Parathyroid carcinoma in multiple endocrine neoplasia type 1. Case report and review of the literature.

Parathyroid carcinoma is an infrequent cause of primary hyperparathyroidism. Although hyperparathyroidism in multiple endocrine neoplasia 1 (MEN1) syndrome is the most common manifestation, parathyroid carcinoma is rare. We report a male patient who was diagnosed at 44 years of age with parathyroid carcinoma in the context of MEN1 syndrome coincident with a malignant gastrinoma and non-functioning adrenal adenomas. A genetic analysis revealed the mutation W183C in exon 3 of the MEN1 gene. The diagnosis of carcinoma was made after parathyroid surgery; there had been no clinical suspicion prior to surgery, as the patient had presented only moderate hypercalcemia. Our review of the few published cases of parathyroid carcinoma in MEN1 syndrome reported in the literature indicates that MEN1 gene mutations do not confer a greater risk for parathyroid carcinoma and do not appear to differ from sporadic parathyroid carcinoma.