Endocrine Abstracts

Gonadotroph pituitary adenomas are common but majority of them are classified as non-functional as they do not lead to features of hormonal excess. Functional gonadotroph adenomas are rare and there are only few small series or individual case reports about these.

Case report: 45-year-old gentleman presented with headaches, progressive visual failure and complaint of excessive tiredness. He had normal libido and had an 8-year-old child. On examination, he had bitemporal hemianopia and bilaterally enlarged testes (>40 ml bilaterally). His MRI showed a large pituitary macroadenoma (35×29×26 mm) with suprasellar extension and displacing the optic chiasma. His blood results showed high normal haemoglobin of 180 g/l (130–180) with borderline high haematocrit of 0.51 l/l (0.40–0.50). Sex hormone profile was as follows: LH: 10.5 IU/l (3.0–13); FSH: 15.7 IU/l (1.3–9.2); Testosterone: 43.4 nmol/l (9–25); free Testosterone 1257 pmol/l (215–760); Sex Hormone Binding Globulin 26 nmol/l (15–48). Alpha sub-unit was also elevated at 2.55 IU/l (NR<1.0). His thyroid functions were as follows: TSH: 7.61 mU/l (0.3–4.7), FT₄: 6.0 pmol/l (9.5–21.5); FT₃: 2.7 pmol/l (3.5–6.5). Prolactin was mildly high at 982 mIU/l (0–450). GH and IGF1 were normal at 0.13 μg/l and 14 nmol/l (7–28) respectively. His baseline cortisol was low at 75 nmol/l. He was started on Dexamethasone and Levothyroxine and underwent trans-sphenoidal pituitary adenomectomy. He made an uneventful recovery apart from transient diabetes insipidus. The histology was consistent with pituitary adenoma with scattered FSH positive cells and very rare LH positive cell. In the post-operative period, his LH, FSH & Testosterone levels were 0.7 IU/l, 3.0 IU/l and <1.0 nmol/l respectively. His visual fields also improved significantly. He is continuing on steroids and levothyroxine. The patients reported earlier had either high testosterone levels or testicular enlargement. The authors could not find any case report of a patient with both, high testosterone level and testicular enlargement, secondary to functional gonadotrophinoma.