Cushing's syndrome in multiple endocrine neoplasia type 1

Objective In patients with multiple endocrine neoplasia type 1 (MEN1), Cushing’s syndrome (CS) from endogenous hypercortisolism can result from pituitary, adrenal or other endocrine tumours. The purpose of this study was to characterize the range of presentations of CS in a large series of MEN1 patients. Design Retrospective review of NIH Clinical Center inpatient records over an approximately 40‐year period. Patients Nineteen patients (eight males, 11 females) with CS and MEN1. Measurements Biochemical, imaging, surgical and pathological findings. Results An aetiology was determined for 14 of the 19 patients with CS and MEN1: 11 (79%) had Cushing’s disease (CD) and three (21%) had ACTH‐independent CS owing to adrenal tumours, frequencies indistinguishable from sporadic CS. Three of 11 MEN1 patients with CD (27%) had additional non‐ACTH‐secreting pituitary microadenomas identified at surgery, an incidence 10‐fold higher than in sporadic CD. Ninety‐one per cent of MEN1 patients with CD were cured after surgery. Two of three MEN1 patients with ACTH‐independent CS (67%) had adrenocortical carcinoma. One patient with adrenal cancer and another with adrenal adenoma were cured by unilateral adrenalectomy. No case of ectopic ACTH secretion was identified in our patient cohort. The aetiology of CS could not be defined in five patients; in three of these, hypercortisolism appeared to resolve spontaneously. Conclusions The tumour multiplicity of MEN1 can be reflected in the anterior pituitary, MEN1‐associated ACTH‐independent CS may be associated with aggressive adrenocortical disease and an aetiology for CS in MEN1 may be elusive in a substantial minority of patients.