A case of malignant pheochromocytoma, with a recurrence 15 years after adrenalectomy and with an associated watery diarrhea, hypokalemia, achlorhydria syndrome, is reported. Histological evaluation of the tumors revealed composite malignant pheochromocytoma-ganglioneuroblastoma (well differentiated type). Vasoactive intestinal polypeptide and catecholamine levels were high both in the plasma and in the tumors. Somatostatin was also rich in the metastatic tumor of the liver, but not in the plasma. Immunohistochemical studies have demonstrated that immunoreactive vasoactive intestinal polypeptide is present in the ganglioneuroblastoma component, and that immunoreactive somatostatin is present in the pheochromocytoma component. Literature on the watery diarrhea, hypokalemia, achlorhydria syndrome associated with pheochromocytoma was reviewed.
