcer disease 
E Stomach cancer
A

Answer: gastric antral vascular ectasia

Major takeaway Gastric antral vascular ectasia is an uncommon cause of gastrointestinal bleeding or iron deficiency anemia . It is associated with dilated small blood vessels in the antrum of the stomach. The dilated vessels result in the bleeding. Gastric antral vascular ectasia gives the appearance of a “ watermelon stomach .”

Main explanation Gastric antral vascular ectasia is an uncommon cause of gastrointestinal bleeding or iron deficiency anemia . It is associated with dilated small blood vessels in the antrum of the stomach. The dilated vessels result in the bleeding. Gastric antral vascular ectasia gives the appearance of a “ watermelon stomach .” Associated conditions include portal hypertension , chronic kidney failure , and collagen vascular diseases. Diagnosis is typically made by endoscopy which shows characteristic watermelon stripes. Surgical exploration of the abdomen may be needed to diagnose cases with liver or other organ involvement. Treatment often includes argon plasma coagulation and electrocautery . Endoscopy with thermal ablation is the favored medical treatment because of its low side effects and low mortality, but it is rarely curative. The typical patient is an elderly woman, and about 31% of patients have portal hypertension .

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12
Q

A 39-year-old male comes to the emergency department because of altered mental status, ataxia, and diplopia. His past medical history is only significant for Crohn disease, which he controls with medication. An MRI of his brain is obtained and shown below. Which of the following medications would most likely be responsible for his current neurological symptoms? (it appears like white in the cerebral matter)

A Infliximab 
B Golimumab 
C Natalizumab 
D Cetuximab 
E Alemtuzumab
A

Answer: Natalizumab

Major takeaway Progressive multifocal leukoencephalopathy only occurs in majorly immunocompromised individuals, such as those receiving natalizumab for Crohn disease . It is caused by the John Cunningham (JC) virus and typically presents with hyperintensive lesions on T2 MRI, as well as signs of progressive neurological damage.

Main explanation The patient has progressive multifocal leukoencephalopathy (PML), which is a demyelinating disease of the brain that is common in severely immunocompromised patients. It is caused by the John Cunningham virus. On T2 MRI there are significant hyperintensities and symmetric or asymmetric multifocal areas of white matter demyelination . They do not conform to cerebrovascular territories and exhibit neither mass effect nor contrast enhancement. Natalizumab is a humanized monoclonal antibody and alpha 4 integrin inhibitor that increases a patient’s risk of developing PML if they are already infected with JC virus . Risk factors for the development of PML include duration of therapy, prior use of immunosuppressants , and presence of anti– JC virus (JCV) antibodies. Treatment for patients with natalizumab -associated PML is discontinuation of natalizumab and beginning plasma exchange .

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13
Q

A 26-year-old woman, who is at 30 weeks gestation , comes to a dermatology clinic because of “itchy skin.” The patient states that the itching began over the past two weeks. She has not noticed any skin lesions but has been picking at and scratching her skin with her nails. Physical examination shows faint red and pink excoriations, but no primary skin lesions. A disorder involving which of the following organs is most likely responsible for her skin condition?

A Thyroid
B Thymus
C Uterus
D Liver
E Pancreas
A

ANSWER: Liver

Major takeaway Intrahepatic cholestasis of pregnancy is a reversible form of cholestasis affecting some pregnant women in their second or third trimesters characterized by hepatic dysfunction and pruritus of the skin caused by elevated bile acids in the bloodstream, causing bile salt deposition in the skin, and secondary skin lesions due to scratching only (no primary lesions).

Main explanation Pruritus gravidarum is also known as intrahepatic cholestasis of pregnancy . It is a reversible form of cholestasis affecting some pregnant women in their second or third trimesters. It is believed to be linked to female sex hormone changes that take place in the body during pregnancy and, in some cases, patients who are not pregnant but who are taking oral contraceptive pills . The hallmark of this condition is pruritus of the skin caused by elevated bile acids in the bloodstream, which lead to bile salt deposition in the skin, and secondary skin lesions due to scratching only (no primary lesions). Jaundice may develop with cases of severe cholestasis . The diagnosis of pruritus gravidarum/ intrahepatic cholestasis of pregnancy is confirmed by the laboratory finding of serum bile acids of greater than 11.0 μ mol /L. Pruritus and excoriations of the skin should lessen with treatment and disappear after the patient gives birth. Patients should be advised to avoid picking at their skin to avoid scarring and/or secondary infections.

OTHER EXPLANATIONS: A Thymus Show explanation 2% The thymus is a primary lymphoid organ of immune tissue. It does play a roll in hypersensitivity reactions , but pruritus gravidarum is not caused by thymic dysfunction. B Thyroid Show explanation 4% Pruritus may be seen in cases of hyperthyroidism , but other symptoms of hyperthyroidism are absent in this patient ( flushing , heat intolerance, weight loss, anxiety , etc.). C Uterus Show explanation 1% Pruritus is often associated with pregnancy, most often due to changes in the skin, especially that of the abdomen . Pruritus gravidarum is not caused by uterine dysfunction. D Liver Show explanation 86% E Pancreas Show explanation 7% Carcinoma of the pancreas rarely has ben associated with generalized pruritus. It has been known to be an important symptom in other malignancies.

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14
Q

A 33 year-old man comes to the gastroenterologist because of progressive dysphagia over the last 3 months. Barium swallow shows a dilated esophagus with an area of distal stenosis. Upon surgical treatment of the patient’s condition, which of the following is the patient at the greatest risk of developing?

A Gastric carcinoma 
B Gastro-esophageal reflux disease 
C Mallory-Weiss syndrome 
D Plummer-Vinson syndrome 
E Zollinger-Ellison syndrome
A

ANSWER: GERD

Major takeaway The treatment of achalasia is surgical myotomy or pneumatic dilation of the esophagus to relax lower sphincter tone . This can lead to over-relaxation and gastroesophageal reflux disease .

Main explanation This patient has achalasia , which results from failure of relaxation of lower esophageal sphincter (LES) due to the loss of the myenteric (Auerbach’s) plexus. The progressive dysphagia is caused by the stenotic LES. Treatment of achalasia includes pneumatic dilation of the LES or surgical myotomy. Because the treatment involves relaxing the LES, the patient can be more prone to gastroesophageal reflux disease . Primary achalasia is an idiopathic loss of myenteric ganglion cells that leads to dysregulated constriction of the LES. Secondary achalasia is caused by a known insult, such as Trypanosoma cruzi in Chagas disease . Symptoms of achalasia include progressive dysphagia to solids and liquids, putrid breath , and regurgitation.

OTHER EXPLANATIONS: Gastric carcinoma Show explanation 16% Gastric carcinoma may result from disruption of the gastric mucosa from chronic gastritis . Treatment of achalasia doesn’t influence such processes. B Gastro-esophageal reflux disease Show explanation 63% C Mallory-Weiss syndrome Show explanation 9% Mallory-Weiss tears at the gastroesophageal junction are caused by excessive vomiting or retching. The treatment of achalasia does not predispose the patient to either one. D Plummer-Vinson syndrome Show explanation 8% Plummer-Vinson syndrome (PVS) is a long-term iron deficiency anemia resulting from esophageal webs in the proximal esophagus (near the upper esophageal sphincter ). Achalasia is not associated with PVS. E Zollinger-Ellison syndrome Show explanation 4% Zollinger-Ellison syndrome is caused by a gastrin -secreting tumor of the pancreas that stimulates the acid-secreting cells of the stomach ( parietal cells ) to maximal activity, with consequent gastrointestinal mucosal ulceration. It is not associated with achalasia.

KNOWLEDGE POINTS:

Stomach cancer is most commonly gastric adenocarcinoma developing from the lining of the stomach. The most common cause is infection by the bacterium Helicobacter pylori, which accounts for more than 60% of cases. Other causes include dietary nitrosamines (smoked foods), tobacco smoking, achlorhydria, and chronic gastritis. This cancer often presents late, with weight loss, early satiety, and in some cases acanthosis nigricans or Leser-Trélat sign.

Achalasia is a failure of relaxation of the lower esophageal sphincter due to loss of the myenteric (Auerbach) plexus. This can lead to progressive dysphagia to solids and liquids. A barium swallow will show a dilated esophagus with an area of distal stenosis. This is also the characteristic ‘bird’s beak’ sign.

Mallory–Weiss syndrome or gastro-esophageal laceration syndrome refers to bleeding from a laceration in the mucosa at the junction of the stomach and esophagus. This is usually caused by severe vomiting because of alcoholism or bulimia, but can be caused by any conditions which causes violent vomiting and retching such as food poisoning. The syndrome presents with painful hematemesis. The laceration is sometimes referred to as a Mallory-Weiss tear.

The triad of iron deficiency anemia, dysphagia, and a cervical esophageal web is known as Plummer-Vinson or Paterson-Brown-Kelly syndrome. Treatment with iron supplementation and mechanical widening of the esophagus generally provides an excellent outcome. Nowadays, this syndrome has become extremely rare.

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15
Q

A 30-year-old woman comes to the clinic because of fever and fatigue. She has no chest pain, cough, sore throat, or hemoptysis. She works as a nurse practitioner in a nearby hospital. Five months ago, she was injured by a needle from a hepatitis patient. She also has Hashimoto’s thyroiditis and receives replacement therapy. Her temperature is 38.5°C (101.3°F), pulse is 100/min, respirations are 15/min, and blood pressure is 110/70 mm Hg. Physical examination shows jaundice and right upper abdominal quadrant tenderness. Laboratory studies show:

See photo for question 15

Which of the following is the most likely diagnosis?

A Primary biliary cholangitis B Acute hepatitis C infection C Chronic hepatitis B infection D Autoimmune hepatitis E Acute hepatitis B infection

A

ANSWER: Auto-immune hepatitis

Major takeaway Autoimmune hepatitis is an immune mediated injury of the liver cells . It is caused by aberrant HLA class II. It may present as acute hepatitis , chronic hepatitis , or cirrhosis . Antismooth muscle antibody (SMA) is very specific for autoimmune hepatitis .

Main explanation Autoimmune hepatitis is an immune mediated hepatic injury . It is due to aberrant human leukocyte antigen (HLA) class II on liver cells . The aberrant HLA II induces the immune system to attack the liver causing autoimmune hepatitis . The cause of aberrant HLA is still unknown. Autoimmune hepatitis usually occurs in women between the ages of 15 and 40. It may present as acute hepatitis , chronic hepatitis , or cirrhosis . Around one third of the patients present with symptoms of acute hepatitis which is characterized by fever, fatigue, jaundice , and upper abdominal quadrant pain. Patients with autoimmune hepatitis usually have other autoimmune diseases like Hashimoto’s thyroiditis in this patient. Laboratory studies in autoimmune hepatitis show elevated liver enzymes (ALT and AST) and positive antismooth muscle antibody (SMA), antinuclear antibody (ANA), liver/kidney microsomal antibodies (LKM), and antibodies to soluble liver antigen (anti-SLA). Antismooth muscle antibody is most specific test for autoimmune hepatitis .

Other explanations: A Primary biliary cholangitis Show explanation 10% Primary biliary cholangitis ( primary biliary cirrhosis ) is an autoimmune destruction of bile ducts that finally leads to biliary cirrhosis . It is characterized by fatigue, pruritus, and right upper quadrant discomfort . Liver enzymes are high, especially ALP and GGT indicating biliary stasis. Antimitochondrial antibody is very specific for this disease. B Acute hepatitis C infection Show explanation 3% The majority of acute hepatitis C infections are asymptomatic. When symptomatic, it has the same symptoms like that mentioned in acute hepatitis B . Laboratory abnormalities in acute hepatitis C include high liver enzymes , positive HCVRNA , and anti-HCV antibody which takes several months to be positive after the primary infection. C Chronic hepatitis B infection Show explanation 8% Chronic hepatitis B patients may be asymptomatic. During replicative state, patients may have fatigue, anorexia, nausea , or upper abdominal pain . Laboratory studies show low albumin , prolonged prothrombin time , high ALT, AST, and bilirubin . In chronic hepatitis B , HBsAg and anti-HBc are positive while anti-HBs are negative. D Autoimmune hepatitis Show explanation 70% E Acute hepatitis B infection Show explanation 9% The majority of acute hepatitis B infections are asymptomatic. When symptomatic, it is characterized by anorexia, nausea , vomiting, fever, jaundice , and right upper abdominal quadrant pain. Abnormal laboratory results include high liver enzymes , positive HBsAg , anti-HBc IgM antibody, and Hepatitis B -e antigen (anti-HBe). Positive anti-HBs only indicates previous immunization .

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16
Q

A 65-year-old man comes to the emergency department because of blood in his stools for the last few days. He denies fever, chills, nausea, or vomiting, and also says that his bleeding is painless. His last colonoscopy was five years ago and only showed several colonic diverticula, but no colonic polyps or cancer. His temperature is 37.0°C (98.6°F), pulse is 80/min, respirations are 15/min, and blood pressure is 120/80 mm Hg. Rectal examination does not show any abnormalities. Leukocyte count is 5,000/mm3. Barium swallow is performed and is shown below. Which of the following is the most likely diagnosis?

See image for gastroenterology 0016

A Colonic diverticulitis 
B Colonic diverticulosis 
C Colonic polyps 
D Crohn disease 
E Ulcerative colitis
A

ANSWER: Colonic diverticulosis

Major takeaway Colonic diverticulosis is an outpouching of the colonic mucosa and submucosa that arises from an unclear etiology. Patients are often asymptomatic; however, a small fraction of patients with diverticulosis develop symptoms. Bleeding alone can sometimes be the only sign of diverticulosis .

Main explanation Colonic diverticulosis is an outpouching of the colonic mucosa and submucosa that arises from an unclear etiology. This condition is common in older patients and more common in the sigmoid colon . Interestingly, there is more right sided diverticulosis in Asian populations. Patients are often asymptomatic; however, a small fraction of patients with diverticulosis develop symptoms. Common symptoms include abdominal pain , bloating , altered bowel habits, or flatulence . Bleeding alone can sometimes be the only sign of diverticulosis . Diverticulosis is often found incidentally during a routine colonoscopy , but they can be found through various imaging modalities including abdominal X-rays , CT, barium enema, and colonoscopy . Plain abdominal X-ray may show signs of bowel wall thickening . Barium enema will show out-pouching of the colonic wall, but it is important to rule out colonic diverticulitis before performing a barium swallow or colonoscopy because the chances of barium leakage or colonic perforation is increased with diverticulitis .

OTHER EXPLANATION: A Colonic diverticulitis Show explanation 21% Colonic diverticulitis can arise from the patient’s history of diverticulosis ; however, this diagnosis is unlikely because he is afebrile, does not have abdominal pain , and has a normal leukocyte count . Also, diverticulitis is not associated with lower GI bleeding . B Colonic diverticulosis Show explanation 70% C Colonic polyps Show explanation 6% Colonic polyps may be a tempting initial choice, but the patient does not have a history of polyps and on barium swallow polyps would be represented by areas absent of barium . D Crohn disease Show explanation 1% Crohn disease is associated with multiple areas of ulceration and inflammation on barium study. Distention of small bowel with contrast material is required for proper evaluation of Crohn disease with barium swallow . E Ulcerative colitis Show explanation 2% Ulcerative colitis is associated with a “lead pipe colon “ and a loss of haustral markings on barium study. Mucosal inflammation leads to a granular appearance on the surface of the bowel .

17
Q

A 45-year-old man comes to the emergency department because of severe upper abdominal pain that began suddenly and has intensified over the past six hours. The patient says that the pain is constant and scores it as a 9 on a 10-point scale. He complains of nausea but has not vomited. The patient says that the pain radiates to his back and is somewhat relieved by sitting up and bending forward. He has a history of gallstones. Physical examination shows epigastric tenderness and reduced bowel sounds. Which of the following is the most appropriate next step for this patient?

A Abdominal CT
B Admission to the ICU
C Aggressive fluid resuscitation, nil orally, and analgesia
D Endoscopic retrograde cholangiopancreatography
E Immediate cholecystectomy

A

Answer: C Aggressive fluid resuscitation, nil orally, and analgesia
NOTE: This is acute pancreatitis

Major takeaway Acute pancreatitis is a disease that can be associated with significant morbidity and mortality. Regardless of the severity, supportive therapy is the initial management step in all cases of acute pancreatitis .

Main explanation Acute pancreatitis , or inflammation of the pancreas , is most commonly caused by gallstones or alcohol use. There are three hallmark features, two of which must be present for the diagnosis of acute pancreatitis : (1) sudden onset of severe abdominal pain , (2) elevation of serum lipase (or amylase ) concentrations to >3 times the upper limit of normal, (3) characteristic findings on ultrasound or CT. While measuring levels of pancreatic enzymes is useful for the initial diagnosis, serial measurements are not useful predictors for following disease progression and predicting prognosis. Acute pancreatitis carries with it significant morbidity and mortality, and as such, must be treated carefully. The first step is to stratify as mild, moderate, or severe based on the absence of organ failure , transient organ failure , or persistent organ failure , respectively. Ranson, The Acute Physiology and Chronic Health Evaluation (APACHE) II, and CT severity index (CTSI) or Balthazar scores are useful tools. Regardless of severity, therapy begins with bowel rest, aggressive IV fluids , and analgesia . Mild disease generally resolves spontaneously with supportive therapy. When the diagnosis of gallstone pancreatitis has been established, cholecystectomy is indicated.

OTHER EXPLANATIONS: A Abdominal CT Show explanation 32% Unless there is a diagnostic uncertainty, abdominal CT scan within 48-72 hours of symptom onset has not been shown to improve patient outcome. The scan may not accurately assess pancreatic changes, such as necrosis, and is indicated after 72 hours if the patient’s condition has not improved. B Admission to the ICU Show explanation 2% Admission to the ICU is indicated in patients with severe acute pancreatitis characterized by hemodynamic instability or severe electrolyte abnormality, or those with a cardiac history which means they may respond poorly to fluid resuscitation . C Aggressive fluid resuscitation , nil orally, and analgesia Show explanation 49% D Endoscopic retrograde cholangiopancreatography Show explanation 14% Endoscopic retrograde cholangiopancreatography (ERCP) should be performed in patients who have signs or symptoms of acute cholangitis . Nil orally, fluid resuscitation , and pain control are the initial steps of treatment in the management of acute pancreatitis . E Immediate cholecystectomy Show explanation 3% Cholecystectomy is recommended during the initial admission for all patients with gallstone pancreatitis . In those with mild disease cholecystectomy within 48 hours is indicated. For those with more severe disease, endoscopic retrograde cholangiopancreatography may be indicated first.

18
Q

A 49 year-old woman comes to the clinic because of tightening of the skin on her hands and face. She has a history of hypertension and asthma. She is currently taking amlodipine, losartan, and salbutamol. She does not smoke or drink alcohol. Her temperature is 37.5°C (99.5°F), pulse is 70/min, respirations are 14/min, and blood pressure is 145/87mmHg. Physical examination shows non-pitting edema and some ulceration on her hands. Her abdomen is not distended. Bowel sounds are hypoactive. She does not have stridor but there is some diffuse bilateral wheezing on auscultation with good air entry bilaterally. Cardiac examination is normal. Which of the following organs is most likely to be affected by the patients disease?

A Esophagus 
B Heart 
C Liver 
D Spinal cord 
E Spleen
A

ANSWER: Esophagus

Major takeaway Systemic sclerosis (scleroderma) is a non-inflammatory autoimmune disorder characterized by widespread small vessel vasculopathy and fibrosis . Systemic sclerosis can affect much of the GI tract, with the esophagus being the most common portion affected, frequently resulting in dysphagia .

Main explanation The patient is suffering from localized system sclerosis, or scleroderma . Systemic sclerosis is a non-inflammatory autoimmune disorder characterized by widespread small vessel vasculopathy and fibrosis .This process leads to atrophy and fibrosis of tissues. Intimal proliferation and degeneration of vessel media leads to progressive obliteration of vessel lumen. Patients often develop hypertension as evident in this patient. Limited scleroderma affects the skin of the face, hands, and neck. The skin on other areas of the body is not affected. Systemic sclerosis can affect much of the GI tract, with the esophagus being the most common portion affected, frequently resulting in dysphagia . Findings on lung exam may represent an early finding of interstitial pulmonary fibrosis , a complication of systemic sclerosis that can be fatal. It affects women more commonly than men and often develops in patients between the age of 40-50. An anti-neutrophil cytoplasmic antibody (ANCA) should be done to aid in the diagnosis. The anti-centromere antibody is positive in patients with limited system sclerosis. Treatment varies depending on the symptoms that the patient is exhibiting.

Other Explanation: A Esophagus Show explanation 67% B Heart Show explanation 16% The clinical symptoms that this patient has is consistent with a diagnosis of scleroderma . The heart is not an organ that is commonly affected by systemic sclerosis . C Liver Show explanation 11% The liver is an organ that is not commonly affected in patients suffering from systemic sclerosis . Other organs in the gastrointestinal system are often affected. D Spinal cord Show explanation 3% The spinal cord is another example of an area of the body that is not commonly affected in patients with systemic sclerosis . E Spleen Show explanation 3% Systemic sclerosis does not affect the spleen . The gastrointestinal tract , lungs, and kidneys are most commonly affected in patients suffering from systemic sclerosis .

19
Q

A 45-year-old woman is brought to the emergency department because of upper abdominal pain. She has nausea, vomiting, and anorexia. Medical history is contributory for gallstones. Patient’s BMI is 39 kg/m2. Her temperature is 38°C (100.4°F), pulse is 107/min, respirations are 31/min, and blood pressure is 85/65 mm Hg. Physical examination shows an ecchymotic discoloration over the flanks. Alkaline phosphatase and serum lipase are both elevated. Which of the following is most likely an associated complication of this patient’s condition?

A Acute respiratory distress syndrome 
B Cardiac contusion 
C Fat embolism 
D Hemothorax 
E Tension pneumothorax
A

ANSWER: ARDS (complication of pancreatitis)

Major takeaway Acute respiratory distress syndrome (ARDS), pseudocyst formation, abscess formation, hypocalcemia , and acute renal failure are all sequelae of acute pancreatitis .

Main explanation Acute pancreatitis is secondary to gallstone disease . Known risk factors for gallstone disease , such as cholelithiasis , are female gender, obesity , and middle age. Gallstone -induced obstruction is also suggested by the elevated levels of alkaline phosphatase and lipase . Grey -Turner and Cullen sign suggest intraperitoneal hemorrhage, which is a complication of acute pancreatitis . Complications of acute pancreatitis also include acute respiratory distress syndrome (ARDS), pseudocyst formation, abscess formation, hypocalcemia , and acute renal failure . ARDS is a medical condition that occurs in critically ill patients and is characterized by widespread inflammation in the lungs. Is triggered by trauma, pneumonia , or sepsis . Diffuse injury to cells (which form the alveolar barrier), surfactant dysfunction, activation of the innate immune response , and abnormal coagulation occur. This results in impaired gas exchange within the lungs at the level of the microscopic alveoli . ARDS is characterized by dyspnea , tachypnea, and low oxygen level in blood. A chest x-ray shows generalized infiltrates in both lungs and diagnosis is made using the Berlin criteria. Treatment is with mechanical ventilation and antibiotic therapy (administered as soon as microbiological culture results are available). The origin of infection, when surgically treatable, is operated on. When sepsis is diagnosed, appropriate local protocols are enacted.

OTHER EXPLANATION: A Acute respiratory distress syndrome Show explanation 70% B Cardiac contusion Show explanation 3% A cardiac contusion is suspected in cases of sternal fracture, with reported pain or tenderness over the mid-anterior chest. An ECG is needed and findings of dysrhythmia , new bundle branch block, or persistent tachycardia are suggestive for contusion . C Fat embolism Show explanation 17% Fat emboli may produce a picture of acute respiratory distress syndrome , however, they are associated with multiple trauma, especially long bone fractures. Other symptoms include a petechial rash in the axillae and neck. D Hemothorax Show explanation 8% Hemothorax is a type of pleural effusion in which blood accumulates in the pleural cavity . This excess fluid interfere with normal breathing by limiting the expansion of the lungs. Hemothorax is characterized by chest pain , dyspnea , and tachypnea. E Tension pneumothorax Show explanation 3% Diagnosis of tension pneumothorax is made from physical examination alone and is characterized by circulatory compromise ( hypotension and increased JVP, among others), tracheal deviation, and decreased breath sounds or hyperresonance to percussion on one side of the chest, in addition to respiratory distress .

20
Q

A 35-year-old woman comes to the emergency department because of progressively worsening right upper abdominal pain for two days. The patients states that for the past 3 months she’s had a similar pain 1-2 hours after meals, but now the pain is more severe and constant. She admits to fever, dark-colored urine, and clay-colored stools. She denies pain radiation, nausea, or vomiting. Physical examination shows a middle aged female in moderate distress with mild jaundice. Abdominal examination shows tenderness to palpation in the upper right quadrant.
A pregnancy test is negative. A complete blood count shows leukocytosis and elevated alkaline phosphatase. Blood culture is positive for Escherichia coli. Based on the patient’s presentation, which of the following is the most likely diagnosis?

A Acute cholecystitis 
B Ascending cholangitis 
C Biliary colic 
D Choledocholithiasis 
E Chronic pancreatitis
A

Answer: Ascending cholangitis

Major takeaway Ascending cholangitis (also called acute cholangitis ) is an ascending bacterial infection of the biliary tract thought to be related to choledocholithiasis and bile stasis. It is characterized by Charcot’s triad of upper right quadrant pain, fever, and jaundice .

Main explanation The patient in this question most likely has ascending cholangitis as evidenced by Charcot’s triad of right upper quadrant pain, fever, and jaundice . Ascending cholangitis (also called acute cholangitis ) is an ascending bacterial infection of the biliary tract thought to be related to choledocholithiasis and bile stasis. If left untreated, this condition has high potential for morbidity and mortality. Typically, patients may have a history of choledocholithiasis or recent biliary tract manipulation. In a more severe form of the disease, septic shock and mental confusion can also be present and these symptoms together with Charcot’s triad are called Reynolds pentad. Physical examination findings include jaundice , icterus , fever, and abdominal pain . Laboratory tests typically show leukocytosis , hyperbilirubinemia , elevated alkaline phosphatase , elevated transaminase and serum amylase , and blood cultures are positive in almost 50% of patients. The top isolated microorganisms include E. coli , Klebsiella , Enterococcus spp, and Bacteroides fragilis . Once diagnosed, administration of broad-spectrum intravenous antibiotics and correction of fluid and electrolyte imbalances are the recommended treatments.

OTHER EXPLANATIONS: A Acute cholecystitis Show explanation 12% History and physical findings that point to acute cholecystitis include pain that radiates to the scapula , nausea , vomiting, fever, history of gallstones , tachycardia , tenderness in the upper right quadrant with guarding or rebound . B Ascending cholangitis Show explanation 73% C Biliary colic Show explanation 3% Biliary colic describes pain that occurs due to a gallstone temporarily blocking the bile duct . The pain can last for a few hours but typically subsides. D Choledocholithiasis Show explanation 10% Choledocholithiasis refers to a stone in the common bile duct . It can cause jaundice and liver damage , but does not typically present with fever. E Chronic pancreatitis Show explanation 1% Chronic pancreatitis often presents with abdominal pain that can radiate to the back and can occur after or independently of meals.

21
Q

A 26-year-old man, Cuban immigrant comes to the office for an evaluation of diarrhea. For the past 2 weeks, he has had bulky, pale, and foul-smelling stools. Medical history is relevant for a recent gastroenteritis a few weeks ago. Upon further questioning, the patient mentions that he has malodorous flatulence and intense bloating after any meal. Physical examination shows abdominal distention and discomfort on palpation. His temperature is 36.1°C (96.9°F), pulse is 60/min, respirations are 17/min, and blood pressure is 116/70 mmHg. Which of the following processes is most likely to occur in this patient as a result of the disease?

A Dermatitis herpetiformis 
B IgA deficiency 
C Reactive arthritis 
D Hypoproteinemia 
E Megaloblastic anemia
A

ANSWER: Megaloblastic Anemia

Major takeaway Megaloblastic anemia due to folate or B12 deficiency is a common finding among patients with tropical sprue . Patients classically have a history of recent travel to a tropical area and present with indigestion , cramps within 2 or 3 weeks after an acute enteric infection.

Main explanation Tropical sprue (or postinfectious sprue ) is a type of malabsorption syndrome characterized by abnormal flattening of the villi and inflammation of the lining of the small intestine due to a previous diarrheal enteric infection. Tropical sprue is usually more common among patients that have a recent travel history to a tropical area (i.e., Caribbean countries, Central and South America ). Patients classically present with malabsorption syndrome (i.e., steatorrhea , indigestion , cramps ) within 1 or 2 weeks after an acute enteric infection. The pathogenesis of tropical sprue is not fully understood. However, the development of the disease is characterized by decreased absorption affecting duodenum and jejunum . This condition varies significantly from celiac sprue , the underlying difference is that tropical sprue responds to antibiotics. On gross pathology, there is a variable villous atrophy (similar to celiac sprue ). Tropical sprue is associated with megaloblastic anemia due to folate or B12 deficiency . The main treatment for tropical sprue is broad-spectrum antibiotics (i.e., tetracycline ) and vitamin supplementation (i.e., folic acid , vitamin B12 ). Unlike patients with celiac sprue , there is no increased risk for intestinal lymphoma .

OTHER EXPLANATIONS: A Dermatitis herpetiformis Show explanation 27% Dermatitis herpetiformis is a type of autoimmune disorder characterized by the formation of skin blisters . This condition is associated with a gluten-sensitive enteropathy . However, patients with tropical sprue (i.e., Cuban immigrant + history of enteric infection) do not have the same disease associations as patients with celiac disease . B IgA deficiency Show explanation 8% Patients with IgA deficiency are more likely to have celiac disease .This condition tends to mask the diagnosis of celiac disease due to the high levels of IgA . However, in this case, this patient condition (i.e., history of enteric infection, tropical immigrant) does not indicate celiac disease or IgA deficiency . C Reactive arthritis Show explanation 9% Reactive arthritis is an autoimmune condition that develops in response to an infection in another part of the body ( cross-reactivity ). Patients present with a classic triad of urethritis , oligoarthritis , and conjunctivitis . Although the patient has a history of an enteric infection, the probability of reactive arthritis is less likely. D Hypoproteinemia Show explanation 14% Hypoproteinemia is a condition where there is an abnormally low level of protein in the blood This condition is often seen in patients with chronic malabsorption syndromes . In this case, the patient has a relatively acute onset of a malabsorption syndrome , thus hypoproteinemia is less likely.

22
Q

A 55-year-old man comes to the emergency department because of a 4-week history of greasy, foul-smelling diarrhea. He has had an alcohol use disorder for several decades and has been hospitalized several times in the past for a “stomach problem.” He denies fever, hematochezia, or mucus in his stools. Which of the following medication is most appropriate in the treatment of this patient?

A Esomeprazole 
B Lipase 
C Metronidazole 
D Sulfasalazine 
E Vancomycin
A

ANSWER: Lipase

Major takeaway Both acute and chronic pancreatitis can be caused by excessive alcohol intake . Replenishing certain pancreatic enzymes in affected patients has been shown to relieve pain in some cases.

Main explanation This patient is likely suffering from pancreatic insufficiency secondary to chronic pancreatitis caused by alcoholism . Pancreatic enzymes such as lipase and amylase can be used to lower the production burden on the pancreas . If the pancreas has to make less of its own enzymes, those enzymes are less likely to activate early and damage the pancreas . Classic symptoms of pancreatitis include greasy, foulsmelling stools ( steatorrhea ) caused by fat malabsorption and epigastric pain that radiates to the back. Patients often have nausea and vomiting as well. Severe pancreatitis can lead to a deficiency of the fat-soluble vitamins A , D, E, and K. Alcohol can cause pancreatitis by inducing the acinar cells of the pancreas to produce more enzymes that are then liable to activate early and damage the pancreas .

OTHER EXPLANATIONS: A Esomeprazole Show explanation 8% Esomeprazole is a proton pump inhibitor (PPI). PPIs reduce stomach acid and are commonly used to treat gastroesophageal reflux disease , H. pylori infection, and Zollinger-Ellison syndrome . This patient does not endorse heartburn or signs of a GI bleed . B Lipase Show explanation 62% C Metronidazole Show explanation 20% Metronidazole is an antibiotic that is the first-line treatment for bacterial vaginosis . It is also often used to treat C. difficile infections, which would be characterized by loose, watery diarrhea, and abdominal pain following antibiotic use. D Sulfasalazine Show explanation 6% Sulfasalazine is a drug that metabolizes to 5-ASA and is used to treat juvenile and rheumatoid arthritides , as well as ulcerative colitis (UC). UC is typically characterized by severe abdominal pain and bloody diarrhea and has no ties to alcohol . E Vancomycin Show explanation 4% Vancomycin is a powerful antibiotic used to treat MRSA and C. difficile infections. An infection with C. difficile would cause pseudomembranous colitis , which is characterized by loose, watery, nonbloody diarrhea and abdominal pain . It is not connected to alcohol use.

23
Q

A 57-year-old man with a history of alcoholism comes to the urgent care clinic because of stabbing chest pain on inspiration for the last 2 days. The patient also complains of cough, fever, fatigue and joint pain for the last week. He received a liver transplant 5 weeks ago with no surgical complications. Physical examination of the patient shows a fever of 38.1°C (100.6°F) and is otherwise unremarkable. Results from a chest radiograph are shown below. Given the time frame, which of the following best explains this patient’s symptoms?

See photo for gastroenterology 23

A Acute graft-versus-host disease 
B Chronic graft-versus-host disease 
C Cytomegalovirus infection 
D Long-term corticosteroid use 
E Parvovirus B19 infection
A

ANSWER: Cytomegalovirus

Major takeaway Cytomegalovirus (CMV) is the most common viral infection in solid organ transplant recipients. CMV infection usually develops during the first few months posttransplantation , and is associated with clinical infectious diseases and acute and/or chronic graft injury and dysfunction. It often presents with fever, fatigue, arthralgias , pneumonia , GI ulcers, and hepatitis .

Main explanation The patient in this question most likely has viral pneumonia secondary to cytomegalovirus (CMV) infection, the most common viral infection in solid organ transplant recipients. The Cytomegalovirus (CMV, HHV-5) is a double stranded DNA virus of the Herpesviridae family with a wide spectrum of infection and diseases. Approximately 20-60% of all transplant recipients develop symptomatic CMV infection , particularly when the donor was CMVseropositive and the recipient was CMV-seronegative. Like others in the Herpesviridae family, CMV infections can remain latent throughout life and may reactivate in the future, and so patients who are CMVseropositive can experience a reactivation infection. CMV infection is most commonly characterized by arthralgias , fatigue, anorexia, abdominal pain , and diarrhea. However, it can disseminate to most other organs, including the lungs, liver, intestine , brain, and kidneys, as well as cause retinitis . The most common clinical presentation of CMV pneumonia is fever, shortness of breath and pleuritic chest pain . CMV pneumonia is difficult to treat, however the drug of choice for the treatment of CMV is ganciclovir , which preferentially inhibits the DNA polymerase of CMV.

OTHER EXPLANATIONS: A Acute graft-versus-host disease Show explanation 17% Symptoms of acute liver rejection may occur as soon as 7-10 days after liver transplantation and include upper right quadrant and flank tenderness, fever, malaise , tachychardia, and hepatomegaly . There may also be a change in the patient’s mental status. Lab tests reveal elevated serum transaminase , phosphatase , and bilirubin . B Chronic graft-versus-host disease Show explanation 7% Chronic graft-versus-host disease (GVHD) can be an extension of acute GVHD or occurs de novo in patients who have not had an acute rejection . Ocular, oral, gastrointestinal, pulmonary and neuromuscular symptoms are all manifestations. Skin findings ( maculopapular exanthema ) may also be present. C Cytomegalovirus infection Show explanation 68% D Long-term corticosteroid use Show explanation 3% Side effects of acute and chronic dosing of corticosteroids include hypertension , hyperglycemia , delayed wound healing , glaucoma , hyperlipidemia , osteoporosis , suppressed growth, and risk of fungal infections. While the fever and pneumonia could be caused by a fungal infection , this is less likely than CMV in a postliver transplant patient. E Parvovirus B19 infection Show explanation 6% Though Parvovirus B19 can also cause arthralgias and mild anemia in immunocompetent adults, it usually manifests as refractory anemia in posttransplantation patients. It is also a rare post-transplant infection, unlike CMV.

24
Q

A 75-year-old African American male comes to the gastroenterology department for his scheduled screening colonoscopy. His medical history includes well-controlled hypertension, type 2 diabetes mellitus, and long-term cigarette smoking. Family history includes endometrial cancer in his mother. His endoscopic examination shows a 2 cm (0.79 in), sessile polyp approximately 6 cm (2.36 in) above the dentate line not amenable to endoscopic polypectomy. Which of the following is the most appropriate next step?

A Abdominoperineal resection with adjuvant chemoradiation therapy
B Low anterior resection, total mesorectal excision, and adjuvant chemoradiation therapy
C Multiple endoscopic biopsies of the polyp at the time of initial colonoscopy
D Neoadjuvant chemoradiation then appropriate operative intervention
E Oral and intravenous contrast-enhanced CT scan of the abdomen and pelvis

A

ANSWER: Multiple endoscopic biopsies of the polyp at the time of initial colonoscopy

Major takeaway Colorectal cancer is the third most common malignancy in the world. A high fat, low fiber diet, inflammatory bowel disease , previous radiation, and adenomatous polyps are all risk factors. When a polyp is detected incidentally multiple biopsies are necessary for pathologic evaluation.

Main explanation Colorectal cancer is the third most common malignancy in the world of which 95% are adenocarcinomas . Other than genetic risk factors, a high fat, low fiber diet, inflammatory bowel disease , previous radiation, and adenomatous polyps are all risk factors for colorectal cancer . The management of presumed colorectal cancer includes: thorough history and physical, laboratory evaluation particularly carcinoembryonic antigen (CEA) level, liver function tests , chest radiograph , and abdominal/pelvic computed tomography scan. When a polyp or mass is detected incidentally on annual screening colonoscopy , multiple biopsies or polypectomy are necessary for pathologic evaluation. If a diagnosis of cancer is made, treatment can be aimed at cure or palliation . The decision on which aim to adopt depends on various factors, including the person’s health and preferences, as well as the stage of the tumor.

OTHER EXPLANATIONS: A Abdominoperineal resection with adjuvant chemoradiation therapy Show explanation 10% Abdominoperineal resection with adjuvant chemoradiation therapy is used for biopsy proven cancer. The polyp found in this patient may be benign making radical surgical therapy unnecessary. B Low anterior resection, total mesorectal excision , and adjuvant chemoradiation therapy Show explanation 12% Low anterior resection, total mesorectal excision , and adjuvant chemoradiation therapy is used for biopsy proven cancer. The polyp found in this patient may be benign making radical surgical therapy unnecessary. C Multiple endoscopic biopsies of the polyp at the time of initial colonoscopy Show explanation 54% D Neoadjuvant chemoradiation then appropriate operative intervention Show explanation 11% Neoadjuvant chemoradiation then appropriate operative intervention is used for biopsy proven cancer. The polyp found in this patient may be benign making radical surgical therapy unnecessary. E Oral and intravenous contrast-enhanced CT scan of the abdomen and pelvis Show explanation 12% A contrast CT-scan may be helpful for detecting metastases however this patient has a single polyp that may or not be malignant. Initial biopsies are the best first step in management.

25
Q

A 58-year-old man comes to the dermatology department with a complaint of a lesion on his chin. The man says that the hole in his chin appeared out of nowhere and has grown larger over the past few months. He has applied over-the-counter antibiotic ointment and bandages but it has not healed. He has no prior surgical history. The only medication he is currently taking is cyclobenzaprine for chronic back pain. He has halitosis. He has not seen a dentist in several years, but he is going to see one soon because his mouth has been hurting. A swab of the lesion is cultured and reveals a mix of bacteria including streptococci, Bacteroides and Peptostreptococcus. Which of the following is the most likely origin of this lesion?

A Gingivitis 
B Osteomyelitis 
C Periapical abscess 
D Peritonsillar abscess 
E Pharyngitis
A

ANSWER: Periapical abscess (tooth abscess)

Major takeaway Dental caries is the breakdown of teeth by bacteria, which can lead to periapical abscesses . These abscesses , if left untreated, can cause oral-cutaneous fistulas . X-rays can provide the diagnosis. Removing the infected tooth is the mainstay of treatment.

Main explanation Oral cutaneous fistulas (also called dental sinuses , extraoral or odontogenic fistulas ) are most commonly due to the extension of a dental infection through the bone and soft tissue planes of the oral cavity . These lesions begin as bacterial infestation and tooth decay from dental caries , which penetrates the dental root and reaches the apex of the tooth to form a dental abscess . Patients with dry mouth (e.g. a history of Sjogren syndrome, use of anticholinergic medications or medications like cyclobenzaprine with anticholinergic side effects) are at an increased risk for dental caries and periapical infection due to a deficiency of antimicrobial saliva. Periapical abscesses (and the sinus tracts that they form if left untreated) can be seen as radiolucent foci on orthopantomogram or other radiographic imaging of the skull. Chronic periodontal abscesses form fistulas opening into the oral mucosa or cutaneously, depending on the path of least resistance from the origin of infection through the anatomical planes.

OTHER EXPLANATIONS: A Gingivitis Show explanation 33% Gingivitis is the local inflammation of the gums that results in painless swelling and erythema of the gums . Although gingivitis can often be characterized by bad breath , it would be unlikely to produce a cutaneous fistula . B Osteomyelitis Show explanation 11% Osteomyelitis of the jaw could produce a cutaneous fistula , but it is a less common etiology than a periapical abscess . A history of uncontrolled diabetes , bisphosphonate use, surgery or radiation of the skull would increase the likelihood of osteomyelitis . Osteomyelitis is also a potential serious complication of untreated dental abscesses . C Periapical abscess Show explanation 30% D Peritonsillar abscess Show explanation 21% Patients with peritonsillar abscesses are typically characterized by painful, asymmetric throat fullness, difficulty swallowing ( dysphagia ) and difficulty opening the mouth ( trismus ). This condition is typically not associated with cutaneous fistulas on the chin. E Pharyngitis Show explanation 5% Pharyngitis is inflammation of the pharynx causing a sore throat . Although pharyngitis can often be characterized by bad breath , it would be unlikely to produce a cutaneous fistula .

26
Q

A 35-year-old man comes to the emergency department because of sudden explosive diarrhea and intermittent abdominal pain. His medical history is relevant for recent travelling to Mexico. Upon further questioning, the patient mentions that he feels an uncontrollable urgency to defecate that does not cease after defecation. When the patient is asked about his stools, he describes them as “bloody and foul-smelling.” Physical examination shows decreased alertness, sunken eyes, dry mouth, split skin on mouth corners, and abdominal tenderness on palpation. His temperature is 38.6°C (101.48°F), pulse is 122/min, respirations are 24/min, blood pressure is 90/70 mmHg. Laboratory studies show leukocytosis and elevated alkaline phosphatase. Microscopy of a stool sample is obtained and shown below. Which of the following is the most appropriate initial treatment for this patient?

A Paromomycin 
B Metronidazole 
C Oral rehydration therapy 
D Albendazole 
E Iodoquinol
A

ANSWER: Oral rehydration therapy

Major takeaway Amoebic dysentery is caused by Entamoeba histolytica , a protozoal parasite that causes diarrhea, abdominal pain , defecation tenesmus, and fever due to the ingestion of contaminated food and/or water. In severe dehydration , the first-line treatment for acute entamoeba histolytica dysentery is oral rehydration therapy , followed by metronidazole.

Main explanation This patient’s signs and symptoms of intermittent abdominal pain , tenesmus (i.e., defecation urgency), fever, history of recent travelling, and the trophozoites in stool, is a classic presentation of an entamoeba histolytica dysentery . Amoebic dysentery is characterized as a type of gastroenteritis that results in bloody diarrhea . Entamoeba histolytica is a protozoal parasite that causes diarrhea, abdominal pain , defecation tenesmus, and fever due to the ingestion of contaminated food and/or water. Entamoeba histolytica infections are endemic in developing countries (i.e., Mexico). Protozoal parasite infections are often diagnosed in returning travelers because of an extensive incubation period (1-2 weeks). The diagnosis of entamoeba histolytica is established with stool microscopy. In this case, the stool microscopy shows the presence of trophozoites with engulfed red blood cells in the cytoplasm . Patients with dysentery have a high risk of severe dehydration . Complications of entamoeba histolytica dysentery include dehydration (most common), toxic megacolon , and bowel perforation . The first-line treatment for acute entamoeba histolytica dysentery is oral rehydration therapy and metronidazole (for 10 days). Other treatments include, paromomycin, or iodoquinol or albendazole . The prognosis is generally regarded as good, most individuals achieve a full recovery within 2-4 weeks after beginning proper treatment.

OTHER EXPLANATIONS: A Paromomycin Show explanation 5% Paromomycin is an antibiotic used to treat a number of parasite infections (i.e., amebiasis , giardiasis , tapeworm infection). It is a first line treatment for amebiasis or giardiasis during pregnancy. Although it is an amebicide medication, the patient is suffering from severe dehydration that should be treated first. B Metronidazole Show explanation 53% Metronidazole is an antiprotozoal drug that is the first-line choice against Entamoeba histolytica . It works by inhibiting nucleic acid synthesis and disrupting the DNA of microbial cells. Although it should be given along with rehydration therapy , the very first step, in this case, is to resolve moderate dehydration . C Oral rehydration therapy Show explanation 28% D Albendazole Show explanation 10% Albendazole anthelmintic drug that works by inhibiting polymerization or assembly in the microtubules . Although it can also be used to treat Entamoeba histolytica infections. It is mostly used to treat Cestodes parasites (i.e., Echinococcus granulosus ) E Iodoquinol Show explanation 5% Iodoquinol is an amebicide used against Entamoeba histolytica , and it is active against cyst and trophozoites localized in the lumen of the intestine . First-line choice for treating an asymptomatic form of amebiasis . Here, however, the patient is suffering from moderate dehydration , and therefore immediate fluid restitution should be first provided.

27
Q

A 43-year-old woman comes to the clinic because of repeated episodes of right upper quadrant abdominal pain. The pain is occasionally brought about by the ingestion of fatty foods. The pain radiates to the right shoulder and around to the back, and is accompanied by nausea and occasional vomiting. Further discussion reveals the patient, “had this whole thing happen 2 years ago.” She is afebrile, and physical examination is unremarkable. ALT and AST are elevated. Which of the following is the most likely diagnosis?

A Acute cholecystitis 
B Duodenal ulcer 
C Choledocholithiasis 
D Acute pancreatitis 
E Cholelithiasis
A

Major takeaway Choledocholithiasis refers to the presence of gallstones within the common bile duct . Patients characteristically have abdominal pain , nausea , vomiting, and cholestatic transaminitis.

Main explanation Choledocholithiasis refers to gallstones within the common bile duct (CBD). Patients with CBD stones present with abdominal pain and elevated hepatic enzymes in a cholestatic pattern, but do not demonstrate Murphy’s sign and are initially afebrile. Symptoms associated with choledocholithiasis include right upper quadrant abdominal or epigastric pain , nausea , and vomiting. Patients may have intermittent pain due to transient CBD blockage. Risk factors for choledocholithiasis include female sex, age >40 years, obesity , estrogen therapy , and a family history of gallstones . Limited right upper quadrant ultrasound , endoscopic ultrasound , and MRCP are useful diagnostic studies in the setting of suspected choledocholithiasis . ERCP should be considered a therapeutic procedure for confirmed or strongly suspected choledocholithiasis . Two potentially fatal complications of choledocholithiasis are acute cholangitis and acute pancreatitis . Acute cholangitis classically presents with leukocytosis and Charcot’s triad (fever, right upper quadrant pain, and jaundice ). In severe cholangitis , hypotension and altered mental status are also seen, completing Reynolds’ pentad. Gallstone pancreatitis typically presents with elevations in serum amylase and lipase in addition to pain, nausea , vomiting, and elevated hepatic enzymes.

OTHER EXPLANATIONS: A Acute cholecystitis Show explanation 21% Acute cholecystitis presents with colicky right upper quadrant pain, fever, and leukocytosis . Patients with cholecystitis usually present with a positive Murphy’s sign . B Duodenal ulcer Show explanation 1% Duodenal peptic ulcers typically cause a gnawing upper abdominal pain several hours after a meal , which may be relieved by eating. Risk factors for peptic ulceration include H Pylori infection, NSAID use, and smoking. Complications of duodenal ulceration include hemorrhage and perforation. C Choledocholithiasis Show explanation 32% D Acute pancreatitis Show explanation 7% The most common causes of acute pancreatitis in adults are gallstones and alcoholism . Patients with acute pancreatitis characteristically have acute upper abdominal pain lasting for days, with pain radiating to the back in approximately 50%. Other features include nausea , vomiting, fever, tachycardia , and a raised amylase on laboratory testing. E Cholelithiasis Show explanation 40% Cholelithiasis , more commonly known as gallstones , is a common condition that is generally asymptomatic. It can lead to biliary colic if a stone obstructs outflow of bile from the gallbladder . Generally, these patients will have a normal examination and normal laboratory studies.

28
Q

A 70-year-old woman is admitted to the emergency room with a one-week history of diarrhea and general weakness. She appears confused and disoriented upon admission. Her lying blood pressure is 110/70 mm Hg and sitting blood pressure is 75/45 mm Hg. Physical examination reveals that she is clinically dehydrated. Test results reveal the following: See gastroenterology question 28

Based on the patient’s symptoms and serum anion gap, which of the following is the most likely diagnosis?

A High anion gap metabolic acidosis 
B Hyperchloremic metabolic acidosis 
C Hyperkalemic metabolic acidosis 
D Hypervolemic metabolic alkalosis 
E Normal anion gap metabolic alkalosis
A

ANSWER: Hyperchloremic metabolic acidosis

Major takeaway This patient is suffering from hyperchloremic metabolic acidosis , which is also sometimes referred to as a normal anion gap metabolic acidosis . Diarrhea is the most common cause of hyperchloremic metabolic acidosis , resulting in excessive loss of fluid as well as electrolytes such as sodium , potassium, chloride , and bicarbonate .

Main explanation This patient is suffering from hyperchloremic metabolic acidosis , which is a normal anion gap metabolic acidosis . Diarrhea is the most common cause of hyperchloremic metabolic acidosis , which occurs as a result of excessive gastrointestinal loss of fluid and electrolytes such as sodium , potassium, chloride and bicarbonate in the feces. Under normal conditions, aldosterone stimulates sodium chloride reabsorption, sodium bicarbonate reabsorption, and potassium secretion in the colon . However, in cases of diarrhea, sodium chloride is preferentially reabsorbed in the colon in order to maintain blood volume , resulting in a loss of bicarbonate in the stool. This loss of bicarbonate , as indicated in this patient’s test results, causes metabolic acidosis due to a decrease in the body’s buffering capacity . More specifically, inflammatory diarrhea can lead to an excretion of 10 mmol/L of bicarbonate in the stool, while secretory diarrhea can lead to an excretion of 20–75 mmol/L. Because salt is preferentially reabsorbed, the patient will be hyperchloremic (reference range: 95–105 mmol/L). For treatment of this condition, it is often sufficient to replace extracellular fluid lost with oral or intravenous fluids and electrolytes .

OTHER EXPLANATIONS: A High anion gap metabolic acidosis Show explanation 17% Serum anion gap is equal to: [Na+] − ( [Cl−] + [HCO3−] ) In this patient: 140 − (124 + 5.5) = 10.5 mM. This is within the normal reference range of 8–16 or 4–12 mM/L (depending on the method) making this choice incorrect. High anion gap metabolic acidosis is often caused by an increase in lactic acid or kidney failure . B Hyperchloremic metabolic acidosis Show explanation 67% C Hyperkalemic metabolic acidosis Show explanation 4% D Hypervolemic metabolic alkalosis Show explanation 2% Metabolic alkalosis is a metabolic condition in which the pH of the blood has risen above 7.45, likely due to a decrease in hydrogen concentration and/or an increase in bicarbonate concentration. It has a number of causes, including vomiting, hyperaldosteronism , and kidney disorders such as Gitelman syndrome . E Normal anion gap metabolic alkalosis Show explanation 9% The patient’s serum anion gap of 10.5 mM is within the normal range. However, since this patient’s pH is below 7.35, she is not alkalotic. Serum anion gaps are typically used to distinguish different types of metabolic acidosis .

29
Q

A 25-year-old man comes to the emergency department with a fever, headache, and watery diarrhea. His abdomen has been hurting since last night. He noticed a small amount of blood in his most recent bowel movement, 2 hours ago. A stool sample is obtained and is positive for a lactose-negative, hydrogen sulfide-producing bacteria. Which of the following mechanisms is most likely responsible for causing the symptoms associated with the causative bacteria?

A Inactivation of elongation factor-2 leading to inhibition of protein synthesis by an exotoxin
B Secreted toxin that binds to stimulatory G proteins and increases intracellular cAMP
C Exotoxin that irreversibly nicks 60S ribosomes thus inhibiting protein synthesis
D Direct activation of the immune response resulting in increased intracellular cAMP,
E Toxin that inactivates inhibitory G proteins, leading to activation of adenylate cyclase

A

ANSWER: Direct activation of the immune response resulting in increased intracellular cAMP

Major takeaway Salmonella enteritidis is a lactose -negative, oxidase-negative rod that causes watery to bloody diarrhea by eliciting a host immune response that up-regulated intracellular cAMP .

Main explanation Salmonella enteritidis is a lactose -negative, oxidase-negative rod that causes watery to bloody diarrhea by eliciting a host immune response that up-regulated intracellular cAMP . Salmonella is primarily transmitted through contaminated food , such as undercooked chicken, eggs, fruit, or vegetables. In addition to contaminated food , Salmonella species can be transmitted from reptiles and amphibians as it is part of their normal flora . Symptoms of non-typhi Salmonella begin about 12-72 hours after ingestion and include fever, inflammatory diarrhea that can contain red blood cells, and abdominal cramps . The lack of hydrogen sulfide is a major distinguishing factor between Salmonella and Shigella species, particularly since bothgenera of bacteria can cause watery or bloody diarrhea . Shigella dysenteriae is lactose -negative but does not produce hydrogen sulfide . Instead it is green (versus black hydrogen sulfide ) on hektoen agar .

OTHER EXPLANATIONS: A Inactivation of elongation factor -2 leading to inhibition of protein synthesis by an exotoxin Show explanation 13% Both Corynebacterium diphtheriae and Pseudomonas aeruginosa produce an exotoxin that inactivates elongation factor -2, leading to inhibition of protein synthesis and cell death. Neither of these bacteria are associated with the gastrointestinal symptoms described in this patient. B Secreted toxin that binds to stimulatory G proteins and increases intracellular cAMP Show explanation 31% A toxin that binds to stimulatory G proteins and increases intracellular cAMP is produced by Vibrio cholerae , and is directly responsible for the symptoms of cholera . C Exotoxin that irreversibly nicks 60S ribosomes thus inhibiting protein synthesis Show explanation 20% The Shiga toxin of Shigella species, and the Shiga-like toxin of enterohemorrhagic Escherichia coli (EHEC), irreversibly nick the 60S ribosome and result in inhibition of protein synthesis. This leads to cellular death and bloody diarrhea . D Direct activation of the immune response resulting in increased intracellular cAMP , Show explanation 20% E Toxin that inactivates inhibitory G proteins , leading to activation of adenylate cyclase Show explanation 15% A toxin that inactivates inhibitory G proteins , leading to activation of adenylate cyclase is produced by Bordetella pertussis , which causes water loss into the trachea and symptoms of pertussis .

30
Q

A 64-year-old man comes to the outpatient clinic because of abdominal pain. He reports that for the last few months, he has had postprandial pain that is made worse by spicy foods. He states that the pain is oftentimes located in the right upper portion of his abdomen and feels like it’s traveling to his shoulder blade. These episodes are sporadic and unpredictable. He denies any fevers. Physical examination shows no abnormalities. Abdominal ultrasound is shown below. Which of the following is the best treatment for this condition?

See picture of gastroenterology 30

A Cholecystectomy
B Endoscopic retrograde cholangiopancreatography (ERCP)
C Magnetic Resonance Cholangiopancreatography (MRCP)
D No medical intervention
E Ursodeoxycholic acid

A

ANSWER: Cholecystectomy

Major takeaway Once gallstones become symptomatic, definitive surgical intervention with cholecystectomy is indicated. Cholecystectomy is often conducted laparoscopically, which allows for shorter post-operative recovery and better wound healing .

Main explanation Gallstone disease may be thought of as having the following 4 stages: Lithogenic state, in which conditions favor gallstone formation Asymptomatic gallstones Symptomatic gallstones , characterized by episodes of biliary colic Complicated cholelithiasis Biliary colic results when gallstones impact in the cystic duct during gallbladder contraction . Symptoms of biliary colic include sporadic postprandial abdominal pain localized to the right upper quadrant. Pain may radiate to the scapular region. The presence of fever, persistent tachycardia , hypotension , or jaundice necessitates a search for complications, which may include cholecystitis , cholangitis , or gallstone pancreatitis . Ultrasonography is the procedure of choice in suspected gallbladder or biliary disease. Gallstones appear as echogenic foci in the gallbladder . They move freely with positional changes and cast an acoustic shadow. Once cholelithiasis becomes symptomatic, definitive surgical intervention with cholecystectomy is indicated.

OTHER EXPLANATIONS: A Cholecystectomy Show explanation 66% B Endoscopic retrograde cholangiopancreatography (ERCP) Show explanation 15% Endoscopic retrograde cholangiopancreatography (ERCP) can be an indication in symptomatic choledocholithiasis or cholangitis , but is not the best treatment for this patient with biliary colic . C Magnetic Resonance Cholangiopancreatography (MRCP) Show explanation 3% MRCP is a non-invasive imaging study that is safer than ERCP because it is non-invasive; however, it is not used to treat symptoms. It is an expensive test and should not be used in this clinical scenario. D No medical intervention Show explanation 9% Asymptomatic cholelithiasis does not require immediate intervention. However, this patient is having symptoms of biliary colic and needs a cholecystectomy . E Ursodeoxycholic acid Show explanation 7% While ursodeoxycholic acid can be used as a temporary measure to dissolve the bile and allow better excretion, ursodeoxycholic acid is not the best treatment in patients with biliary colic . Bile salt therapy may be required for more than 6 months and has a success rate less than 50%.

31
Q

A 56-year-old man comes to the emergency department because of severe abdominal pain for 3 hours. He states that he has never had anything like this before and that he has vomited 4 times. He thinks his symptoms may be due to consuming some eggs that were past their expiry day. His temperature is 36.8°C (98°F), pulse is 87/min, respirations are 18/min, and blood pressure is 117/78 mm Hg. Examination shows that his abdomen is soft and non-tender. A CT scan is obtained, and a radiologist reports an incidental finding, but no acute intra-abdominal pathologies. Based on the incidental finding shown, which of the following malignancies is this patient most likely to develop?

A Colorectal carcinoma 
B Gallbladder adenocarcinoma 
C Gastric adenocarcinoma 
D Hepatocellular carcinoma 
E Pancreatic adenocarcinoma
A

ANSWER: Gallbladder adenocarcinoma

Major takeaway Porcelain gallbladder is a calcification of the gallbladder believed to be brought on by excessive gallstones . About 20-33% of porcelain gallbladders will become malignant adenocarcinomas .

Main explanation Porcelain gallbladder is a calcification of the gallbladder believed to be brought on by excessive gallstones , although the exact cause is not clear. As with gallstone disease in general, this condition occurs predominantly in overweight female patients of middle age. It is a morphological variant of chronic cholecystitis . Inflammatory scarring of the wall, combined with dystrophic calcification within the wall transforms the gallbladder into a porcelain -like vessel. Porcelain gallbladder is associated with gallbladder cancer , but the precise nature of the association is uncertain. about 20-33% of porcelain gallbladders will become malignant. This condition is often asymptomatic, and is unlikely to be related to the patient’s current complaint . Due to the increased risk for gallbladder cancer , the recommended treatment is cholecystectomy which usually includes pre-operative or intra-operative imaging of the biliary tree .

OTHER EXPLANATIONS: A Colorectal carcinoma Show explanation 12% This patient has a calcified gallbladder , which is not a risk factor for colorectal carcinoma . Risk factors for this condition include: older age, male gender, alcohol intake , and cigarette smoking . B Gallbladder adenocarcinoma Show explanation 58% C Gastric adenocarcinoma Show explanation 5% This patient has a calcified gallbladder , which is not a risk factor for gastric adencarcinoma. Risk factors for this condition include: Helicobacter pylori infection, and cigarette smoking . D Hepatocellular carcinoma Show explanation 13% This patient has a calcified gallbladder , which is not a risk factor for hepatocellular carcinoma . Risk factors for this condition include: alcoholism , viral hepatitis infection, hemochromatosis , and alpha 1-antitrypsin deficiency . E Pancreatic adenocarcinoma Show explanation 11% This patient has a calcified gallbladder , which is not a risk factor for pancreatic adenocarcinoma . Risk factors for this condition include: chronic pancreatitis , cigarette smoking , diabetes mellitus , and obesity .

32
Q

A 65-year-old woman comes to the emergency department because of mid-epigastric pain that radiates to the back. Despite attempts to alleviate the pain, it has persisted for the past 8 hours. She has not had any melena. She has a history of hyperparathyroidism. Examination shows temperature is 38°C (100.4°F), pulse is 102/min, and blood pressure is 100/70 mm Hg. Her abdomen is mildly distended, tender to palpation, with no guarding. Complete blood cell count shows no abnormalities. Serum lipase concentration is elevated. Which of the following is the greatest risk factor for the likely diagnosis?

A Helicobacter pylori 
B Acinar cell loss 
C Barrett esophagus 
D Hypercalcemia 
E Pancreatic pseudocyst
A

ANSWER: Hypercalcemia

Major takeaway Acute pancreatitis is most commonly caused by alcohol use or gallstones . Other risk factors for acute pancreatitis include hypercalcemia and hypertriglyceridemia .

Main explanation This patient has acute pancreatitis , which is likely to be secondary to hypercalcemia due to hyperparathyroidism . Commonly, patients report acute upper abdominal pain that radiates to the back. These symptoms may persist for days. Diagnostically, serum amylase and lipase concentrations rise within 4-8 hours of onset more than three times the upper limit of normal. The two most common causes of acute pancreatitis are gallstones and alcoholism . Other common causes of acute pancreatitis include hypertriglyceridemia , hypercalcemia (as in this patient), trauma, steroid use , endoscopic retrograde cholangiopancreatography , and drugs such as 6-mercaptopurines, aminosalicylates, valproic acid , and pentamidine . Mnemonic: GET SMASHED. This stands for Gallstones, Ethanol, Trauma, Steroids, Mumps, Autoimmune disease, Scorpion sting , Hypercalcemia/Hyperlipidemia, ERCP,and Drugs.

OTHER EXPLANATIONS: A Helicobacter pylori Show explanation 4% Helicobacter pylori is a gram-negative bacterium . This infection in the stomach or duodenum can lead to increased gastrin release, which leads to increased acid secretion and ultimately ulcer formation. Clinically, patients may be asymptomatic or report symptoms of epigastric abdominal pain or signs of upper gastrointestinal bleeding . B Acinar cell loss Show explanation 12% Repeated episodes of acute pancreatitis cause acinar cell loss which is a risk factor for the development of chronic pancreatitis . This patient, however, has acute pancreatitis . Chronic pancreatitis is typically characterized by prolonged, gnawing abdominal pain with radiation to the back, weight loss, and diarrhea. C Barrett esophagus Show explanation 1% Glandular metaplasia in the distal esophagus is seen in Barrett esophagus . This pathology is a complication of gastroesophageal reflux disease (GERD) and is a risk factor for esophageal adenocarcinoma . The most common complication from Barrett’s esophagus is ulceration with stricture formation. Patients would most typically report dysphagia . D Hypercalcemia Show explanation 47% E Pancreatic pseudocyst Show explanation 36% Pancreatic pseudocysts form as a complication of acute pancreatitis (which this patient has), chronic pancreatitis , or trauma. Many are asymptomatic and resolve with supportive therapy. Pseudocysts do not typically form until days or (more likely) weeks after an episode of acute pancreatitis has occurred.

33
Q

A 64-year-old man comes to the emergency department because of a 2-day history of uncontrollable nausea, vomiting, and generalized abdominal pain. His temperature is 36.8°C (98.2°F), pulse is 112/min, respirations are 20/min, and blood pressure is 104/64 mm Hg. Physical examination shows a distended abdomen with decreased bowel sounds that is tympanitic to percussion. An abdominal radiograph is obtained and is shown below. Which of the following is the most common underlying cause of the patient’s symptoms?

SEE GASTROENTEROLOGY 33

A Adhesions 
B Crohn disease 
C Intussusception 
D Strangulated hernia 
E Tumor
A

ANSWER: Adhesions

Major takeaway Small bowel obstructions are most commonly caused by bowel adhesions , and typically is characterized by an acute abdomen . A strangulated obstruction will be characterized by fever, tachycardia , and peritonism, and is a surgical emergency . Plain abdominal X-rays with supine and upright views is the best diagnostic tool for bowel obstructions.

Main explanation A small bowel obstruction is characterized by nausea , vomiting, crampy or colicky abdominal pain , and absence of bowel movements or flatus ( obstipation ). A history of malignancy, particularly ovarian and colonic, is also relevant. Abdominal distention occurs due to the obstruction. Early auscultatory findings include hyperactive bowel sounds , while hypoactive bowel sounds can be noted later. Fever, tachycardia , or peritonism, if present, are suggestive of strangulation, a surgical emergency . Early surgical intervention is also required in complete SBOs. Diagnosis is often made on plain abdominal X-rays (supine and upright views) with the presence of dilated loops of bowel with multiple (>5) air-fluid levels, proximal bowel dilation with distal bowel collapse, or a gasless abdomen . The severity of obstruction, identification of transition point, and visualization of a tumor can be better seen on abdominal CT, but is not necessary for surgical intervention. 70% of bowel obstructions are due to adhesive bowel disease. 80% of those with adhesions have had prior abdominal surgeries, the primary risk factor for this disease process. Open abdominal surgeries discover adhesions in 90% of cases, but much fewer cause the clinical symptoms seen in this patient.

OTHER EXPLANATIONS: A Adhesions Show explanation 57% B Crohn disease Show explanation 6% Intestinal inflammation secondary to Crohn disease can lead to mechanical small bowel obstruction . However, this is a much less frequent cause than adhesions and tumors, accounting for only 3-7% of all small bowel obstructions. C Intussusception Show explanation 14% Intussusception occurs when part of the bowel is pulled forward by peristalsis into a portion of immediately distal bowel . It is usually precipitated by the presence of a pathologic lead point in the bowel , usually malignancy. Intussusception is more common in children, causing only 1-5% of bowel obstruction in adults. D Strangulated hernia Show explanation 14% Hernias account for 10% of intestinal obstructions and are the third leading cause of cases. Often due to congenital or acquired defects in the mesentery , strangulated hernias would also be characterized by fever, tachycardia , and palpation of a mass due to the bowel ischemia and necrosis after strangulation. E Tumor Show explanation 8% Tumors (predominantly metastatic) are the second most common cause of small bowel obstruction . Multiple serosal small bowel metastases form confluent soft tissue masses that lead to obstruction. If present, primary tumors are most commonly gastrointestinal stromal tumors (GIST) and occur most often in the ileum .

34
Q

A 43-year-old woman comes to her primary care physician because of right upper quadrant pain. The pain occurs only after eating a fatty meal. She denies any sick contacts, fever, and chills. Her temperature is 37.6°C (99.5°F), pulse is 92/min, respirations are 18/min, and blood pressure is 125/80 mm Hg. AST and ALT concentrations are within normal limits. The right upper quadrant ultrasound of her abdomen is inconclusive because of her body habitus and a follow-up CT scan of the abdomen is ordered, the results of which are shown below. Which of the following is the most likely diagnosis?

SEE GASTROENTEROLOGY 34

A Cholelithiasis 
B Complicated choledocholithiasis 
C Intestinal obstruction 
D Splenomegaly 
E Uncomplicated choledocholithiasis
A

ANSWER: CHOLELITHIASIS

Major takeaway Cholelithiasis is characterized by postprandial right upper quadrant pain, classically after a fatty meal . Calcified cholesterol stones appear as bright, well-defined regions in the gallbladder on CT.

Main explanation There are three, well-defined , hyperintense masses within the gallbladder (beneath the liver). These are calcified gallstones (note that cholesterol -only stones may also form, but are hypointense on CT). Cholelithiasis may cause post-prandial pain, especially after the consumption of fat-rich foods, as the gallbladder contracts to release bile to aid in the digestion of the meal . The stones may temporarily block the cystic duct or irritate the contracting gallbladder , causing pain (generally, right upper quadrant or epigastric , radiating to the shoulder ). As digestion continues and less bile is needed, the gallbladder relaxes, relieving the discomfort and pain. If a stone enters the cystic duct to cause inflammation, acute cholecystitis may occur, which is characterized by continuous, intense, colicky right upper quadrant pain.

OTHER EXPLANATIONS: A Cholelithiasis Show explanation 65% B Complicated choledocholithiasis Show explanation 19% Complicated choledocholithiasis is characterized by right upper quadrant pain, fever, and abdominal guarding with right upper quadrant palpation. AST and ALT concentrations are typically elevated in the course of biliary obstruction . C Intestinal obstruction Show explanation 1% Intestinal obstruction is unlikely given the abdominal CT results, which do not show signs of focal obstruction or dilation of the colon or small bowel . There are three, well-defined , hyperintense masses within the gallbladder in this CT. D Splenomegaly The spleen is not large on this sagittal view of the abdomen and the patient does not have risk factors for splenomegaly like trauma and infectious mononucleosis . E Uncomplicated choledocholithiasis Show explanation 14% Complicated choledocholithiasis is characterized by right upper quadrant pain, fever, and abdominal guarding with right upper quadrant palpation. By definition, uncomplicated choledocholithiasis is asymptomatic, thus this answer choice can be ruled out easily.