Pituitary adenomas in acromegalic patients: an immunohistochemical and endocrinological study with special reference to prolactin-secreting adenoma.
To establish a functional classification of purification of pituitary adenomas in acromegalic patients, we used immunoperoxidase-staining techniques specific for GH and PRL. Surgical specimens from 55 acromegalic patients were studied. GH was demonstrated in all adenomas and PRL was found in 25 of them (45.5%). Immunohistologically, GH- and PRL-containing adenomas could be divided into 3 types. In type 1 (11 patients), immunoreactive PRL was present in single cells surrounded by immunoreactive GH cells. In type 2 (6 patients), immunoreactive PRL cells formed clusters. In Type 3 (8 patients), immunoreactive PRL and GH cells demonstrated a mosaic pattern, and it was difficult to determine which were in the majority. A double immunostaining method revealed 15 adenomas in which individual cells contained both GH and PRL. Hyperprolactinemia was present in 21 patients, 15 of these had immunoreactive PRL cells (type 1, 4 patients; type 2, 3 patients; type 3, 8 patients). There was no correlation between the size of the adenoma and its type. Endocrinologically, all patients with type 2 and 3 adenomas had an abnormal serum GH response to TRH administration; all type 3 patients had a substantial serum PRL response to TRH administration. Type 3 is considered to be an actively PRL-secreting adenoma, resulting in hyperprolactinemia.
D000172:Acromegaly / Q000378:metabolism*; D000236:Adenoma / Q000032:analysis* / Q000145:classification / Q000378:metabolism; D000328:Adult; D002648:Child; D005260:Female; D013006:Growth Hormone / Q000032:analysis*; D006651:Histocytochemistry; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000032:analysis* / Q000145:classification / Q000378:metabolism; D011388:Prolactin / Q000032:analysis* / Q000097:blood / Q000378:metabolism; D013973:Thyrotropin-Releasing Hormone
D013973:Thyrotropin-Releasing Hormone; D011388:Prolactin; D013006:Growth Hormone