True Learn #2 Flashcards
What is the most important prognostic factor for soft tissue sarcomas?
[True Learn]
Mitotic index
[The amount of necrosis is also a very important prognostic factor.]
Heparin-induced thrombocytopenia (HIT) is a paradoxical thrombotic state initiated by antibodies to what?
[True Learn]
The heparin-platelet factor IV complex
What is the best course of management of a uniloculated splenic abcess?
[True Learn]
CT-guided drainage
[multilocular lesions require splenectomy.]
What is the best diagnostic test for acute aortic dissection?
[True Learn]
Helical CT scanning
[It requires IV contrast medium that may limit its use in certain clinical situations but it generates images familiar to most practitioners and has a high sensitivity and specificity.]
What percent of a persons blood volume is lost in a class I hemorrhage?
[True Learn]
10-15% (500cc-750cc)
[This causes minimal change in the patient’s clinical condition. Slight tachycardia with a drop in pulse pressure may be the only manifestation.]
What are the two components of fibrin glue?
[True Learn]
- Fibrinogen
- Thrombin
What is the appropriate treatment for VIPoma?
[True Learn]
Distal pancreatectomy
[Surgical excision is appropriate in nearly all patients with Verner-Morrison syndrome (VIPoma). Most tumors are located in the distal pancreas where they are amenable to resection via distal pancreatectomy.]
Which type of choledochal cysts are characterized as saccular or fusiform dilation of a portion or entire common bile duct with normal intrahepatic duct and what is the treatment?
[True Learn]
- Type I choledochal cysts
- Treatment with cyst excision with Roux-en-Y jejunostomy
[Most common (80-90%) variety. This type of choledochal cyst is associated with recurrent cholangitis, progressive liver damage and high risk of cancer. The choledochal cyst wall is the primary location of carcinomas. Roux-en-Y jejunostomy is advocated because this operative approach eliminates the potentially premalignant epithelial cyst lining and also separates the pancreatic drainage from the biliary drainage.]
Which type of choledochal cysts are characterized as isolated diverticulae protruding from the common bile duct and what is the treatment?
[True Learn]
- Type II choledochal cysts
- Treatment is simple cyst resection only
[Biliary reconstruction is typically not required.]
Both intralobular and extralobular pulmonary sequestrations are found more frequently on which side of the body?
[True Learn]
Left side
[In 85% of cases, the intralobular sequestration is supplied by an anomalous systemic vessel arising from the infradiaphragmatic aorta and located within the inferior pulmonary ligament. The venous drainage is usually through the inferior pulmonary vein, but may also occur by way of systemic veins.]
What presents with nonspecific clinical features such as steatorrhea, diabetes, hypochlorhydria, and cholelithiasis, and evidence of a mass in the pancreas?
[True Learn]
Somatostatinoma
[Fasting plasma somatostatin levels of greater than 100 pg/mL can be used to confirm the diagnosis.]
What is the diagnostic modality of choice for assessing gallbladder polyps?
[True Learn]
Right upper quadrant ultrasound
[If there is any suspicion of malignancy when a gallbladder polyp is found, cross-sectional imaging with a contrast enhanced CT or MRI to determine the extent of invasion is crucial to definitive treatment and diagnosis of a malignant lesion.]
What is produced by antigen presenting cells and is involved in activation of CD4 lymphocytes?
[True Learn]
IL-1
Production of which hormone(s) can result from small cell lung cancer?
[True Learn]
- ACTH
- ADH
[Squamous cell cancer is associated with over production of PTH-related peptide leading to hypercalcemia.]
What is the treatment for a proximal gastric adenocarcinoma?
[True Learn]
Total gastrectomy
[Total gastrectomy in these patients is associated with less morbidity and mortality when compared to a subtotal gastrectomy due to the anatomical position near the GE junction. The definitive treatment for gastric adenocarcinoma is surgical resection with at least 5 cm margins. Distal tumors can usually achieve an adequate margin and a subtotal gastrectomy with 5 cm margins can be performed.]
Which structure(s) form the internal inguinal ring?
[True Learn]
The internal oblique muscle and the transversalis fascia
In treating a pseudoaneurysm, the main complication of thrombin injection is what?
[True Learn]
Thrombosis of the femoral artery
[The loss of pulses is never normal after a pseudoaneurysm and is an indication for immediate operative intervention.]
Acute aortic dissection is defined as one that presents within what time frame from the intial event?
[True Learn]
Within 2 weeks
What is the best test for both acute and chronic adrenal insufficiency?
[True Learn]
Rapid ACTH stimulation test
[Synthetic ACTH (250ug) is administered by IV, and plasma cortisol levels are measured 30 and 60 minutes later. Normal peak cortisol response should exceed 20 ug/dL. Measurement of ACTH by immunoradiometric assay is then used to distinguish primary from secondary and tertiary adrenal insufficiency. High plasma concentration of ACTH (greater than 200 pg/dL) and low plasma cortisol (less than 10 mg/dL) are diagnostic of primary adrenal insufficiency. Low levels of plasma ACTH indicate secondary (pituitary) or tertiary (hypothalamic) adrenal insufficiency.]
What are the 2 most important predictors of poor outcome in melanoma?
[True Learn]
- Distant metastasis
- Lymph node involvement
[Melanoma depth is the most powerful predictor of prognosis.]
Which breast lesion is equivalent to carcinoma in situ and will almost universally transform into invasive ductal carcinoma within 1 year?
[True Learn]
Paget’s disease of the breast
[It has high malignant potential, and when it undergoes malignant transformation, will spread lymphatically. Simple mastectomy should be first line treatment.]
What is the best conduit for repair of a lower extremity vascular injury?
[True Learn]
Contralateral greater saphenous vein
[The contralateral vein is preferred to ensure there are no venous injuries or contamination.]
What is the major fuel source for the enterocyte?
[True Learn]
Glutamine
[In times of severe stress glutamine administration has shown to decrease hospital stay, improve nitrogen balance and decrease infection rates. It is believed that these effects are due to improved barrier function in the GI tract.
What is the gold standard for the diagnosis of Hirschsprung’s disease?
[True Learn]
Rectal biopsy In the newborn period
[This is done at the bedside with minimal morbidity using a special suction rectal biopsy instrument. It is important to obtain the sample at lest 2 cm above the dentate line to avoid sampling the normal transition from ganglionated bowl to the paucity or absence of ganglia in the region of the internal sphincter.]
What is the most powerful predictor of prognosis in melanoma?
[True Learn]
Melanoma depth
[It divides melanoma into thickness categories that inversely correlate with survival. Lymph node involvement and distant metastasis are the most important predictors of poor outcome in melanoma. Positive lymph nodes = stage III disease regardless of tumor depth.]
What is the appropriate adjuvant treatment for post-menopausal females with ER-positive breast cancer who are node positive?
[True Learn]
Hormone therapy alone
[In general, all patients with positive nodes will require chemotherapy. The only exception is with post-menopausal, ER positive patients who may be treated with Anastrozole alone or Anastrozole + chemotherapy.]
How is the urine affected by metabolic alkalosis secondary to vomiting?
[True Learn]
Aciduria
[Recurrent vomiting is associated with chloride-responsive metabolic alkalosis usually as a result of loss of Cl- and H+ from the stomach. Chloride-responsive alkalosis is usually accompanied by volume depletion, which stimulates aldosterone secretion and results in reabsorption of Na+ and loss of K+. Metabolic alkalosis with hypokalemia can be associated with paradoxical aciduria due to activation of the H+/K+ exchanger to conserve potassium.]
A GI bleed in a patient with chronic pancreatitis is indicative of what?
[True Learn]
Splenic vein thrombosis
[Treatment is splenectomy.]
What is the most XRT-sensitive germ cell tumor?
[True Learn]
Seminomas
[Sarcomas (not a germ cell tumor) are known to be resistant to radiation.]
Which type of choledochal cysts are characterized as intraduodenal or intrapancreatic dilations of the distal common bile duct and what is the treatment?
[True Learn]
- Type III choledochal cysts (or choledochoceles)
- Treatment is traditionally transduodenal marsupialization of the cyst
[Increasingly choledochoceles are being treated by sphincterotomy or cyst marsupialization during an ERCP. These cysts are associated with cholangitis and pancreatitis due to the build up of protein.]
What must the predicted postoperative diffusion capacity of the lung for carbon monoxide (DLCO) be to proceed with lung resection?
[True Learn]
40% or greater
[A procedure is contraindicated if the predicted postoperative DLCO value is less than 40%.]
What is the formula for calculating the fractional excretion of sodium (FENa)?
[True Learn]
(Urine sodium x plasma creatinine)/(plasma sodium x urine creatinine) x 100
[FENa of less than 1% is pre-renal. FENa of greater than 1% is indicative of intrarenal pathology such as acute tubular necrosis or other kidney damage. FENa of greater than 4% is likely postrenal.]
Is pain alleviated by lifting the testicle (positive Prehn’s sign) in epididymitis or in testicular torsion?
[True Learn]
Epididymitis
[Epididymitis usually presents with acute testicular pain, swelling, erythema, and tenderness to palpation. Fever may also be present. Cremasteric reflex is typically present. Testicular pain is alleviated by lifting the testicle (positive Prehn’s sign).]
What is the treatment for vulvar cancers with greater than 1 mm depth?
[True Learn]
Radical vulvectomy and lymph node dissection
[Radical vulvectomy extends down to the endopelvic fascia, with a 2 cm margin, and bilateral inguinal node disection. Vulvar cancer with less than 1mm depth can be treated with wide local excision.]
At what time interval should appendectomy be performed on a patient who presents with perforated appendicitis?
[True Learn]
6-8 weeks after presentation
[Some evidence suggests that early appendectomy carries an increased risk of bowel obstruction, wound infection and reoperation.]
Where do small bowel adenocarcinomas most commonly occur?
[True Learn]
In the duodenum
What is the treatment for biliary atresia in an infant?
[True Learn]
Roux-en-Y hepatic portoenterostomy (Kasai procedure)
[The operation involves excision of the entire extrahepatic biliary tree with transection of the fibrous portal plate near the hilum of the liver. Bilioenteric continuity is then reestablished with a Roux-en-Y limb. The ultimate goal of the procedure is to allow drainage of bile from the liver into the roux limb via microscopic ductules in the portal plate.]
What is the appropriate managment of a thyroid nodule with a fine needle aspiration (FNA) that reveals follicular cells?
[True Learn]
Thyroid lobectomy
[Follicular cells seen on fine needle aspiration can not be used to make a definitive diagnosis of follicular cancer. Surgical resection is needed to rule out malignancy. The diagnosis of follicular cancer is made when capsular or vascular invasion is present. Lobectomy should be performed first since only 5-10% of nodules will contain cancer. If cancer is found, then a completion thyroidectomy should be performed at that time.]
Which type of choledochal cysts are characterized as multiple dilations in the extrahepatic and intrahepatic bile ducts and what is the treatment?
[True Learn]
- Type IVa choledochal cysts
- Treatment with cyst excision with Roux-en-Y jejunostomy
[Type IVb involve only the extrahepatic bile ducts. Type IV choledochal cysts are associated with recurrent cholangitis, progressive liver damage and high risk of cancer. The choledochal cyst wall is the primary location of carcinomas. Roux-en-Y jejunostomy is advocated because this operative approach eliminates the potentially premalignant epithelial cyst lining and also separates the pancreatic drainage from the biliary drainage.]
What is a common cause of splenic vein thrombosis?
[True Learn]
Chronic pancreatitis
[Splenic vein thrombosis causes isolated gastric varices due to retrograde flow through the short gastric and posterior gastric veins. These gastric varices only bleed about 10% of the time so prophylactic splenectomy is not indicated. An ultrasound should be performed to confirm the diagnosis.]
Which treatment modality is best for grade IV internal hemorrhoids?
[True Learn]
Hemorrhoidectomy
[The hemorrhoid is dissected off the underlying sphincter and is ligated at the apex. While this may be left open, most US surgeons reapproximate the mucosa which leads to faster wound healing.]
What percent of a persons blood volume is lost in a class IV hemorrhage?
[True Learn]
40% or greater (Greater than 2L)
[Represents a severe physiological insult. Systolic hypotension may be profound, and the diastolic blood pressure may be unobtainable. Mental status changes progress from restlessness and agitation to listlessness and obtundation, producing a moribund condition because cerebral blood flow is insufficient to maintain neurological function. Loss of more than 50% of circulating blood volume results in loss of consciousness, pulse, and blood pressure.]
Which type of thyroid cancer is derived from parafollicular cells which arise embryologically from the neural crest?
[True Learn]
Medullary thyroid carcinoma
[With the exception of medullary carcinoma, most thyroid carcinomas are derived from the thyroid follicular epithelium. Anaplastic cancer is an undifferentiated neoplasm. The ventral portion of the 4th pharyngeal pouch develops into the ultimobranchial bodies early in the development of the thyroid gland. These structures contain neural crest cells which will ultimately fuse with the thyroid and lead to the formation of the parafollicular cells. Calcitonin is the product of these “C cells”. Medullary thyroid carcinoma is a neuroendocrine neoplasm derived from the parafollicular cells and calcitonin, therefore, can be used as a surveillance marker for recurrence following resection.] Through T22 Through 42
In what order do the stomach, small bowel, and colon recover bowel function after abdominal surgery?
[True Learn]
- Small bowel
- Stomach
- Colon
[After laparotomy, small bowel motility returns within several hours, gastric motility within 24-48 hours, and colonic motility in 48-72 hours.]
What is the strongest risk factor for the development of an abdominal aortic aneurysm (AAA)?
[True Learn]
Smoking
[Degeneration of the walls of an AAA are from increases in matrix metalloproteinases and decreases in elastic and smooth muscle fibers. Family history, age, hypertension, and hypercholesterolemia are other risk factors for AAA.]
Cancer of which 3 organs are the top 3 causes of cancer death worldwide?
[True Learn]
- Lung
- Stomach
- Liver
What is the most common type of sarcoma in the GI tract?
[True Learn]
Gastrointestinal stromal (GIST) tumors
What is the most common cause for liver transplant in the USA?
[True Learn]
Hepatitis C
Which structure(s) form the external inguinal ring?
[True Learn]
External oblique aponeurosis
[The medial fibers of the external oblique aponeurosis divide into medial and lateral crura to form the external inguinal ring.]
What are the conservative measures that can be taken to treat bile reflux gastritis?
[True Learn]
Lifestyle modification, cholestryramine, metoclopramide
[This condition is most common in those that have undergone a partial gastrectomy, especially a Billroth II reconstruction. If conservative measures fail, conversion to a Roux-en-Y reconstruction is indicated.]
Which kind of pancreatic tumor can not be identified by somatostatin receptor scintigraphy (SRS)?
[True Learn]
Insulinoma
[SRS or Octreoscan has become an important imaging modality for neuroendocrine tumors of the pancreas. For most neuroendocrine tumors and carcinoid tumors, it is excellent and correctly identifies 90%. However, insulinomas are the exception, and they usually do not image on SRS.]
What presents with a dry cough, bilateral hilar adenopathy, and a pre-tibial rash?
[True Learn]
Sarcoidosis
[It can also be associated with uveitis. This is a disease in which abnormal collections of chronic inflammatory cells (granulomas) form as nodules in multiple organs. The cause of sarcoidosis is unknown. granulomas (of the non-caseating type) most often appear in the lungs or the lymph nodes, but virtually any organ can be affected. The diagnosis can be confirmed with a biopsy via bronchoscopy or open lung biopsy. Pathology will describe noncaseating granulomas.]
What can be performed as a palliative procedure in patients with unresectable pancreatic cancer and intractable pain?
[True Learn]
Celiac plexus neurolysis
[This is and endoscopic procedure performed for palliation of intractable pain in pancreatic cancer patients. It involves injection of alcohol into the celiac plexus. In one study, 59% of patients that underwent this procedure had complete relief while the other 41% had partial relief of their symptoms. At 3 months 90% maintained some level of symptom relief.]
What is the first line treatment for immune thrombocytopenic purpura?
[True Learn]
High-dose corticosteroid therapy
[IV IgG immunoglobulin is second line therapy and takes between 3-5 days to show effects. Splenectomy is indicated in patients who fail to achieve a sustained remission with medical therapy. Rituximab and Romiplostim are usually used as third line agents after splenectomy failure.]
What are the Light’s criteria?
[True Learn]
- Pleural fluid to serum protein ratio of greater than 0.5
- Pleural fluid to serum LDH ratio of greater than 0.6
[Exudative effusions will be high in protein and LDH. Other factors suggestive of an exudate are low glucose, elevated specific gravity, and a low pH.]
What is the earliest sign of hypocalcemia?
[True Learn]
Circumoral or fingertip numbness
What manifests as hypokalemia and hypertension refractory to multiple medications?
[True Learn]
Primary hyperaldosteronism
[Adrenal adenoma or bilateral adrenal hyperplasia are the 2 most common causes. The mean age at diagnosis is 50. Primary hyperaldosteronism is potentially curable when treated surgically. When there is a good response to spironolactone, the response to surgery is usually better.]
What is the order of arrival of fibroblasts, lymphocytes, macrophages, neutrophils, and platelets to populate a new wound?
[True Learn]
- Platelets
- Neutrophils
- Macrophages
- Lymphocytes
- Fibroblasts
[Platelets arrive with the early inflammatory cascade and are essential for hemostasis and initiation of the inflammatory response. Platelets release adenosine diphosphate (ADP), which, in the presence of calcium, stimulates further platelet aggregation. Platelets also release multiple cytokines that work as chemotactic agents for fibroblasts, endothelial cells, and macrophages. Neutrophils are the first cells to arrive. They are attracted to the site within 24-48 hours after injury. Neutrophils cleanse the wound via phagocytosis of bacteria and foreign debris. Macrophages are the key regulatory cells for repair and are the predominant cell type present between 48-72 hours after injury. Macrophages attract fibroblasts into the wound. Fibroblasts function to deposit collagen into the wound and assist the myofibroblast in wound contraction.]
Spigelian hernias most commonly occur below which landmark?
[True Learn]
Below the arcuate line
[Spigelian hernias often present with abdominal pain, but are difficult to identify by physical exam because the defect is covered by external oblique aponeurosis. As a result, the diagnosis is often made by imaging. Spigelian hernias most often occur below the arcuate line between the semilunar line and the lateral edge of the rectus muscle. There is a high risk of incarceration with these hernias and all do require surgical repair. The surgical approach is through a transverse abdominal incision over the defect.]
Post-transplant lymphoproliferative disorder (PTLD) results from chronic immunosuppression and is most commonly associated with which virus?
[True Learn]
Epstein-Barr virus (EBV)
[EBV is most commonly associated with the development of lymphoma in the immunosuppressed state. The severity of PTLD has a wide range and some mild cases may not need treatment. However, many patients will need to be taken off immunosuppressive medications or begin treatment with chemotherapy in more severe cases.]
What are the following characteristics of a good Lichtenstein inguinal hernia repair that have been shown to reduce recurrence and chronic pain?
- Mesh size
- Mesh shape
- Medial mesh border
- Lateral mesh border
- Superior mesh border
- Mesh size: Large mesh (7 x 15 cm)
- Mesh shape: Tracing of a foot print of tear drop
- Medial mesh border: 2 cm medial to pubic tubercle
- Lateral mesh border: 5 to 6 cm lateral to internal ring
- Superior mesh border: At least 3 to 4 cm above Hesselbach’s triangle
How are the 4 compartments of the leg opened for a fasciotomy?
- Most commonly a 2 incision technique
- Lateral incision opens the lateral and anterior compartments
- Medial incision opens the deep posterior and superficial posterior compartments
[The lateral incision is made about 3 fingerbreadths lateral to the tibia. The medial incision is made about 1 fingerbreadth posterior to the tibia.]
Rectus sheath hematomas are classified as type 1, 2, or 3. What characterizes each type?
- Type 1: Small and confined within the rectus muscle. It does not cross the midline or dissect fascial planes (Conservative Tx)
- Type 2: Confined within the rectus muscle but can dissect along the transversalis fascial plane or cross the midline (Conservative Tx unless unstable)
- Type 3: Large and usually below the arcuate line. They often present with evidence of hemoperitoneum and/or blood within the prevesical space of Retzius (Conservative Tx unless unstable)
From which pharyngeal pouches are the following 4 structures derived?
- Superior parathyroid
- Inferior parathyroid
- Thyroid
- Thymus
- Superior parathyroid: 4th pouch
- Inferior parathyroid: 3rd pouch
- Thyroid: 4th pouch
- Thymus: 3rd pouch
[The inferior parathyroid descends with the thymus, but this migration is extremely variable. Inferior glands can be found anywhere from the pharynx to the mediastinum, but are typically found within the thymus or thyrothymic ligament.]
Which two stains can be used to differentiate Merkel cell carcinoma (skin cancer) from small cell carcinoma of the lung
Cytokeratin-20 (CK-20) and Thyroid transcription factor (TFF-1)
- Merkel cell carcinoma: CK-20 (+), TFF-1 (-)
- Small cell carcinoma: CK-20 (+), TFF-1 (+)
Which three pathologic associations are found in each form of MEN syndrome?
- MEN-1: Pituitary adenoma, parathyroid hyperplasia, pancreatic tumors
- MEN-2A: Parathyroid hyperplasia, medullary thyroid carcinoma, pheochromocytoma
- MEN-2B: Mucosal neuromas, marfanoid body habitus, medullary thyroid carcinoma, pheochromocytoma
What are the boundaries of a central lymph node dissection (as in for medullary thyroid cancer)?
- Superior: Hyoid bone
- Inferior: Innominate artery
- Lateral: Carotid artery
[These are level VI lymph nodes. Thyroid cancers when metastasized to lymph nodes tend to involve level VI lymph nodes before involving levels II, III, IV, and V.]
Which maneuver can be used to gain access to the suprarenal aorta, celiac axis, proximal SMA, and proximal renal artery?
Left medial visceral rotation (Mattox maneuver)
[During this maneuver, the left colon, left kidney, spleen, tail of the pancreas, and fundus of the stomach are moved to the midline. This provides extensive exposure to the entire abdominal aorta from the diaphragmatic hiatus to the bifurcation, including access to the celiac axis, superior and inferior mesenteric arteries, and the proximal left renal artery. This maneuver can cause a splenic injury or avulsion of the left descending lumbar vein which comes of the left renal vein.]
Which maneuver can be used to gain access to the retrohepatic inferior vena cava?
Right medial visceral rotation (Cattell-Braasch maneuver)
[Also known as a super-extended Kocher manuever. Incise line of fusion of small bowel mesentery to posterior peritoneum. Rotation small bowel and right colon out of abdomen. This exposes the entire inframesocolic retroperitoneum, infrarenal aorta, IVC, bilateral renal hila, bilateral iliac vessels, and SMA vessels. This maneuver can result in injury to the SMV at the root of the mesentery.]
Where are the following vitamins/nutrients primarily absorbed?
- Calcium
- Iron
- B12
- Folic acid
- Fat soluble vitamins (D, E, A, K)
- Magnesium
- Calcium: Proximal small bowel
- Iron: Proximal small bowel (Duodenum)
- B12: Distal ileum
- Folic acid: Proximal small bowel (Jejunum)
- Fat soluble vitamins (D, E, A, K): Proximal small bowel
- Magnesium: Distal ileum and colon
[UpToDate: The proximal half of the small intestine is the predominant site for the absorption of most vitamins and minerals. A notable exception is vitamin B12, which is absorbed by a specific ileal receptor that recognizes the B12-intrinsic factor complex. Thus, extensive ileal disease or resection decreases B12 absorption and often leads to a deficiency state. As a general rule, ileal disease or resection exceeding 100 cm is associated with a high risk of B12 deficiency. This degree of ileal impairment is also associated with fat malabsorption and may thereby interfere with assimilation of fat-soluble vitamins. Another exception is magnesium. The mechanism responsible for the intestinal absorption of magnesium remains ill defined, but it occurs avidly in the distal intestine (including the colon). Patients with distal small intestinal and colonic disease are thus particularly susceptible to hypomagnesemia.]
