VIPoma

Case history

A 59-year-old woman presents with a 3-month history of profuse watery diarrhea, weakness, and dehydration. Examination reveals poor skin turgor. Blood test results show severe hypokalemia (2.1 mEq/L), hypercalcemia (11.2 mg/dL), low bicarbonate (17 mEq/L), and metabolic acidosis (pH 7.26).