Follicle-stimulating hormone-secreting pituitary adenoma manifesting as recurrent ovarian cysts in a young woman – latent risk of unidentified ovarian hyperstimulation: a case report

BACKGROUND: Ovarian hyperstimulation caused by follicle-stimulating hormone-secreting gonadotroph cell adenoma is a rare, with a few reported cases, but almost certainly unnoticed cases occur because of the absence of detailed examinations. We retrospectively reviewed 200 patients treated for gonadotroph cell adenoma in our institute and identified 26 women of reproductive age. Two of these 26 patients had a history of ovarian cysts. One patient was considered to have had typical ovarian hyperstimulation, successfully treated by transsphenoidal surgery. The other patient initially underwent transsphenoidal surgery because of visual disturbance, but endocrinological examinations suggested possible relationships with previous ovarian hyperstimulation. We present the former case and discuss the latent risk of failure to identify this entity. CASE PRESENTATION: A 36-year-old woman with a sellar tumor was referred to our hospital with suspected ovarian hyperstimulation. She had a history of repeated surgery for ovarian cysts. Serum follicle-stimulating hormone and estradiol levels were within the normal ranges, and only the luteinizing hormone level was suppressed significantly. Transsphenoidal surgery achieved gross total tumor removal, and the histological diagnosis was follicle-stimulating hormone-secreting gonadotroph cell adenoma. The serum follicle-stimulating hormone, luteinizing hormone, and estradiol levels returned to the normal ranges postoperatively, and the ovarian cysts subsequently decreased in size without particular interventions. CONCLUSION: Ovarian hyperstimulation could regress after resolving the causes of high follicle-stimulating hormone level, so avoiding unnecessary ovary surgery. Detailed endocrinological examination including estradiol evaluation with pituitary imaging is quite important in women of reproductive age to establish the correct diagnosis.