The clinicopathological characteristics of gonadotroph cell adenoma: a study of 118 cases.

Gonadotroph cell adenoma was the most common pituitary adenoma, constituting 35% of the pituitary adenomas in our series of 339 patients with surgically removed pituitary adenomas from June 1987 to December 1995. The average age of these patients was 53 years, with a male predominance (1.5:1). The most common neurological symptoms were visual symptoms and headache. Amenorrhea and galactorrhea were recorded in 41% and 14%, respectively, of the female patients of reproductive age. Oncocytic change of varying degrees was seen in 69% of the tumors, and the average age of these patients (56 years) was older than those who had no such change (47 years) (P < .005). Five types of gonadotroph cell adenomas were recognized; they were tumors that contained (1) betaFSH, betaLH, and alphaSU, (2) betaFSH and betaLH, (3) betaFSH and alphaSU, (4) betaFSH, and (5) alphaSU. The immunostaining of betaFSH-containing cells was usually diffuse, whereas staining of betaLH- or alphaSU-containing cells was usually focal. Double immunostaining showed the immunoreactive cells containing one or any combination of the gonadotropin subunits. Increases in serum gonadotropin levels were only seen in 35% of the patients with gonadotroph cell adenoma. There was no correlation between serum hormonal levels and immunostaining results. Of the 33 recurrent cases, significant decrease or total absence of immunoreactivity of one or more hormone subunits in subsequent biopsy specimens were seen in three cases.