[Immunohistochemical and clinicoendocrinological studies of gonadotropin producing pituitary adenomas]

In order to study the secretion of gonadotropins in clinically non-functioning pituitary adenomas, 83 cases were investigated by immunohistochemistry. Expression of one or more of gonadotropin subunits (alpha-subunit, follicle-stimulating hormone (FSH) beta, luteinizing hormone (LH) beta) was found in 38 (45.8%) of all adenomas studied. alpha subunit and FSH beta were positive in 28 (33.7%) and 27 (32.5%) cases respectively, whereas LH beta was detected in seven (8.4%) adenomas. The presence of both alpha subunit and FSH beta was found in 17 cases, while alpha subunit was singly positive in 11 cases and FSH beta, in 10 cases. LH beta was not detected alone, but was always accompanied by alpha subunit or FSH beta. By the double staining method, alpha subunit and FSH beta were not always colocalized in the same cells. Some cells were found to contain both alpha subunit and FSH beta, but others contained either alpha subunit or FSH beta. Clinical characteristics of gonadotropin positive adenomas (38 cases) were studied in comparison with null cell adenomas (37 cases), which were negative for all anterior pituitary hormones. The former (male 27, female 11) ranged in age from 21-74 years old (mean, 46.5 yr.), and the latter (male 16, female 21) from 28-68 yr (mean, 49.5 yr.). Gonadotropin positive adenomas tended to occur in middle-aged men. All 38 adenomas were macroadenomas, and 29 patients complained of visual failure. Clinical symptoms accompanied by hypersecretion of FSH was infrequent. Hypogonadism (amenorrhea, galactorrhea, loss of libido) were observed in 8 (9.6%) cases.(ABSTRACT TRUNCATED AT 250 WORDS)