Adrenocortical Carcinoma With 2 Distinct Syndromes From Secretion of Insulin-Like Growth Factor 2 and Steroid Hormones

Non-islet cell tumor hypoglycemia as a result of insulin-like growth factor (IGF)-2 secretion is rare. A 59-year-old woman was referred with postmenopausal bleeding due to endometrial hyperplasia. Serum testosterone, estradiol, and adrenal androgens were elevated with suppressed gonadotropin concentrations. Cross-sectional imaging demonstrated a large left adrenal mass. The patient subsequently presented acutely with hypoglycemia. During a supervised fast, symptomatic hypoglycemia occurred within 5 hours. Serum samples drawn prior to hypoglycemia correction revealed an elevated IGF-2:IGF-1 ratio of 60.7 (normal <10) with low paired C-peptide and insulin, consistent with an IGF-2-secreting tumor. Hypoglycemia was managed with low-glycemic index foods and radical surgical excision was undertaken. Postoperative pathology revealed an adrenocortical carcinoma (ACC); Ki67 12%; IGF-2 positive immunostaining. This case demonstrates a rare IGF-2-secreting ACC causing clinically significant hypoglycemia with positive immunostaining for IGF-2 in addition to biochemical hyperandrogenism resulting in endometrial hyperplasia and postmenopausal bleeding. This case encompasses 2 unique syndromes from the cosecretion of both peptide factor and steroid hormone.