Endocrine Abstracts

A 34-year-old female presented with an 18 months history of secondary amenorrhoea, hirsutism, weight gain and low mood. Examination confirmed typical stigmata of Cushing’s syndrome with skin thinning, purpura, acne, facial plethora, central adiposity and hypertension. Investigations revealed fT₄ 14.7 pmol/l, fT₄ 4.1 pmol/l, TSH 0.71 μ/l, prolactin 377 μIU/ml, FSH 3.5 μ/l, LH 2.2 μ/l, oestradiol 140 pmol/l, testosterone 5.1 nmol/l, androstenedione 23.2 nmol/l, DHEAS 8.8 μmol/l, SHBG 24 nmol/l and urinary free cortisol 1244 nmol/24 h. Pre low dose dexamethasone cortisol 672 nmol/l and ACTH<5.0 ng/l. Post low dose dexamethasone cortisol 600 nmol/l and post high dose dexamethasone cortisol 606 nmol/l. CT scan demonstrated a 4.5 cm diameter right adrenal mass and no other abnormalities. Laparoscopic right adrenalectomy was performed at a tertiary centre and benign histology reported. At review 2 months post operatively Cushingoid features had improved and mean cortisol level on a day profile was 382 nmol/l. Four months post operatively Cushingoid features had worsened to presentation severity with a 0900 h cortisol 1054 nmol/l and ACTH<5.0 ng/l. CT scan demonstrated a 12.5 cm diameter mass invading the right lobe of the liver and pulmonary metastases. Biopsy of the liver lesion and review of original histology both confirmed adrenocortical carcinoma. Despite treatment with chemoembolisation, metyrapone, fluconazole and mitotane she died 12 months post initial presentation. The last month of life was complicated by spontaneous hypoglycaemia which responded well to i.v. octreotide. Investigations confirmed the aetiology of the hypoglycaemia with IGF2 grossly elevated at 96.2 nmol/l and IGF2/IGF1 ratio >30.

This case demonstrates the diagnostic pitfalls in histological diagnosis of adrenal carcinoma and the very rare complication of hypoglycaemia due to tumour secretion of IGF2.