MEN1 clinical background.

Multiple endocrine neoplasia Type 1 (MEN1) is a rare hereditary tumor syndrome predisposing to tumor development in several endocrine organs. Its major manifestations include hyperparathyroidism, tumors of endocrine pancreas and pituitary. Beside these three, several other endocrine (adrenocortical, foregut carcinoid) and nonendocrine (lipoma, angiofibroma, collagenoma, ependymoma, meningioma) tumors have been described to be associated with this syndrome. Both familial and sporadic forms of the disease are known. The diagnosis of MEN1 can be established if two of the three major manifestations are found in the same patient, whereas the diagnosis of familial MEN1 requires one MEN1 patient and a first degree relative with at least one MEN1 manifestation. MEN1 is transmitted as an autosomal dominant trait with high penetrance, approaching 95-100% by the age of 60. Both benign (parathyroid, anterior pituitary) and malignant (gastrinoma, glucagonoma) lesions may develop in MEN1 patients. Regular surveillance of MEN1 gene mutation carriers is necessary to reveal disease manifestations. Several diagnostic modalities can be used to screen for and to examine MEN1-related tumors. The therapy of MEN1-associated tumors requires specific approach in some cases, as multiple tumors and recurrence is frequently observed.