MCQ Book Questions

Q60442. A 23-year-old woman with a history of an eating disorder complains of vomiting, nausea, and severe abdominal pain. Physical examination shows abdominal distension and consti- pation. An X-ray fi lm of the abdomen reveals air-fl uid levels and a hyperlucent shadow at the epigastric area. The material obstructing the gastrointestinal tract is removed surgically and shown. Which of the following is the most likely diagnosis?

Q60443. A 63-year-old woman complains of rectal bleeding of 1 week in duration. Laboratory studies show hypochromic, micro- cytic anemia (hemoglobin = 7.6 g/dL and MCV = 70 μm3). Colonoscopy reveals a large polypoid mass, which is removed (surgical specimen shown in the image). The arrow points to a malignant tumor. The patient asks about the relative risk of cancer arising in various types of gastrointestinal polyps. Which of the following types of colonic polyps is most likely to undergo malignant transformation?

Q60444. A 59-year-old man complains of progressive weakness. His friends have noticed that he has become pale, and he reports that his stools are tinged with blood. On abdominal palpa- tion, there is fullness in the right lower quadrant. Laboratory studies show iron-defi ciency anemia, with a hemoglobin level of 7.4 g/dL. Stool specimens are positive for occult blood. Colonoscopy reveals an elevated and centrally ulcerated lesion of the sigmoid colon. The biopsy is shown in the image. Which of the following is the most likely diagnosis?

Q60445. A 55-year-old man undergoes routine colonoscopy. A small, raised, mucosal nodule measuring 0.4 cm in diameter is iden- tifi ed in the rectum and resected. The surgical specimen is shown in the image. Microscopic examination reveals goblet cells and absorptive cells with exaggerated crypt architecture, but no signs of nuclear atypia. Which of the following is the most likely diagnosis?

Q60446. A 65-year-old woman undergoes routine colonoscopy. During the procedure, a 2-cm mass is identifi ed in the rectosigmoid region and resected. The surgical specimen is shown in the image. Microscopic examination shows irregular crypts lined by pseudostratifi ed epithelium with hyperchromatic nuclei, without dysplastic features. Which of the following is the most likely diagnosis for this patient’s colonic lesion?

Q60447. A 60-year-old woman complains of increasing abdominal girth of 4 weeks in duration. Physical examination discloses ascites, and cytologic examination of the fl uid reveals malignant cells. Exploratory laparotomy shows multiple tumor nodules on the serosal surface of the intestines. Which of the following is the most likely diagnosis?

Q60448. A 34-year-old man with AIDS presents with a 3-month history of constipation and lower abdominal pain. The patient has a history of chronic diarrhea and persistent cough. Recently, he noticed blood in his stool. Laboratory studies reveal mild iron- defi ciency anemia. Stool specimens are positive for occult blood. A CBC shows a CD4 count of less than 50/μL. Sigmoidoscopy discloses a mass in the rectosigmoid region. In addition to B-cell lymphoma, this patient is at increased risk of developing which of the following tumors of the gastrointestinal (GI) tract?

Q60449. A 27-year-old woman presents with a 9-month history of bloody diarrhea and crampy abdominal pain. Three weeks ago, she noticed that her left knee was swollen, red, and pain- ful. Her temperature is 38°C (101°F), respirations are 32 per minute, and blood pressure is 130/90 mm Hg. Abdominal pal- pation reveals tenderness over the left lower quadrant. Labora- tory studies show moderate anemia, with a hemoglobin level of 9.3 g/dL. Microscopic examination of the stool reveals numer- ous red and white blood cells. A diffusely red, bleeding, friable colonic mucosa is visualized by colonoscopy. The colon is sub- sequently removed and the surgical specimen is shown in the image. Which of the following is the most likely diagnosis?

Q60450. A portion of the large bowel was removed from a 34-year-old man with a familial disease that affects his gastrointestinal tract. The surgical specimen is shown in the image. This patient most likely carries a germline mutation in which of the following genes?

Q60451. A 65-year-old woman presents with a 3-month history of diarrhea and abdominal pain. She has lost 9 kg (20 lb) in the past 6 months. The patient had two benign colonic pol- yps removed 3 years ago. Laboratory studies reveal mild iron-defi ciency anemia, and stool specimens are positive for occult blood. Sigmoidoscopy demonstrates an ulcerated mass, and a biopsy shows malignant glands. A segment of the colon is resected, and the surgical specimen is shown in the image. Based on current models of colonic carcinogen- esis, which of the following genes was most likely mutated in the transition from benign adenoma to carcinoma in this patient?

Q60452. A 24-year-old man is brought to the emergency room with symptoms of acute intestinal obstruction. His temperature is 38°C (101°F), respirations are 25 per minute, and blood pres- sure is 120/80 mm Hg. Physical examination reveals a mass in the right lower abdominal quadrant. At laparoscopy, there are numerous small bowel strictures and a fi stula extending into a loop of small bowel. Which of the following is the most likely diagnosis?

Q60453. A 30-year-old woman presents with 2 days of abdominal cramping and diarrhea. Her temperature is 38°C (101°F), respirations are 32 per minute, and blood pressure is 100/65 mm Hg. Stool culture shows a toxigenic Escherichia coli infection. Which of the following best explains the pathoge- nicity of this organism in this patient?

Q60454. A 1-year-old girl is brought to the emergency room by her par- ents who report that she had a fever and diarrhea for 3 days. The child’s temperature is 38°C (101°F). The CBC shows a normal WBC count and increased hematocrit. Which of the following microorganisms is the most likely cause of diarrhea in this young child?

Q60455. A 70-year-old man is rushed to the emergency room complain- ing of severe abdominal pain and rectal bleeding of 2 hours in duration. He has a history of coronary artery disease. Bowel sounds are absent on physical examination. A CT scan of the abdomen shows distention of the stomach and air-fl uid lev- els in the small bowel. Abdominal pain and bleeding in this patient most likely involved acute occlusion of which of the following arteries?

Q60456. The patient described in Question 39 is at increased risk of developing which of the following complications?

Q60457. A 44-year-old woman complains of having yellow eyes, dark urine, and recurrent fever for about 3 months. She has a long history of chronic diarrhea. On physical examination, the patient is thin and jaundiced. The liver edge descends 1 cm below the right costal margin and is nontender. Laboratory studies show elevated serum bilirubin of 3.8 mg/dL, nor- mal levels of AST and ALT, and an elevated level of alkaline phosphatase (440 U/dL). Endoscopic retrograde cholang- iopancreatography demonstrates a beaded appearance of the extrahepatic biliary tree. Which of the following is the most likely underlying cause of diarrhea in this patient?

Q60458. A 25-year-old woman is brought to the emergency room with symptoms of acute intestinal obstruction. The patient has an 8-month history of blood-tinged diarrhea and cramping abdom- inal pain. Her temperature is 38°C (101°F), and respirations are 32 per minute. There is abdominal tenderness to palpation. Lab- oratory studies show moderate anemia, with serum hemoglobin of 9.3 g/dL. Microscopic examination of the stool reveals numer- ous RBCs and WBCs. A CT scan of the abdomen shows massive distention of the transverse colon. Which of the following is the most likely underlying cause of this patient’s colonic disorder?

Q60459. A 74-year-old woman presents with 3 weeks of left lower quadrant abdominal pain, changes in bowel habits, and inter- mittent fever. Her temperature is 38°C (101°F), respirations are 19 per minute, and blood pressure is 130/80 mm Hg. Physical examination shows left lower quadrant tenderness. A CBC reveals neutrophilia. An abdominal-pelvic ultrasound examination is normal. Which of the following is the most likely diagnosis?

Q60460. A 9-year-old boy undergoes emergency surgery for presump- tive acute appendicitis. During the operation, the surgeon notices that the boy’s ileocecal lymph nodes are enlarged and matted together. One of the nodes is sent for a frozen section. The pathologist fi nds granulomatous infl ammation with cen- tral necrosis. The specimen is cultured. Which of the follow- ing pathogens is the most likely cause of lymphadenopathy in this patient?

Q60461. A 16-year-old girl complains of chronic abdominal distention, fl atulence, and diarrhea after drinking milk. Elimination of milk and other dairy products from the patient’s diet relieves these symptoms. This example of malabsorption is caused by a functional defi ciency of which of the following enzymes associated with the intestinal brush border membrane?