Octreotide reverses shock due to vasoactive intestinal peptide-secreting adrenal pheochromocytoma: A case report and review of literature.

Vasoactive intestinal peptide-producing tumors (VIPoma) usually originate in the pancreas and are characterized by diarrhea, hypokalemia, and achlorhydria (WDHA syndrome). In adults, nonpancreatic VIPoma is very rare. Herein, we report an unusual case of VIP-producing pheochromocytoma marked by persistent shock, flushing, and watery diarrhea and high sensitivity to octreotide. A 53-year-old woman was hospitalized for sudden-onset hypertension with convulsions, which then rapidly evolved to persistent shock, flushing, and watery diarrhea. Abdominal computed tomography indicated a left adrenal mass, accompanied by bleeding; and marked elevations of both plasma catecholamine and VIP concentrations were documented via laboratory testing. Surprisingly, all clinical symptoms responded swiftly to octreotide treatment. Once surgically treated, hormonal levels normalized in this patient, and the clinical symptoms dissipated. Postoperative pathological and immunohistopathological studies confirmed a VIP-secreting pheochromocytoma with strong, diffuse positivity for somatostatin receptor type 2. During a 6-mo follow-up period, she seemed in good health and was symptom-free.