Endocrine Abstracts

A 40-year-old woman, who had developed oligomenorrhoea after discontinuing the contraceptive pill at age 30, presented with a 6-month history of intermittent vomiting associated with abdominal discomfort and distension. Ultrasound, followed by laparotomy, revealed multiple bilateral ovarian luteal cysts consistent with hyperoestrogenism and ovarian-hyperfunctioning.

Only 9 months post-operatively her bilateral theca ovarian cysts had recurred. Over 4 months monitoring her estrogen levels fluctuated between 9923, 20 616 and 18 506 pmol/l (110–850) with FSH levels of 9.5–9.6 IU/l (1–9) and LH levels of 1.9–2 IU/l (4–10). Tumour markers HCG, CEA and AFP were not elevated. Inhibin-B levels (67 pg/ml (>45)) and thyroid and adrenal function were normal. α-Subunit and 17-OHP were slightly raised at 1.4 IU/l (<1) and 29.2 nmol/l (10–20 luteal) respectively. MRI scanning revealed a 10×14×17 mm pituitary macroadenoma displacing the optic chiasm (visual fields were full to confrontation).

A microsurgical, transnasal selective adenectomy was performed 18 months after her original presentation. Histology demonstrated a largely endocrinologically inactive pituitary adenoma with scattered FSH and occasional LH and ACTH immunopositive cells. Prolactin levels of 2480 and 2970 mIU/l, 7 and 4 months preoperatively, fell to an average of 203 mIU/l post-operatively. Mild diabetes insipidus and hypoadrenalcorticalism resolved spontaneously within 6 weeks of surgery leaving her with no exogenous pituitary hormone requirements. Random oestradiol levels measured 1, 4 and 9 months post-operatively were 182, 1503 and 362 pmol/l (110–850) respectively. She resumed menstruating spontaneously and a trans-vaginal ultrasound performed 5 months post-operatively showed no recurrence of ovarian cystic disease.

Despite persistently normal pre-operative gonadotrophin levels and the subsequent finding of relatively sparse gonadotrophs on pituitary adenoma histology, complete resolution of ovarian-hyperfunctioning suggests that a functional pituitary gonadotrophinoma – large enough to cause modest pituitary stalk compression and hyperprolactinaemia – was the cause of this patient’s problem.