Atypical clinical manifestations of multiple endocrine neoplasia type 1 syndrome.

Multiple endocrine neoplasia type 1 (MEN1) is a hereditary tumor syndrome characterized by a genetic predisposition to develop a variety of neuroendocrine tumors and hormone excess syndromes. The major components of MEN1 are hyperparathyroidism due to multiple parathyroid adenomas or hyperplasia, duodenopancreatic neuroendocrine tumors and pituitary adenomas, most often producing prolactin. Physicians' inadequate knowledge of this clinical entity and sometimes its atypical presentation result in a probable significant underdiagnosis of MEN1. This describes the case of a 65-year-old female in whom primary hyperparathyroidism, limited to only one parathyroid gland, was preceded by acromegaly that was diagnosed 23 years earlier. This case shows that MEN1 manifests itself even in older groups and hyperparathyroidism may not be the first symptom of this syndrome. Therefore, we believe that all subjects who, regardless of age, gender and initial manifestation present with whichever the major symptom should be followed up regularly for the early detection of MEN1.