A patient with thyrotropinoma cosecreting growth hormone and follicle-stimulating hormone with low alpha-glycoprotein: a new subentity?
BACKGROUND
Thyrotropinomas are rare pituitary tumors. In 25 percent of cases there is autonomous secretion of a second pituitary hormone, adding to the clinical complexity. We report a patient with thyrotropin (TSH)-dependant hyperthyroidism along with growth hormone (GH) and follicle-stimulating hormone (FSH) hypersecretion but low alpha-glycoprotein (alpha-subunit) concentrations, a hitherto unique constellation of findings.


CONCLUSIONS
A 67-year-old Scottish lady presented with longstanding ankle edema, paroxysmal atrial fibrillation, uncontrolled hypertension, fine tremors, warm peripheries, and agitation. Initial findings were a small goiter, elevated serum TSH of 7.37 mU/L (normal range, 0.30-6.0 mU/L), a free-thyroxine concentration of 34.9 pmol/L (normal range, 9.0-24.0 pmol/L), a flat TSH response to TSH-releasing hormone, and serum alpha-subunit of 3.1 IU/L (normal, <3.0 IU/L). There was no evidence of an abnormal thyroid hormone beta receptor by genotyping. Serum FSH was 56.8 U/L, but the luteinizing hormone (LH) was 23.6 U/L (postmenopausal FSH and LH reference ranges both >30 U/L) Basal insulin-like growth factor I was elevated to 487 microg/L with the concomitant serum GH being 14.1 mU/L, and subsequent serum GH values 30 minutes after 75 g oral glucose being 19.1 mU/L and 150 minutes later being 13.7 mU/L. An magnetic resonance imaging pituitary revealed a macroadenoma. Pituitary adenomectomy was performed with the histology confirming a pituitary adenoma, and the immunohistochemistry staining showed positive reactivity for FSH with scattered cells staining for GH and TSH. Staining for other anterior pituitary hormones was negative. After pituitary surgery she became clinically and biochemically euthyroid, the serum IFG-1 became normal, but the pattern of serum FSH and LH did not change.


CONCLUSIONS
This case of plurihormonal thyrotropinoma is unique in having hypersecretion of TSH, GH, and FSH with low alpha-subunit. Such a combination may represent a new subentity of TSHomas.
Elhadd
Tarik A
TA
Department of Medicine and Endocrinology, Diabetes Centre, Ayr Hospital, United Kingdom. tarikelhadd58@gmail.com
Ghosh
Sujoy
S
Teoh
Wei Leng
WL
Trevethick
Katy Ann
KA
Hanzely
Zoltan
Z
Dunn
Laurence T
LT
Malik
Iqbal A
IA
Collier
Andrew
A
D000368:Aged; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism*; D005838:Genotype; D006023:Glycoproteins / Q000378:metabolism*; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D013006:Growth Hormone / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008279:Magnetic Resonance Imaging / Q000379:methods; D008954:Models, Biological; D010902:Pituitary Gland / Q000473:pathology; D010911:Pituitary Neoplasms / Q000145:classification / Q000378:metabolism* / Q000473:pathology; D013972:Thyrotropin / Q000378:metabolism
D006023:Glycoproteins; D007987:Gonadotropin-Releasing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin; D013006:Growth Hormone