Prolactinomas as part of the multiple endocrine neoplastic syndrome type 1.

The pituitary tumors seen in the multiple endocrine neoplastic syndrome type 1 have generally been considered "nonfunctional." Fewer than 40 persons with hyperprolactinemia as part of the syndrome have been described. A family with the largest number of subjects (six) with prolactinomas in one generation reported to date is described. The variable aggressiveness of this disease, the difficulty in treatment because of multiple prolactinomas or hyperplasia or both, and a case of tumor shrinkage with bromocriptine therapy are also demonstrated in this unique family.