Malignant nonfunctioning pheochromocytoma occurring in a mixed multiple endocrine neoplasia syndrome.

OBJECTIVE

To present the first documented case of malignant nonfunctioning pheochromocytoma occurring in a mixed multiple endocrine neoplasia (MEN) syndrome.

METHODS

We describe the personal and family history of a 34-year-old man with headaches, increased serum prolactin levels, and hyperparathyroidism and review the details of his clinical course and treatment.

RESULTS

After diagnosis of a prolactinoma, bromocriptine therapy was implemented but eventually discontinued by the patient when severe headaches recurred. A transsphenoidal resection of a prolactinoma was performed; the patient continued to have abnormally high serum prolactin levels. Subsequent left lower flank pain prompted an exploratory laparotomy, and a left nephroad-renalectomy was performed. Pathologic examination disclosed a 1-cm tumor, consistent with malignant pheochromocytoma. Electron microscopy demonstrated neurosecretory granules. A hypercoagulable state complicated the course postoperatively. Despite chemotherapy, extensive metastatic disease ensued, and the patient died.

CONCLUSIONS

Although pheochromocytomas are usually associated with MEN type IIA and type IIB, this patient had a malignant pheochromocytoma, without the usual clinical and biochemical manifestations, in the setting of MEN type I.