A 65-year-old white female with a history of arthritis, congestive heart failure, and osteoporosis complains of odynophagia for two weeks. A barium swallow shows a moderate-sized crater just above the gastroesophageal junction. What is the least likely contributor to this condition?

Correct Answer: D

Rationale: All of the other medications have been associated with pill-induced esophagitis. Pill-induced esophagitis is usually associated with the failure to ingest at least 8 ounces of water with the medication while upright and, less commonly, an underlying motility disorder. Resolution of pill-induced esophagitis and ulceration occurs rapidly once the offending medication is discontinued. Acid suppressive therapy is usually prescribed to prevent reflux-related injury.

Correct Answer: D

Rationale: This young man with weight loss, malodorous, bulky stools, increased appetite, and iron deficiency anemia has celiac disease as the most likely diagnosis. Patients occasionally may feel constipated; however, the stools are unusually bulky and consistently malodorous. The disease is diagnosed by biopsy of the small bowel by upper endoscopy (Answer A). Elevated anti-endomysial antibodies are highly suggestive. Fat malabsorption can be rigorously established by fecal fat collection. The differential diagnosis includes chronic pancreatitis, which is best evaluated by CT scan. A colonoscopy is helpful to evaluate iron deficiency anemia to rule out colonic tumors or other causes of occult blood loss or to assess for inflammatory bowel disease. However, in this patient with malabsorption, increased appetite, and young age, sprue is more likely to explain the constipation and iron deficiency anemia. He does not have abdominal pain, blood in the stools, or diarrhea, the most common symptoms of inflammatory bowel disease. Colonoscopy will be less useful.

Correct Answer: D

Rationale: This man presents with the hallmarks of Whipple's disease (i.e., abdominal pain, diarrhea, weight loss, and arthralgias). His workup has made the diagnoses of thyroid disease, HIV, inflammatory bowel disease, and collagen vascular diseases unlikely. His small bowel biopsy is consistent with changes seen in Whipple's disease. Electron microscopy of the specimen should be able to identify the Whipple bacillus. In contrast, the pathologic findings in celiac disease include decreased villous height to crypt depth, decreased epithelial surface cell height, and increased lymphocytic infiltration of the mucosa. PAS-positive material in the lamina propria is not seen. The treatment for Whipple's disease is one year of trimethoprim/sulfamethoxazole. A gluten-free diet would be used for celiac disease. A lactose-free diet is indicated for patients with lactose intolerance. Cholestyramine is used for patients with bile acid diarrhea, usually in the setting of ileal disease. Prednisone can be used in some cases of inflammatory bowel disease and refractory celiac sprue but is not appropriate for Whipple's.

Correct Answer: B

Rationale: Hepatomegaly, portal vein thrombosis, or new ascites in someone with chronic hepatitis B is hepatocellular carcinoma until proven otherwise. Replication flares do not typically present with pain or hepatomegaly.

Correct Answer: A

Rationale: Helicobacter pylori infection is the most common cause of PUD, as it damages the protective mucosal lining of the stomach and duodenum, leading to ulcer formation.