A case of recurrent malignant pheochromocytoma complicated by watery diarrhea, hypokalemia, achlorhydria syndrome.

A patient is reported who had undergone right adrenalectomy for pheochromocytoma and 15 yr later developed a recurrence in the same site complicated by the watery diarrhea, hypokalemia, achlorhydria syndrome. This tumor was histologically defined as a composite malignant pheochromocytoma-ganglioneuroblastoma (well differentiated type). Vasoactive intestinal polypeptide and catecholamine concentrations were elevated in both plasma and the tumor. The tumor somatostatin content also was high. The tumor was immunohistochemically determined to contain both vasoactive intestinal polypeptide and somatostatin.