A Patient with Thyrotropinoma Cosecreting Growth Hormone and Follicle-Stimulating Hormone with Low α-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 α-glycoprotein (α-subunit) concentrations, a hitherto unique constellation of findings. Summary: 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 α-subunit of 3.1 IU/L (normal, <3.0 IU/L). There was no evidence of an abnormal thyroid hormone β receptor by genotyping. Serum FSH was 56.8 U/L, but the luteinizing hormone (L...