Endocrine Abstracts

Introduction: We present the case of a clinically functioning gonadotroph adenoma in a pre-menopausal woman with abdominal pain, bilateral multi-cystic ovaries and fibromatosis. To our knowledge, this is the first case of fibromatosis associated with a functioning gonadotroph adenoma.

Case: A 36 year old female presented on three occasions with acute abdominal pain. She was previously well and had two normal pregnancies. On the first admission, she underwent bilateral cystectomy for large benign follicular cysts. On the second admission she required a right oophorectomy and salpingectomy for ovarian torsion and left ovarian cyst aspiration. On her third presentation she required resection of a 4×1.7 cm rectus abdominis muscle mass. Histology confirmed fibromatosis (desmoid tumour). On review in the endocrine clinic, she reported persistent abdominal pain, slightly less regular periods, no galactorrhoea and no headaches. Examination was unremarkable. Endocrine investigations showed an elevated oestradiol, FSH at the upper limit of normal and a suppressed LH. Prolactin was mildly elevated. All other pituitary function tests were normal. Pituitary MRI revealed a 1.5 cm pituitary macroadenoma, with no evidence of chiasmatic compression. A diagnosis of an FSH secreting pituitary adenoma was made and she underwent transphenoidal hypophysectomy. Histology confirmed a pituitary adenoma with FSH immunopositivity in keeping with gonadotroph cell adenoma. Post operatively, her abdominal pain resolved and she resumed a normal menstrual cycle. Her oestradiol, FSH and LH levels normalised. Pelvic ultrasound showed two normal follicles 2–3 cm in size. Post-operative MRI at three months showed removal of the majority of the pituitary adenoma with a small residuum within the right cavernous sinus.

Discussion: Gonadotroph adenomas are usually clinically non-functioning, but rarely can cause clinical symptoms. This case highlights the importance of considering the diagnosis of a functioning gonadotroph adenoma in patients presenting with recurrent, large follicular cysts and fibromatosis.