Endocrine Abstracts

A 65-year-old man presenting with urinary symptoms was incidentally discovered to have an adrenal mass on imaging. Abdominal computed tomography (CT) revealed a 9.5 x 8 cm heterogenous solid right adrenal tumour with no evidence of metastatic disease. Family history included a brother who died from metastatic carcinoid and another brother who died from metastatic neuroendocrine tumour. The initial differential lay between adrenocortical carcinoma (ACC) or a pheochromocytoma. The plasma fractionated normetanephrine was elevated at 14439 pmol/l(0-1180), metanephrine 15202 pmol/l(0-510), 3-MT 415 pmol/l(0-180) led to a presumed preoperative diagnosis of pheochromocytoma. However, there was also evidence of autonomous cortisol secretion with a positive overnight dexamethasone suppression test of 209 nmol/l, a suppressed ACTH and an elevated DHEAS of 14.9 umol/l. An I-123 metaiodobenzylguanidine (MIBG) scan demonstrated heterogenous avidity in the adrenal lesion. Due to his previous surgeries, right adrenalectomy via an open right subcostal approach was opted with a possible capsule breach. Histology of the resected tumour was consistent with an 8 cm, 222g phaeochromocytoma with a PASS of 11/20 with areas of atypical mitoses, tumour stain positive for synaptophysin and chromogranin-A, S100, melan-A and inhibin, however calretinin was negative. Ten weeks post operatively CT scan demonstrated significant disease recurrence in the tumour bed with a 9.4 x 5.2 cm in size mass with encasement of the IVC and other vessels and perinephric tumour deposits and a mass invading a segment of the liver. Plasma metanephrines were normal and the lesions were not MIBG-avid. A significant elevation in DHEAS to >27umol/l with normal plasma metanephrine was highly suggestive of adrenocortical carcinoma. A CT guided biopsy was consistent with adrenocortical carcinoma. Histology demonstrated pleomorphic cells with mitotic rate 12/10 hpf. Immunohistochemistry was positive for adrenocortical markers for Melan A, inhibin and synaptophysin with a Ki67 proliferation 80-90%. On comparison with the previous resected specimen, the appearance was morphologically similar, although elements of medullary neoplasia were also present making this an extremely challenging histological diagnosis. He had negative genetic testing for the MEN1 gene, including DP53, AIP MEN1, CDKN1B, RET and CDC73. He was diagnosed as metastatic adrenocortical carcinoma with malignant Cushing’s syndrome and commenced on mitotane and received six cycles of Cisplatin/Etoposide/Doxorubucin. His symptoms of Cushing’s improved and serial imaging following the completion of chemotherapy shows an excellent response to treatment, with reduction of the tumour burden in the liver and adrenal bed.