Functioning gonadotrophin-secreting pituitary adenomas are rare. These benign tumours are difficult to diagnose, due to their insidious onset and slow growth, and are often misdiagnosed as polycystic ovary syndrome in women and as sexual dysfunction in men.

Noor et al. report a case of a 42-year-old father who presented with COVID-19 and a historical brain mass which had been found on a trauma computed tomography scan 12 years earlier. He had long-standing dizziness and vision impairment (right eye) that were never investigated. On examination, he had bilaterally enlarged testicles (>25cm³) and a left monocular temporal defect. Blood tests showed raised luteinising hormone (6.4IU/l), follicle-stimulating hormone (FSH; 31.4IU/l) and testosterone (50.31nmol/l) as well as hypothyroidism (thyrotrophin 3.54mIU/l, free thyroxine 6.6pmol/l). A 09.00am cortisol measurement was normal (274nmol/l). Pituitary magnetic resonance imaging confirmed a 30×23×22mm expanding mass in the pituitary fossa extending to the suprasellar cistern.

He started levothyroxine and hydrocortisone preoperatively. Transsphenoidal surgery was successful (histology confirmed an FSH-positive gonadotrophin-secreting adenoma). Testicular size (17.9–21.1cm³) and hormonal abnormalities normalised postoperatively.

This case highlights the difficulty of diagnosing functioning gonadotrophin-secreting pituitary adenomas and the importance of reviewing historic brain imaging.

Read the full article in Endocrinology, Diabetes & Metabolism Case Reports EDM-22-0322 https://doi.org/10.1530/EDM-22-0322