Multiple endocrine neoplasia syndromes and somatotroph adenomas

Somatotroph adenomas can be associated with other endocrine tumors in the context of a multiple endocrine neoplasia (MEN) syndrome, specifically MEN type 1 (MEN1). This chapter provides an updated review of the history, epidemiology, clinical characteristics, and management of somatotroph adenomas in MEN1 and discusses the literature regarding pituitary neoplasia in MEN type 2 (MEN2). Growth hormone (GH)-secreting adenomas are not associated with MEN2 and are among the least common manifestations in MEN1. A significant number of these cases are not associated with a germline MEN1 mutation but instead are diagnosed in patients with clinical MEN1. Clinical presentation is comparable to sporadic acromegaly, and gigantism is rarely seen. Few data exist regarding the optimal therapy of GH excess in MEN1. More research may lead to a better understanding of MEN1-associated somatotroph tumors and differences between genotype-positive and genotype-negative cases. Contemporary approaches to screening in genotype-positive MEN1 patients should lead to an earlier diagnosis identifying smaller and less-invasive tumors.