Clinical presentation of PCOS following development of an insulinoma: case report

Abstract

A 24 year old woman presented with a prolonged clinical history of fasting and exertional hypoglycaemia, and was subsequently diagnosed with an insulinoma. Concurrent symptoms of oligomenorrhoea and hyperandrogenism of similar duration were noted. Biochemically, hyperinsulinaemia was observed in association with a raised serum luteinizing hormone (LH), raised testosterone and androstendione concentrations. Surgical removal of the insulinoma resulted in resolution of the clinical and biochemical features of the polycystic ovarian syndrome (PCOS) but minimal change was observed in the ovarian ultrasound appearances. This case demonstrates the role of insulin in mediating the hypersecretion of both LH and androgens in women with polycystic ovaries. We suggest that hyperinsulinaemia converted occult 'polycystic ovaries' to become clinically manifest as 'polycystic ovary syndrome'. This paradigm has clear implications for women with insulin dependent diabetes mellitus who presumably have systemic hyperinsulinaemia.