USMLE USMLE Certifications USMLE-STEP-3 Questions & Answers

• Question 511:

  A 19-year-old female presents to the ED complaining of swelling in her left lower extremity. She reports that she had arthroscopy of the right knee about a week ago for a torn meniscus. The swelling started last night and is uncomfortable.

  Which of the following statements most accurately describes the situation?

  A. This condition is less likely to occur in women than men.

  B. The patient should be put on strict bed rest with leg elevation until her swelling resolves.

  C. Her surgically treated knee should be aspirated immediately to rule out a septic joint.

  D. Prophylaxis to prevent this complication includes subcutaneous heparin or daily coumadin.

  E. Directed lytic therapy is indicated for this patient if her lower extremity becomes bluish and has evidence of vascular compromise.

  Correct Answer: E Section: (none)

  Explanation:

  This patient has developed a DVT of her left leg. This is a complication following surgery that can be prevented in part by the use of subcutaneous heparin and sequential compression devices. Coumadin is not used as a prophylaxis, but rather as a treatment modality. Risk factors for developing DVTs include female gender, obesity, orthopedic surgery, use of oral contraceptives, smoking, and long periods of being sedentary. Her knee should be aspirated if she has a red, hot, or swollen joint; as these symptoms are not mentioned and the DVT is in the leg opposite to the surgically treated joint, aspiration is not necessary at this time.

• Question 512:

  Apatient undergoes a gastrectomy following a gunshot injury. How would you counsel him about postgastrectomy syndromes?

  A. Most patients tolerate gastrectomy without a change in their digestive habits.

  B. Dumping syndromes can be treated with high carbohydrate liquid diets.

  C. Cholestyramine is a treatment for postvagotomy diarrhea.

  D. Most patients with these syndromes require surgical intervention.

  E. Proton pump inhibitors are effective against alkaline reflux syndrome.

  Correct Answer: C Section: (none)

  Explanation:

  Most patients have a change in their digestive habits after gastrectomy. These symptoms are actually related to the vagotomy done with the operation. The majority of patients learn to manage their symptoms with only a small amount requiring surgical intervention. Dumping syndrome is associated with abdominal pain, nausea, vomiting, dizziness, and palpitations related to the quick hyperosmolar emptying into the small intestine. These symptoms can be managed by eating small, low carbohydrate meals throughout the day. Postvagotomy diarrhea is related to the rapid transit of unconjugated bile salts and is effectively treated with cholestyramine. Proton pump inhibitors are not a useful therapy for alkaline reflux.

• Question 513:

  Which of the following patients is most likely to have symptoms of the carcinoid syndrome?

  A. patient with carcinoid tumor localized to the appendix

  B. patient with carcinoid tumor of the small intestine and a 3-cm nodule in the liver seen on CT scan

  C. patient with an apple core lesion seen on barium enema

  D. patient with adrenal mass and elevated levels of urinary vanillylmandelic acid(VMA)

  E. patient with a retroperitoneal carcinoid tumor

  Correct Answer: E Section: (none)

  Explanation:

  Carcinoid syndrome is seen in less than 10% of patients with metastatic carcinoid disease. It is seen in patients with elevated serotonin levels, which is metabolized by the liver. Thus, only patients with massive hepatic metastasis or with tumors that bypass the hepatic filter--such as a retroperitoneal tumor--show symptoms. 5-Hydroxyindoleacetic acid (5-HIAA) levels can be tested in the urine to give the diagnosis (urinary vanillylmandelic acid [VMA] is indicative of a pheochromocytoma). An apple core lesion on the colon is most likely to be a large adenocarcinoma, which would not be associated with carcinoid symptoms. Common symptoms of carcinoid syndrome include flushing, diarrhea, right heart failure, and asthma. Weight loss and liver failure are uncommon symptoms.

• Question 514:

  On your surgery rotation you are assisting in a gastric surgical procedure. The attending surgeon asks you to describe the vascular supply to the stomach. You reply with which of the following?

  A. The right gastric artery arises from the celiac axis.

  B. The left gastric artery arises from the common hepatic artery.

  C. The right gastroepiploic arises from the right hepatic artery.

  D. The short gastric arteries arise from the splenic artery.

  E. The left gastroepiploic arises from the left gastric artery.

  Correct Answer: D Section: (none)

  Explanation:

  The main blood supply to the stomach comes from the right gastric artery (from the hepatic artery), the left gastric artery (from the celiac axis), the right gastroepiploic artery (from the gastroduodenal artery), the left gastroepiploic (from the splenic artery), and the short gastric arteries from the splenic artery.

• Question 515:

  A patient with dyspepsia has a positive serologic test for Helicobacter pylori and is concerned that he could have an ulcer. Which of the following statements about H. pylori and ulcer disease would be most accurate?

  A. Gastric ulcers are usually caused by hypersecretion of acid, not bacteria.

  B. A positive IgG serology confirms an active infection with H. pylori.

  C. H. pylori is associated with both gastric and duodenal ulcers.

  D. Most patients with H. pylori have ulcers.

  E. The use of antibiotics alone is successful in eradicating H. pylori.

  Correct Answer: C Section: (none)

  Explanation:

  Duodenal ulcers are usually associated with hypersecretion of acid, whereas gastric ulcers may be related to breakdown of the mucosal protective mechanisms or to malignancy. Type I gastric ulcers are the most common. They are usually associated with altered mucosal defense and not hypersecretion of acid. Type II gastric ulcers are caused by a duodenal ulcer and the resulting pyloric obstruction. Type III gastric ulcers are found proximal to the pylorus and are associated with hypersecretion and duodenal ulcers. H. pylori is found in 95% of duodenal and 80% of gastric ulcer patients. However, only 10% of people who carry the bacteria actually manifest ulcer disease. Serologic testing does not determine the presence of an active infection. Active infections can be determined by endoscopic biopsy sampling or the use of urease breath testing. All currently recommended regimens to eradicate H. pylori utilize both antibiotics and acid suppression.

• Question 516:

  You perform an upper endoscopy on a patient and find changes suggestive of Barrett's esophagus. How do you explain this to the patient and his family?

  A. Is a condition where the normal esophageal lining is replaced by columnar epithelium.

  B. Is a condition where the normal esophageal lining is replaced by dysplastic squamous cells.

  C. Two biopsies with histologic changes are needed to confirm the diagnosis.

  D. The main risk associated with Barrett's esophagus is bleeding.

  E. It is related to peptic ulcer disease.

  Correct Answer: A Section: (none)

  Explanation:

  Barrett's esophagus is related to GERD. It is found proximal to the LES and is thought to be a result of constant acidic exposure. It is a condition where the normal esophageal squamous cell epithelium is replaced by columnar epithelium, similar to intestinal metaplasia. A single biopsy is all that is needed to confirm the diagnosis. In fact, many biopsies should be taken during endoscopy if the diagnosis is suspected in an effort to find dypslasia. The risk of malignant degeneration is the most important risk associated with Barrett's esophagus.

• Question 517:

  A 60-year-old Asian male presents with early satiety and 40-lb weight loss over 3 months.Upper endoscopy shows an irregular mass in the antrum of the stomach. He follows up in the clinic a few days later, and you see that the results of the endoscopic biopsies are suggestive of a gastric lymphoma. Which of the following is true regarding this condition?

  A. The incidence of gastric lymphoma is increasing.

  B. Obstruction, perforation, and bleeding are common presenting symptoms.

  C. Upper endoscopy with biopsy is highly accurate for diagnosis.

  D. Gastric involvement of systemic lymphoma is best treated with gastric resection.

  E. Survival rates are dismal with overall prognosis similar to that seen in gastric adenocarcinoma.

  Correct Answer: A Section: (none)

  Explanation:

  Gastric adenocarcinoma is associated with dismal overall prognosis, with long-term survival seen only in patients with early stage disease. Surgical resection remains the mainstay of potentially curative therapy, with poor responses to chemotherapy in the majority of clinical trials. Patients often present with vague epigastric discomfort, occult GI bleeding/anemia, anorexia, weight loss, and even hematemesis/ vomiting. Patients are staged with endoscopic ultrasound, which is the most effective imaging modality for determining T and N stage. CT may also be useful for determining nodal metastases, but is more accurate for determining distant metastases (liver). Antral tumors may have a better prognosis than more proximal gastric tumors, with a decreased incidence of nodal metastases. Five-year survival rates for stage I disease is excellent, approaching 8090% in both the Western countries and in Asia. However, 5-year survival rates are dismal for stage III and stage IV disease, and most Western series report overall 5-year survival rates for gastric cancer of 1021%.

  In contrast to gastric adenocarcinoma in the United States, the incidence of gastric lymphoma is rising. Gastric lymphoma accounts for two-thirds of GI lymphomas. Symptoms are similar to gastric adenocarcinoma, but obstruction, perforation, and massive bleeding are very uncommon symptoms. Because gastric lymphoma spreads by submucosal infiltration, mucosal biopsies at the time of upper endoscopy can often be nondiagnostic. Repeated biopsies to obtain submucosal tissue are needed to establish a diagnosis. Treatment protocols vary among institutions, but most often center on chemotherapy; surgical resection of isolated or localized gastric lymphoma can be curative, but is rarely seen. Fortunately, survival rates for gastric lymphoma are much better than those seen in gastric adenocarcinoma, with cure rates of 70% seen in patients with stage IE and IIE disease treated with chemotherapy alone.

• Question 518:

  A 60-year-old Asian male presents with early satiety and 40-lb weight loss over 3 months.Upper endoscopy shows an irregular mass in the antrum of the stomach. What can you tell him and his family about his situation?

  A. Weight loss indicates distant metastases, and surgical resection is not indicated.

  B. Antral tumors have a worse prognosis than tumors at other sites in the stomach.

  C. CT is the most effective imaging modality for determining TNM (tumor, nodes, and metastases) stage.

  D. 5-year survival for patients with gastric adenocarcinoma confined to the mucosa with no nodal metastasis approaches 90%.

  E. Chemotherapy is an effective treatment modality in stage IV gastric adenocarcinoma, with significant benefit in overall survival.

  Correct Answer: D Section: (none)

  Explanation:

  Gastric adenocarcinoma is associated with dismal overall prognosis, with long-term survival seen only in patients with early stage disease. Surgical resection remains the mainstay of potentially curative therapy, with poor responses to chemotherapy in the majority of clinical trials. Patients often present with vague epigastric discomfort, occult GI bleeding/anemia, anorexia, weight loss, and even hematemesis/ vomiting. Patients are staged with endoscopic ultrasound, which is the most effective imaging modality for determining T and N stage. CT may also be useful for determining nodal metastases, but is more accurate for determining distant metastases (liver). Antral tumors may have a better prognosis than more proximal gastric tumors, with a decreased incidence of nodal metastases. Five-year survival rates for stage I disease is excellent, approaching 8090% in both the Western countries and in Asia. However, 5-year survival rates are dismal for stage III and stage IV disease, and most Western series report overall 5-year survival rates for gastric cancer of 1021%.

  In contrast to gastric adenocarcinoma in the United States, the incidence of gastric lymphoma is rising. Gastric lymphoma accounts for two-thirds of GI lymphomas. Symptoms are similar to gastric adenocarcinoma, but obstruction, perforation, and massive bleeding are very uncommon symptoms. Because gastric lymphoma spreads by submucosal infiltration, mucosal biopsies at the time of upper endoscopy can often be nondiagnostic. Repeated biopsies to obtain submucosal tissue are needed to establish a diagnosis. Treatment protocols vary among institutions, but most often center on chemotherapy; surgical resection of isolated or localized gastric lymphoma can be curative, but is rarely seen. Fortunately, survival rates for gastric lymphoma are much better than those seen in gastric adenocarcinoma, with cure rates of 70% seen in patients with stage IE and IIE disease treated with chemotherapy alone.

• Question 519:

  Apatient with a known family history of multiple endocrine neoplasia (MEN) I, now presents with intractable ulcer disease.

  Which of the following statements about his condition is most accurate?

  A. Diarrhea is a frequent complaint.

  B. Tumors are rarely multiple.

  C. Tumors are rarely malignant.

  D. An elevated fasting gastrin level is diagnostic for the Zollinger-Ellison syndrome.

  E. CT is useful in localizing the tumor in greater than 75% of patients.

  Correct Answer: A Section: (none)

  Explanation:

  The Zollinger-Ellison syndrome was described in 1955, in two patients with the triad of gastroduodenal ulcerations, gastric hypersecretion, and nonbeta islet cell tumors of the pancreas. Gastrinomas arise from neuroendocrine cells and represent the third most common neuroendocrine tumors (after carcinoids and insulinomas). These tumors are associated with MEN I. These tumors occur predominantly in the pancreas, duodenum, antrum, and peripancreatic lymph nodes, but can also occur at distant sites like the ovary. Isolated tumors are found in 50%, and multiple tumors in 50%, but there is a higher incidence of multiple tumors in MEN I. Tumors are malignant in 50%, with metastases to the regional lymph nodes and the liver. Once the diagnosis has been established, tumor localization can be achieved with indium-labeled octreotide scan, CT with fine cuts through the pancreas, ultrasound, MRI, or selective angiography. None of these tests are highly sensitive, and often the tumors are not localized until the time of exploration and intraoperative-directed ultrasonography.

• Question 520:

  A 59-year-old White male with a 40 pack-year history of smoking presents to your clinic complaining of three prior episodes of a "shade passing over his left eye" over the last 2 months. He reports that last week he experienced some weakness in his right arm, which resolved after 5 minutes. Appropriate management and counseling for this patient includes which of the following?

  A. Initial management of this patient should include bilateral cerebral vessel duplex ultrasonography.

  B. to him that he has had a stroke and will be referred to a neurologist for management.

  C. The most common cause of strokes in these patients is related to decreased blood flow.

  D. Presence of a carotid bruit confirms the diagnosis and may lead to operative intervention without the need for imaging studies.

  E. The presence of a 50% stenosis in the right carotid artery should lead to bilateral surgical repair.

  Correct Answer: A Section: (none)

  Explanation:

  This patient is experiencing multiple transient ischemic attacks (TIAs) associated with carotid artery disease. TIAs last only a few minutes, while RINDs (reversible ischemic neurologic deficit) typically resolve after 24 hours, and strokes result in long-term deficit. The symptoms are typically related to embolic events rather than reduced blood flow. The finding of carotid bruit on examination is more sensitive for coronary artery disease than it is for carotid disease. The initial workup for these patients should be bilateral carotid duplex ultrasound. Operative repair is indicated for asymptomatic patients with >60% stenosis as well as symptomatic patients.