A woman in her early 50s with a history of polycystic ovarian syndrome, diabetes, stroke, and coronary artery disease that required coronary artery bypass graft 6 years earlier presented to the emergency department with 12 hours of sudden-onset, constant, right lower quadrant abdominal pain associated with vomiting and melena. She denied any hematochezia or history of peptic ulcer disease. She had no other surgical history and denied alcohol use or smoking. On examination, she was hypertensive (blood pressure, 185/85 mm Hg) although not tachycardic and was afebrile. She was locally tender to palpation in the right lower quadrant with rebound and voluntary guarding. Her abdomen was not tympanitic. The patient had no abdominal scars, hernias, or palpable masses. Laboratory results were significant for the following: leukocyte count, 23 600/µL (to convert to ×109/L, multiply by 0.001) with neutrophilia (94%); blood urea nitrogen level, 28 mg/dL (to convert to millimoles per liter, multiply by 0.357); creatinine concentration, 0.01 mg/dL (to convert to micromoles per liter, multiply by 88.4); lipase concentration, 195 U/L (to convert to microkatals per liter, multiply by 0.0167); and lactate concentration, 2.02 mg/dL (to convert to millimoles per liter, multiply by 0.111). Electrolyte levels and liver function test results were within normal limits. An electrocardiogram showed normal sinus rhythm. Computed tomography of the abdomen and pelvis with oral and intravenous contrast enhancement was performed (Figure).