Ectopic Hormone-Secreting Pheochromocytoma: A Francophone Observational Study

Ectopic hormone-secreting pheochromocytomas are rare; only case reports exist in the literature. This condition has been linked with increased malignancy, familial syndromes, and ACTH secretion. We wanted to test these hypotheses and shed light on the nature of ectopic hormone-secreting pheochromocytomas. This is a multicenter (francophone) observational study. Inclusion was based upon abnormal preoperative hormone tests in patients with pheochromocytoma that normalized after removal of the tumor. Where possible, immunohistochemistry was performed to confirm that ectopic secretion came from the tumor. Sixteen cases were found: nine female and seven male patients. Median age was 50.5 (range 31-89) years. Most presented with hypertension, diabetes, or cushingoid features. Ten patients had specific symptoms from the ectopic hormone secretion. Two had a familial syndrome. Of eight patients with excess cortisol secretion, three died as a result of the tumor resection: two had pheochromocytomas > 15 cm and their associated cortisol hypersecretion complicated their postoperative course. The other died from a torn subhepatic vein. The 13 survivors did not develop any evidence of malignancy during follow-up (median 50 months). Symptoms from the ectopic secretion resolved after removal of the tumor. Immunohistochemistry was performed and was positive in eight tumors: five ACTH, three calcitonins, and one VIP. Most pheochromocytomas with ectopic secretion are neither malignant nor familial. Most ectopic hormone-secreting pheochromocytoma cause hypercortisolemia. Patients with a pheochromocytoma should be worked up for ectopic hormones, because removal of the pheochromocytoma resolves those symptoms. Associated cortisol secretion needs careful attention.