Unusual manifestations of cushing's syndrome in a multiple endocrine neoplasia type I kindred.

Objective: To describe two unusual cases of Cushing's syndrome in a kindred with multiple endocrine neoplasia type I (MEN I).

Methods: The clinical and laboratory data as well as follow-up course of the two patients are reviewed in detail.

Results: Our first patient with a history of MEN I had hypercortisolism and computed tomographic evidence of a right adrenal mass (8.5 by 11 cm) extending into the inferior vena cava as well as multiple pulmonary nodules. He was diagnosed with Cushing's syndrome attributable to metastatic adrenal cancer that progressed despite chemotherapy. He died 2 years later. His son, who was also diagnosed with MEN I, had adrenocorticotropic hormone-dependent Cushing's syndrome. The plasma corticotropin-releasing hormone (CRH) level was high; magnetic resonance imaging showed normal pituitary findings but an islet cell tumor of the pancreas. The islet cell tumor was resected, and the patient's urinary cortisol declined to upper limits of normal. CRH was detected in the tissue, and the patient was thought to have Cushing's syndrome as a result of a CRH-secreting islet cell tumor. One year later, however, his Cushing's syndrome recurred. Inferior petrosal sinus sampling suggested a pituitary source, and the patient underwent transsphenoidal hypophysectomy. Histopathologic examination did not reveal pituitary hyperplasia or microadenoma, but the patient was cured of his Cushing's syndrome.

Conclusion: Cushing's syndrome is a rare initial manifestation of MEN I. We report two unusual causes of Cushing's syndrome in MEN I--that is, adrenal cancer and a probable CRH-secreting islet cell tumor. The natural history of Cushing's syndrome in MEN I is not known; further studies should be conducted.