title: Gonadotroph adenoma in multiple endocrine neoplasia type 1.
abstract: OBJECTIVE
  To describe a case of an in vivo follicle-stimulating hormone (FSH)-secreting gonadotroph adenoma in a man with multiple endocrine neoplasia type 1 (MEN 1) syndrome.
  
  
  METHODS
  We present a retrospective case description and a discussion of the related literature.
  
  
  RESULTS
  A 48-year-old man had progressively deteriorating visual acuity and bitemporal hemianopia, found to be attributable to a macroadenoma encircling both carotid arteries and compressing the optic chiasm. His libido and erectile function had been reduced for 2 years. The serum FSH level was substantially elevated at 31.1 IU/L (reference range, 1 to 10); alpha-subunit was elevated at 2.25 IU/L (reference range, 0.09 to 0.4); luteinizing hormone was normal at 4 IU/L (reference range, 1 to 10); total testosterone was low at 6.8 nmol/L (reference range, 9.5 to 35); and prolactin was slightly increased at 433 mU/L (reference range, 50 to 300). Transsphenoidal hypophysectomy was performed. Pituitary histopathologic examination showed a tumor with cytoplasmic granular FSH immunoreactivity. The patient had undergone parathyroidectomy for primary hyperparathyroidism 2 years before the current intervention. A family history of endocrine neoplasia was obtained of one sibling with a nonfunctioning pituitary adenoma, another sibling who had died of pancreatic carcinoma, and a third sibling, along with her son, who has primary hyperparathyroidism. Performance of genetic testing for MEN 1 revealed a nonsense mutation--R460X (nt7605C>T)--located on exon 10 of the MEN1 gene.
  
  
  CONCLUSIONS
  We report an unusual case of clearly high circulating immunoreactive FSH due to a functioning FSH-secreting gonadotroph adenoma in a man with the MEN 1 syndrome.
authors.affiliation: Department of Endocrinology & Diabetes, The Alfred Hospital, Melbourne, Australia.
authors.forename: Shoshana
authors.initials: S
authors.lastname: Sztal-Mazer
authors.forename: Duncan J
authors.initials: DJ
authors.lastname: Topliss
authors.forename: Richard W
authors.initials: RW
authors.lastname: Simpson
authors.forename: P Shane
authors.initials: PS
authors.lastname: Hamblin
authors.forename: Jeffrey V
authors.initials: JV
authors.lastname: Rosenfeld
authors.forename: Catriona A
authors.initials: CA
authors.lastname: McLean