A 42-year-old accountant is referred to your office for evaluation of progressive weight loss. He has lost 20 pounds over the last 6 months. He has a long history (16 years) of insulin-dependent diabetes mellitus. He denies alcohol abuse but admits to heavy smoking (2 packs of cigarettes per day for 20 years). Three days ago he noticed that his urine became dark and that his skin started to itch. He had a CT scan of the abdomen last week that revealed fullness in the head of the pancreas with dilatation of intra- and extrahepatic biliary ducts. The CT scan did not demonstrate a discrete mass in the pancreas or liver, gallstones, or pancreatitis. His physical examination is normal except for obvious jaundice. His blood work reveals WBC count 6.4, total bilirubin 5.7 mg/dL, alkaline phosphatase 340 U/L, amylase 64 U/L, and lipase 47 U/L. Which of the following tests would you order next?

Correct Answer: C

Rationale: The patient has developed obstructive jaundice. Obstructive jaundice and severe progressive weight loss in this young male with a long history of diabetes mellitus and heavy smoking could indicate a malignant neoplasm. Dilatation of both intra- and extrahepatic ducts, along with the fullness in the head of the pancreas, are suspicious for obstructing tumor in the head of the pancreas or in the major duodenal papilla (ampullary mass). The patient clinically does not have evidence of gastric outlet or duodenal obstruction (i.e., no nausea or vomiting), so an upper GI series is not indicated. Abdominal ultrasound and HIDA scan are unlikely to provide more information in this case. ERCP will allow visualization of the major duodenal papilla and reveal information about the biliary and pancreatic ducts (e.g., diameter, location, and grade of obstruction). ERCP can also relieve the obstruction with internal biliary stenting. If cannulation of the biliary ducts during the ERCP is not successful, then more invasive transcutaneous transhepatic cholangiography is indicated. This patient may also need endoscopic ultrasound with fine-needle aspiration biopsy to rule out an early, small mass in the head of the pancreas not detected by abdominal CT scan.

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.

Correct Answer: B

Rationale: Sucralfate forms a protective coating over ulcers, shielding them from acid and pepsin, thus aiding healing.