Macro- and microadenoma of thyrotropin secreting pituitary tumors--two clinical cases.
Thyrotropin secreting adenoma, thyrotropinoma (TSH-oma), is a rare cause of hyperthyroidism--called secondary hyperthyroidism. The hormonal profile in pituitary hyperthyroidism is characterized by a nonsuppressed TSH in the presence of high levels of free thyroid hormones (fT4, fT3) reflecting an abnormal feedback. The diagnosis of TSH-oma is often made at the stage of macroadenoma because of the aggressive nature of the tumor and due to the fact that patients are mistakenly treated for more common primary hyperthyroidism for a long time. Two cases of TSH-secreting adenoma were detected in Chair and Department of Endocrinology, Collegium Medicum of the Jagiellonian University in Krakow for the last twenty years. Case 1: 49 year old woman was admitted to the Clinic of Endocrinology in 1999 with recurring hyperthyroidism treated with surgical thyroid ablation in 1992 and thyreostatics for the previous nine years. On admission to the Clinic her thyroid panel presented with elevated free hormone levels (mainly fT3-14.8 pmol/l) and not suppressed TSH-0.7 mIU/l suggesting central hyperthyroidism. MRI scan of the pituitary gland revealed microadenoma of 5 mm in diameter. She was qualified to transsphenoidal resection of the tumor. Histopathology revealed acidophilic adenoma with positive TSH staining. Thyroid hormones 8 days after the operation suggested full effectiveness of the surgery. Case 2: 65 year old man treated for one year with L-Thyroxin because of elevated TSH (60 mIU/l) and then with thyreostatics for elevated fT3 and fT4 was admitted to the Clinic of Endocrinology in 2000 with suspected thyrotropinoma. On admission to the Clinic thyroid panel suggested hyperthyroidism with fT4-40 pmol/l, FT3-11.2 pmol/l without suppression of TSH 2.2 mIU/l. MRI scan revealed a pituitary tumor 20 x 18 x 20 mm, compressing the optic chiasm. He was administered octreotide as a preparation for the operation. The patient underwent trans-sphenoidal resection of the adenoma (histopathologically a chromophobic adenoma). The example of presented patients suggests that clinical course of the pituitary tumor producing TSH and the rate of the tumor growth may differ significantly. Surgical resection of TSH producing adenoma is the most effective therapy. It should be proceeded by octreotide administration in patients with macroadenoma.
Hubalewska-Hola
Alicja
A
Department of Endocrinology, Collegium Medicum of Jagiellonian University, 17 Kopernika Str., 31-501 Krakow, Poland. alahuh@endo.cm-uj.krakow.pl
Fröss
Katarzyna
K
Kostecka-Matyja
Marta
M
Sowa-Staszczak
Anna
A
Szybiński
Zbigniew
Z
Huszno
Bohdan
B
Ptak
Marzena
M
D000236:Adenoma / Q000378:metabolism*; D000368:Aged; D005260:Female; D006801:Humans; D006980:Hyperthyroidism / Q000097:blood / Q000209:etiology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010911:Pituitary Neoplasms / Q000378:metabolism*; D013972:Thyrotropin / Q000097:blood / Q000378:metabolism*
D013972:Thyrotropin