An extremely rare association of TSH-secreting pituitary adenoma, metastatic neuroendocrine tumor and Cushing’s syndrome in a patient with MEN-1 gene mutation

Abstract

Multiple endocrine neoplasia (MEN)-1 syndrome is a rare disorder, due to the loss of function of the tumor suppressor menin. It consists of the association of two or more endocrine tumors, often presenting in a familial setting, being inherited in an autosomal dominant fashion. The most frequent manifestations of MEN-1 syndrome are primary hyperparathyroidism, followed by pituitary adenomas (mainly prolactinomas) and gastrointestinal neuroendocrine tumors, but several other associated conditions have been reported. Herein we describe the case of a male patient, affected by sporadic MEN-1, diagnosed with primary hyperparathyroidism, TSH-secreting pituitary adenoma and bilateral adrenal hyperplasia causing Cushing’s syndrome, due to a de novo MEN-1 gene mutation. The patient has been successfully treated with first generation somatostatin analog Octreotide LAR (30 mg every 28 days) -with stabilization of the known neuroendocrine lesions and shrinkage of the pituitary adenoma- and with bilateral adrenalectomy. The patient is still regularly followed-up at our Endocrine Unit, and his clinical conditions are stable.