Review Question - QID 213377

A 40-year-old man presents to the emergency department for abdominal pain. The patient states that he has had abdominal pain for a while, but it became unbearable today and he is concerned. He also endorses a weight loss of 20 pounds this past month and complains of bulky and foul-smelling stools. The patient is homeless and is currently living by a local wash where he obtains his drinking water and cleans his clothes. He admits to recently eating raw meat that he found. The patient has a past medical history of alcohol abuse, malnutrition, Wernicke-Korsakoff psychosis, IV drug use, and a recent hospitalization for intoxication of unknown etiology. The patient is not taking any medications currently. His temperature is 99.1°F (37.3°C), blood pressure is 100/67 mmHg, pulse is 120/min, respirations are 11/min, and oxygen saturation is 98% on room air. On physical exam, the patient complains of epigastric tenderness. Cardiopulmonary exam is within normal limits. The patient is started on IV fluids, thiamine, folate, magnesium, and dextrose. Laboratory values are ordered as seen below:

Hemoglobin: 9.0 g/dL
Hematocrit: 25%
Leukocyte count: 5,500 cells/mm^3 with normal differential
Platelet count: 222,000/mm^3

Serum:
Na+: 137 mEq/L
Cl-: 102 mEq/L
K+: 4.1 mEq/L
HCO3-: 24 mEq/L
BUN: 24 mg/dL
Glucose: 68 mg/dL
Creatinine: 1.4 mg/dL
Ca2+: 9.8 mg/dL
Amylase: 22 U/L
Lipase: 22 U/L
Aspartate aminotransferase (AST): 58 U/L
Alanine aminotransferase (ALT): 18 U/L

A computed tomography (CT) scan is obtained as seen in Figure A. What is the most likely diagnosis?