THU618 Adrenal Cell Carcinoma Presenting With Post-menopausal Bleeding And IGF-2 Induced Hypoglycaemia

Disclosure: E.M. Lonergan: None. L.J. Tan: None. E. Ali: None. C.M. Joyce: None. N. Conlon: None. A. O'Sullivan: None. D.J. O'Halloran: None. Background: Non-islet cell tumour hypoglycaemia (NICTH) as a result of IGF-2 secretion is rare with a few case reports associated with adrenal tumours. Clinical Case: We present the case of a 59-year-old female initially presenting to gynaecology services with post-menopausal bleeding due to endometrial hyperplasia. Serum testosterone, oestradiol and adrenal androgens were found to be elevated and LH and FSH suppressed. A subsequent CT adrenals demonstrated a 12.8 x 13.2 x 10.6cm left adrenal mass and she failed a 1mg overnight dexamethasone suppression test. In the interim, while undergoing evaluation, the patient presented to A+E Department with point-of-care confirmed hypoglycaemia with a capillary blood glucose of 1.6mmol/L and neuroglycopaenic symptoms. There was no history of diabetes mellitus, prolonged fasting, access to sulphonylureas or insulin. During a supervised fast, symptomatic hypoglycaemia occurred within 5 hours at 2.0mmol/L fulfilling Whipple’s triad. Results of samples taken during hypoglycaemia revealed an elevated IGF-2 : IGF-1 ratio of 60.7 (normal <10) with a low paired C-peptide, insulin and pro-insulin, consistent with a suspected IGF-2-secreting tumour. Hypoglycaemia was successfully managed with low glycaemic index foods and clinical nutrition input. Radical surgical excision was undertaken including left adrenalectomy, nephrectomy, partial pancreatectomy and splenectomy. Post-operative pathology revealed an adrenocortical carcinoma (ACC) measuring 16.4cm in maximum dimension; Ki67 12%; Weiss score 5; lymph nodes negative. Tissue has been stained for IGF-2-IR. Post-operative IGF-2 : IGF-1 ratio normalised to 3.4. The patient is under active follow up with 3-monthly surveillance CT-TAP and has declined Mitotane therapy at present. Conclusion: This is a rare case of ACC secreting multiple hormones, resulting in post-menopausal bleeding and IGF-2 mediated hypoglycaemia. Presentation: Thursday, June 15, 2023