Block 2 Flashcards
A 45 year old male alcoholic with a history of portal hypertension presents with vomiting of blood (hematemesis) and hypotension. He denies any history of vomiting nonblood material or retching prior to vomiting blood. During workup he dies suddenly. Which of the following histologic changes is most likely to be seen in a biopsy specimen taken from his esophagus?
A. Metaplastic columnar epithelium
B. Numerous intraepithelial neutrophils
C. Decreased ganglion cells in the myenteric plexus
D. Mucosal outpouchings
E. Dilated blood vessels in the submucosa
E. Dilated blood vessels in the submucosa
Pretest
A 31 year old has had a 10 year history of intermittent, bloody diarrhea. She has no other major medical problems. Colonoscopy reveals a friable, erythematous mucosa with focal ulceration that extends from the rectum to the mid-transverse colon. Biopsies are taken and all reveal mucosal acute and chronic inflammation with crypt distortion, occasional crypt abscesses, and superficial mucosal ulceration. The patient is at greatest risk for development of which of the following conditions:
A. Perirectal fistula B. Diverticulitis C. Sclerosing cholangitis D. Acute pancreatitis E. Appendicitis
C. Sclerosing cholangitis
Webpath
A 39 year old man is having a routine physical examination because of a history of colon cancer in his family He has no abdominal tenderness or masses, and active bowel sounds are present. However, his stool is positive for occult blood. Colonscopy is performed. There are 7 polyps found in the ascending colon: three of these are small 0.5 cm pedunculated tubular adenomas, three are 1 cm tubulovillous adenomas, and one is a 2 cm sessile villous adenoma in the cecum containing a focus of well differentiated adenocarcinomas, Which of the following conditions best explains these findings:
A. Gardner's syndrome B. Hereditary non-polyposis colon carcinoma C. Peutz-Jehgers syndrome D. Familial polyposis coli E. Chronic ulcerative colitis
B. Hereditary non-polyposis colon carcinoma
Webpath
A newborn infant is noted to have coughing and cyanosis during feeding. This infant is also noted to have marked gastric dilation due to “swallowed” air. Workup reveals that this infant has the most common type of esophageal atresia. Which of the following statements correctly describes this type of congenital abnormality?
A. Atresia of the esophagus with fistula between the trachea and the blind upper segment
B. Atresia of the esophagus with fistula between the trachea and the distal esophageal segment
C. Atresia of the esophagus with fistula between both segments and the trachea
D. Atresia of the esophagus without tracheoesophageal fistula
E. Fistula between a normal esophagus and the trachea
B. Atresia of the esophagus with fistula between the trachea and the distal esophageal segment
Pretest
A 45 year old male alcoholic with a history of portal hypertension presents with vomiting of blood (hematemesis) and hypotension. He denies any history of vomiting nonblood material or retching prior to vomiting blood. During workup he dies suddenly. Which of the following histologic changes is most likely to be seen in a biopsy specimen taken from his esophagus?
A. Mucosal outpouchings
B. Decreased ganglion cells in the myenteric plexus
C. Dilated blood vessels in the submucosa
D. Numerous intraepithelial neutrophils
E. Metaplastic columnar epithelium
C. Dilated blood vessels in the submucosa
Pretest
A 49 year old woman taking ibuprofen for increasing joint pain in her hands presents with increasing pain in her midsternal area. Gastroscopy reveals multiple, scattered, punctate hemorrhagic areas in her gastric mucosa as seen in the picture below. Biopsies from one of these hemorrhagic lesions reveal musocal erosions with edema and hemorrhage. No mucosal ulceration is seen. Which of the following is most likely diagnosis?
A. Peptic ulcer disease B. Active chronic gastritis C. Acute gastritis D. Chronic gastritis E. Autoimmune gastritis
C. Acute gastritis
Pretest
A 20 year old patient undergoes a total colectomy because of a family history of colon cancer at a young age. In the resected colon are over 200 tubular adenomas ranging in size from 0.2 to 1 cm on gross examination. He is otherwise healthy, with no other lesions present. Which of the following genetic conditions is most likely to account for these findings:
A. Hereditary non-polyposis colon carcinoma syndrome B. Adenomatous polyposis coli C. Multiple endocrine neoplasia D. Peutz-Jehgers syndrome E. Gardner's syndrome
A. Hereditary non-polyposis colon carcinoma syndrome
A 53 year old man presents with increasing gastric pain and is found to have a 3 cm mass located in the anterior wall of his stomach. This mass is resected and histologic examination reveals a tumor composed of cells having elongated, spindle-shaped nuclei. The tumor does not connect to the overlying gastric epithelium and is instead found only in the wall of the stomach. The tumor cells stain positively with CD117, but negatively with both desmin and S-100. Special studies find that these tumor cells have abnormalities of the KIT gene. Which of the following is the most likely diagnosis?
A. Lymphoma of mucosa-associated lymphoid tissue (MALToma)
B. Ectopic islet cell adenoma (VIPoma)
C. Gastrointestinal stromal tumor (GIST)
D. Submucosal leiomyoma (“fibroid tumor”)
E. Nonchromaffin paraganglioma (chemodectoma)
C. Gastrointestinal stromal tumor (GIST)
A 2 week old neonate presents with regurgitation and persistent, severe projectile vomiting. An olive-like epigastric mass is felt during physical examination. A chest c-ray does not reveal the presence of bowel gas in the chest cavity. This infant’s mother did not have polyhydramnios during this pregnancy. Which of the following is the most appropriate treatment for this infant’s condition?
A. Surgery to resect an aganglionic section of the intestines
B. Oral medication with vancomycin or metronidazole
C. Surgery to cut a hypertrophied stenotic band at the pylorus
D. Oral medication with omeprazole and clarithromycin
E. Surgery to remove a mass of the adrenal gland
C. Surgery to cut a hypertrophied stenotic band at the pylorus
A 45 year old man has had malabsorbtion for the past year associated with a low volume, non-bloody diarrhea. He also has a polyarthritis and complains of occasional visual hallucinations. An abdominal CT scan reveals no masses, only generalized lymphadenopathy. On upper GI endoscopy, there are no esophageal or gastric lesions, but there are broad, flattened villi in the duodenum. Biopsies of the duodenum reveal numerous PAS-positive macrophages in the submucosa. Which of the following therapies is indicated for this patient?
A. A gluten-free diet B. Antibiotics C. Antacids D. Segmental duodenal resection E. Corticosteroids
B. Antibiotics
Ischemia with infarction of the small intestine is LEAST likely to occur with which of the following conditions:
A. Volvulus B. Intussusception C. Regional enteritis D. Incarcerated hernia E. Superior mesenteric artery thrombosis
C. Regional enteritis
A 39-year-old female presents with the new onset of a bloody dis- charge from her right nipple. Physical examination reveals a 1-cm freely movable mass that is located directly beneath the nipple. Sections from this mass reveal multiple fibrovascular cores lined by several layers of epithelial cells. Atypia is minimal. The lesion is completely contained within the duct and no invasion into underlying tissue is seen. What is the correct diagnosis?
a. Benign phyllodes tumor
b. Ductal papilloma
c. Intraductal carcinoma
d. Paget’s disease
e. Papillary carcinoma
b. Ductal papilloma
Pretest
A 41 year old man has a history of drinking 1 to 2 liters of whiskey per day for the past 20 years. He has had numerous episodes of nausea and vomiting in the past. However, he experiences a bout of prolonged vomiting, followed by massive hematemesis. In the emergency room of the hospital, he has vital signs with T 36.6 C, R 24, P 110, and BP 80/40 mm Hg. On physical examination, his heart has a regular and rhythm with no murmurs and his lungs are clear to auscultation. There is no abdominal tenderness or distension of bowel sounds are present. His stool is negative for occult blood. Which of the following conditions is he most likely to have
A. Hiatal hernia B. Esophageal laceration (Mallory-Weiss syndrome) C. Esophageal pulsion diverticulum D. Barrett esophagus E. Esophageal squamous cell carcinoma F. Esophageal stricture
B. Esophageal laceration (Mallory-Weiss syndrome)
Webpath
A 25 year old man complains of a low volume but chronic, foul smelling diarrhea for the past year. He has no nausea, vomiting, or abdominal pain. On physical examination he has skin lesion looks like a herpes lesion. A stool fat collection indicates steatorrhea. A stool sample for occult blood is negative. Upper GI endoscopy and biopsy of the duodenum is performed. The biopsy reveals the absence of villi, increased surface intraepithelial lymphocytes. Which of the following therapies is indicated:
A. Corticosteroids B. Gluten-free diet C. Vagotomy D. Segmental duodenal resection E. Antibiotics
B. Gluten-free diet
An 18 year old woman presents with abdominal pain localized to the right lower quadrant, nausea and vomiting, mild fever, and an elevation of the peripheral leukocyte count to 17,000/iL. An appendectomy is performed. Which of the following statements best describes the expected microscopic appearance of her appendix?
A. A yellow tumor nodule at the tip of the appendix
B. Lymphoid hyperplasia and multinucleated giant cells within the muscular wall
C. An appendix with a normal appearance
D. A dilated lumen filled with mucus
E. Neutrophils within the muscular wall
B. Lymphoid hyperplasia and multinucleated giant cells within the muscular wall
A 23-year-old man has been feeling tired for 3 weeks. On physical examination, there is no abdominal tenderness and no masses are noted. Bowel sounds are present. His stool is positive for occult blood. Laboratory studies show a hemoglobin of 9 g/dL with hematocrit 26.3%, MCV 72 fL, platelet count 189,000/microliter, and WBC count 7500/microliter. A small bowel radiographic series with barium reveals no masses or perforations, only a solitary 2 cm outpouching in the ileum. Which of the following conditions has most likely led to these findings?
A. Inheritance of a faulty APC gene
B. Ulceration of mucosa by ectopic gastric tissue
C. Proliferation of abnormal submucosal veins
D. Elaboration of enterotoxin by Escherichia coli
E. Antiphospholipid antibody
B. Ulceration of mucosa by ectopic gastric tissue
Webpath
A 39-year-old female presents with chronic abdominal cramps, watery diarrhea, and periodic facial flushing. Physical examination reveals wheezing and a slightly enlarged liver. Workup reveals several masses within the liver and a large mass in the small intestine. Which one of the listed substances is most likely to be elevated in the urine of this individual as a result of her disease?
a. 5-hydroxyindoleacetic acid (5-HIAA)
b. Aminolevulinic acid (ALA)
c. N-formiminoglutamate (FIGlu)
d. Normetanephrine
e. Vanillylmandelic acid (VMA)
a. 5-hydroxyindoleacetic acid (5-HIAA)
Pretest
A 45 year old man presents with increasing “heartburn” especially after eating or when lying down. Endoscopic examination finds a red velvety plaque located at the distal esophagus. Biopsies from this area, taken approximately 4 cm proximal to the gastroesophageal junction reveals metaplastic columnar epithelium. Which of the following is the most likely diagnosis?
a. Acquired achalasia
b. Barrett’s esophagus
c. Hamartomatous polyp
d. Metastatic adenocarcinoma
b. Barrett’s esophagus
A 55 year old male present with dyspnea on exertion. chest xray shows nodular densities in both lung fields, most prominent in apical region. Calcified hilar lymph nodes were also present. A calcified node is sampled, and polarizeed microscopy shows birefringent particles surrounded by dense collagen fibers. This patient most likely has a history of exposure to:
A. Organic dust B. Berillium C. Coal Dust D. Silica E. Asbestos
D. Silica
A 35 year old male with recurrent hemoptysis is foun don chest X-ray to have apical infiltrative cavitary lung lesions. Sputum culture shows acid fast bacilli. Which of the following is the most likely mechanism of tissue damage in this patient?
A. Bacterial toxin induced cell necrosis
B. Exudation and alveolar hepatization
C. Delayed type hypersensitivity
D. Intra alveolar bacterial overgrowth
E. Obliterative lower airway inflammation
C. Delayed type hypersensitivity
A mediastinal mass in a 65 year old smoker is biopsed. Histology demonstrated cluster of ovoid cells that are smaller than resting lymphocytes. Immohistochemical staining is positive for neuron specific enolase, chromagranin and synaptophysin. The mass most likely represents:
A. Squamous cell carcinoma B. Small cell carcinoma C. Large cell carcinoma D. Adenocarcinoma E. Bronchoalveolar carcinoma
B. Small cell carcinoma
BLOCK 1
A 43 year old African American women presents to the hospital complaining of several weeks of malaise, 10 pound weight loss, nocturnal fevers and cough. She has no appreciable past medical history and has not had any recent travel but is a former prisoner. Her chest xray shows some hilar prominence, a palpable node in the supraclavicular bed is biopsied and pathology reveals well-formed, non-caseating granulomas. What is the most likely diagnosis?
A. Mycobacterium tuberculosis
B. Adenocarcinoma of the lung metastatic
C. Squamous cell carcinoma of the lung, metastatic
D. Sarcoidosis
E. Mycobacterium avium complex (MAC)
F. Hodgkin’s lymphoma
G. HIV infection
D. Sarcoidosis
BLOCK 1 While recovering in bed 1 week after an abdominal hysterectomy, a 42 year old woman develops acute shortness of breath with hemoptysis. Physical examination finds the patient to be afebrile with moderate respiratory distress, calf tenderness, and a widely split S2. Which of the following is the most likely diagnosis? A. Atelectasis B. Bacterial pneumonia C. Pulmonary embolus D. Pulmonary hypertension E. Viral pneumonia
C. Pulmonary embolus
BLOCK 1
A 62 year old female presents to your office with cough and dyspnea. She expectorates copious amounts of a pale tan-colored fuild. Chest xray reveals a pulmoary infiltrate that is subsequently biopsied. Histological examination reveals columnar mucin-seceting cells that fill the alveolar spaces without invading the stroma or vessels. This patient’s condition is best characterized as
A. Interstitial pneumonia B. Pneumoconiosis C. Hypersensitivity pneumonitis D. Pulmonary infarction E. Benign neoplasm F. Malignant neoplasm
F. Malignant neoplasm
A 46 year old homeless alcoholic man presents to the emergency room complaining of fevers, night sweats, weight loss, and productive cough. He describes his sputum as greenish and foul smelling. His temperature is 39 deg C(103 deg F), blood pressure is 110/65 mm Hg, pulse is 102 beats per minute, and respirations are 22 per minute. Chest x ray reveals a cavitary lesion in the middle lobe of the right lung with air fluid levels. Which of the following is the most likely cause of his condition?
a. aspiration of gastric contents
b. aspiration of oropharyngeal contents
c. hematogenous spread from another focus of infection
d. primary mycobacterial infection
e. chronic aspergillus infection.
b. aspiration of oropharyngeal contents
BLOCK 1
A 54-year-old male presents to the physician because of difficulty rising from a chair. He was recently diagnosed with a lung cancer. Physical examination shows hip girdle weakness. Electrophysiological studies show a remarkable increase in the muscle response on repetitive motor nerve stimulation. This patient’s condition is most likely associated with which of the following?
A. Segmental axonal demyelination
B. Antibodies against presynaptic calcium channels
C. Antibodies against postsynaptic acetyl choline receptors
D. Medication-induced muscle fiber atrophy
E. Perifascicular muscle inflammation
B. Antibodies against presynaptic calcium channels
A 37 year old woman presents with the acute onset of a productive cough, fever, chills, and pleuritic chest pain. A chest xray reveals consolidation of the entire lower lobe of her right lung. She unexpectedly dies before treatment due to cardiac arrhythmia. Histologic examination of lung tissue taken at the time of autopsy reveals multiple suppurative, neutrophil rich exudates filling the bronchi, bronchioles, and alveolar spaces. The majoritiy of lung tissue from her right lower lung is involved int his inflammatory process. Hyaline membranes are not found. Which of the following is the most likely diagnosis?
A. Bronchiectasis B. Bronchopneumonia C. Interstitial pneumonitis D. Lobar pneumonia E. Pulmonary abscess
D. Lobar pneumonia
A 68 year old man who worked for many years int he asbestos industry presents with weight loss and increasing chest pain. Examination of his sputum finds very rare asbestos bodies, while a CT scan shows a large mas involving the basal surface of his left lung. Surgery is performed and gross examination finds a lesion similar in appearance to that seen in the associated gross photograph of a sagittal section of the lung. Sections from this mass examined by electron microscopy reveal tumor cells with long microvilli on their surface. Which of the following is the most likely diagnosis?
A. Malignant mesothelioma B. Malignant thymoma C. Metastatic malignant melanoma D. Poorly differentiated adenocarcinoma E. Small-cell carcinoma
A. Malignant mesothelioma
A 36 year old man with AIDS presents with fever, dry cough, and dyspnea. A chest xray shows bilateral and diffuse infiltrates. Laboratory studies reveal a CD4+ cell count of less than 200/uL. A lung biopsy discloses a chronic interstitial pneumonitis and an intra-alveolar foamy exudate. A silver stain of a bronchoalveolar lavage is shown in the image. Which of the following organisms is the most likely pathogen responsible for these pulmoary findings?
A. Cryptococcus neoformans B. Cytomegalovirus C. Histoplasma capsulatum D. Mycoplasma pneumoniae E. Pneumocystis jiroveci
E. Pneumocystis jiroveci
A 68 year old man complains of shortness of breath, hoarse-ness, productive cough, and bloody sputum of 2 weeks in duration. He admits to smoking two packs a day for 45 years and drinks occasionally. Recently, he has experienced a significant loss of appetite and weight loss. Physical examination shows pallor, cachexia, clubbing of the fingers, and barrel-shaped chest. A chest xray reveals a mass at the right lung apex. Histologic examination of a trans-bronchial biopsy is shown in the image. What is the appropriate histologic diagnosis?
A. Adenocarcinoma B. Mesothelioma C. Metastatic adenocarcinoma D. Small cell carcinoma E. Squamous cell carcinoma
E. Squamous cell carcinoma
A 48 year old woman with a long standing history of ulcerative colitis presents with anemia and hortness of breath. Laboratory studues show increased serum levels of carcinoembryonic antigen. A chest ray reveals multiple round masses in both lungs. Histologic examination of an open-lung biopsy discolses nodules that are composed of gland-like structures. WHat is the most likely diagnosis?
A. Adenocarcinoma B. Bronchioloalveolar carcinoma C. Eosinophilic granuloma D. Large cell undifferentiated carcinoma E. Metastatic carcinoma
E. Metastatic carcinoma
Fine needle aspiraton of a pulmonary lesion in a 35 year old alcoholic female is performed. The specimen is cultured, and grows several bacterial species, including peptostreptococcus and prevotella. The most likely predisposing factor in this patients condition is:
A. Mitral valve prolapse B. Chest trauma C. Urinary infection D. Sepsis E. Repeated vomiting F. Occult malignancy
E. Repeated vomiting
A newborn infant is noted to have coughing and cyanosis during feeding. This infant is also noted to have marked gastric dilation due to “swallowed” air. Workup reveals that this infant has the most common type of esophageal atresia. Which one of the listed statements correctly describes this type of congenital abnormality?
a. Atresia of the esophagus with fistula between both segments and the trachea
b. Atresia of the esophagus with fistula between the trachea and the blind upper
segment
c. Atresia of the esophagus with fistula between the trachea and the distal
esophageal segment
d. Atresia of the esophagus without tracheoesophageal fistula
e. Fistula between a normal esophagus and the trachea
C.Atresia of the esophagus with fistula between the trachea and the distal
esophageal segment
A 49-year-old female presents with increasing problems swallowing food (progressive dysphagia). X-ray studies with contrast reveal that she has a markedly dilated esophagus above the level of the lower esophageal sphincter (LES). No lesions are seen within the lumen of the esophagus. This patient’s symptoms are most likely caused by
a. Decreased LES resting pressure
b. Absence of myenteric plexus in the body of esophagus
c. Absence of myenteric plexus at the LES
d. Absence of submucosal plexus in the body of esophagus
e. Absence of submucosal plexus at the LES
b. Absence of myenteric plexus in the body of esophagus
A 45-year-old male alcoholic with a history of portal hypertension presents with vomiting of blood (hematemesis) and hypotension. He denies any history of vomiting nonblood material or retching prior to vom- iting blood. During workup he dies suddenly. Based on his history and physical findings, histologic sections from his esophagus would most likely reveal
a. Columnar epithelium in the distal esophagus
b. Decreased ganglion cells in the myenteric plexus
c. Dilated blood vessels in the submucosa
d. Mucosal outpouchings (diverticula) in the distal esophagus
e. Numerous intraepithelial neutrophils with scattered eosinophils
c. Dilated blood vessels in the submucosa
The photomicrograph below shows an esophageal biopsy taken 10 cm above the lower esophageal sphincter. This condition is most likely to occur as a result of
a. Destruction of the ganglion cells in Auerbach’s plexus
b. Ingestion of lye
c. Long-term gastroesophageal reflux
d. Portal hypertension with portacaval shunting
e. Vomiting against a closed lower esophageal sphincter
c. Long-term gastroesophageal reflux
A 71-year-old male presents with dysphagia and is found to have a 5-cm mass that is located in the middle third of the esophagus and extends into adjacent lung tissue. A biopsy from this mass would most likely reveal
a. A mass composed of benign cartilage
b. A mass composed of benign smooth-muscle cells
c. Infiltrating groups of cells forming glandular structures
d. Infiltrating sheets of cells forming keratin
e. Infiltrating single cells having intracellular mucin
d. Infiltrating sheets of cells forming keratin
A 2-week-old neonate presents with regurgitation and persistent, severe projectile vomiting. An olive-like epigastric mass is felt during phys- ical examination. A chest x-ray does not reveal the presence of bowel gas in the chest cavity. This infant’s mother did not have polyhydramnios during this pregnancy. What is the best treatment for this infant’s condition?
a. Oral medication with omeprazole and clarithromycin
b. Oral medication with vancomycin or metronidazole
c. Surgery to cut a hypertrophied stenotic band at the pylorus
d. Surgery to remove a mass of the adrenal gland
e. Surgery to resect an aganglionic section of the intestines
c. Surgery to cut a hypertrophied stenotic band at the pylorus
A 49-year-old female taking ibuprofen for increasing joint pain in her hands presents with increasing pain in her midsternal area. Gastroscopy reveals multiple, scattered, punctate hemorrhagic areas in her gastric mucosa. Biopsies from one of these hemorrhagic lesions reveal mucosal erosions with edema and hemorrhage. No mucosal ulceration is seen. What is the best diagnosis?
a. Active chronic gastritis
b. Acute gastritis
c. Autoimmune gastritis
d. Chronic gastritis
e. Peptic ulcer disease
b. Acute gastritis
A biopsy of the antrum of the stomach of an adult who presents with epigastric pain reveals numerous lymphocytes and plasma cells within the lamina propria, which is of normal thickness. There are also scattered neu- trophils within the glandular epithelial cells. A Steiner silver stain from this specimen is positive for a small, curved organism, which is consistent with
a. Enteroinvasive Escherichia coli
b. Enterotoxigenic E. coli
c. Helicobacter pylori
d. Salmonella typhi
e. Shigella species
c. Helicobacter pylori
A 51-year-old male presents with epigastric pain that is lessened whenever he eats. A gastroscopy is performed to evaluate these gastric symptoms and a solitary gastric ulcer is seen. This ulcer is round and has punched-out straight walls. The margins of the ulcer are slightly elevated, and gastric rugae radiate outward from the ulcer. Based on these findings, in order to relieve the epigastric pain this patient should
a. Take indomethacin twice a day
b. Abstain from smoking
c. Eat only two meals per day
d. Drink alcohol with his evening meal
e. Have surgery to resect the ulcer
b. Abstain from smoking
Gastric tumors with the histologic appearance illustrated in the pho- tomicrograph below are likely to have a gross appearance described best by which one of the listed terms?
a. Cystosarcoma phyllodes
b. Linitis plastica
c. Peau d’orange
d. Rodent ulcer
e. Sarcoma botryoides
b. Linitis plastica
The overall incidence of malignancies of the stomach in the United States is decreasing primarily due to a decreased incidence of
a. Signet ring carcinoma
b. Primary non-Hodgkin’s lymphoma
c. Intestinal-type gastric carcinoma
d. Gastric stromal sarcoma
e. Diffuse gastric carcinoma
c. Intestinal-type gastric carcinoma
The congenital abnormality of the ileum illustrated below
a. Is present in approximately 20% of normal persons
b. Is lined by heterotopic gastric mucosa in less than 2% of cases
c. Often shows mucosal ulceration
d. Is related to persistence of the vitellointestinal duct
e. Usually arises from the mesenteric border of the ileum
d. Is related to persistence of the vitellointestinal duct
The signs and symptoms in which one of the listed individuals are most likely to be due to intussusception of the bowel?
a. An 18-year-old male with fever, leukocytosis, and right lower quadrant abdom- inal pain
b. A 3-year-old child with the abrupt onset of colicky abdominal pain and bloody, “currant jelly” stools
c. A 55-year-old male with the acute onset of severe abdominal pain
d. A 67-year-old female with fever, leukocytosis, and left lower quadrant abdomi-
nal pain
e. A newborn infant with projectile vomiting and midepigastric mass
b. A 3-year-old child with the abrupt onset of colicky abdominal pain and bloody, “currant jelly” stools
A 10-month-old, previously healthy male infant develops a severe, watery diarrhea 2 days after visiting the pediatrician for a routine checkup. The most likely diagnosis is
a. Rotavirus infection
b. Enterotoxigenic E. coli infection
c. Entamoeba histolytica infection
d. Lactase deficiency
e. Ulcerative colitis
a. Rotavirus infection
