title: Pathological study of thyrotropin-secreting pituitary adenoma: plurihormonality and medical treatment.
abstract: Thyrotropin (TSH)-secreting adenomas are rare and, as most adenomas are large, invasive and difficult to cure by surgery only, many require additional medical treatment. Many TSH-secreting adenomas cosecrete growth hormone (GH) and/or prolactin (PRL). We evaluated the relationship between pathology and the effect of dopamine agonist bromocriptine and somatostatin analogue octreotide in 20 operated patients with TSH-secreting adenomas. The four men and 16 women ranged in age from 23 to 62 years; three had clinically overt acromegaly; two manifested galactorrhea-amenorrhea. Endocrinologically, elevated serum GH, and/or IGF-1 were observed in six patients and elevated serum PRL was observed in eight. Immunohistochemically, 16 of the 20 adenomas were positive for GH and/or PRL (GH-positive, n=13; PRL-positive, n=9). Pituitary-specific transcription factor Pit-1 was demonstrated in the nuclei of all adenoma cells. Octreotide tests showed suppression of serum TSH (<50%) in ten of 14 patients. Preoperative octreotide treatment effectively reduced serum TSH and tumor size in two patients. Electron micrographs of octreotide-treated TSH-secreting adenomas showed shrinkage of the cytoplasm and diffuse distribution of secretory granules. Our study suggests that cosecretion of GH and/or PRL from TSH-secreting adenoma has no correlation with response of tumor cells to medical treatment.
authors.affiliation: Department of Neurosurgery, Nippon Medical School, 1-1-5 Sendagi Bunkyo-ku, 113-8603 Tokyo, Japan. a-tera@nms.ac.jp
authors.forename: Akira
authors.initials: A
authors.lastname: Teramoto
authors.forename: Naoko
authors.initials: N
authors.lastname: Sanno
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Tahara
authors.forename: Yoshiyuki R
authors.initials: YR
authors.lastname: Osamura
mesh_terms: D000236:Adenoma / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D000328:Adult; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use*; D001971:Bromocriptine / Q000627:therapeutic use; D005260:Female; D013006:Growth Hormone / Q000097:blood; D006727:Hormone Antagonists / Q000627:therapeutic use; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008297:Male; D008854:Microscopy, Electron / Q000379:methods; D008875:Middle Aged; D015282:Octreotide / Q000627:therapeutic use; D010911:Pituitary Neoplasms / Q000188:drug therapy / Q000378:metabolism / Q000473:pathology* / Q000648:ultrastructure; D011388:Prolactin / Q000097:blood; D012189:Retrospective Studies; D013194:Staining and Labeling; D013972:Thyrotropin / Q000378:metabolism*
chemical_list: D018931:Antineoplastic Agents, Hormonal; D006727:Hormone Antagonists; D001971:Bromocriptine; D011388:Prolactin; D013972:Thyrotropin; D013006:Growth Hormone; D015282:Octreotide