Endocrine Abstracts

Adrenal cortical carcinoma (ACC) is notorious for its aggressiveness and poor prognosis. A 71-year-old woman was found to be hypokalaemic with a serum potassium of 2.6 mmol/l [reference 3.6-5.0 mmol/l] on routine blood screening. Previous serum potassium readings were normal. She was asymptomatic and reported no gastro-intestinal losses. Her medical history was significant for hypertension, hyperlipidemia and hypothyroidism following total thyroidectomy for Graves’ Disease. She had been on stable doses of amlodipine, simvastatin and levothyroxine. There was no use of traditional medications or diuretics. Two weeks later, despite being on potassium replacements, she re-presented with persistent hypokalaemia 2.5-3.2 mmol/l associated with increased bicarbonate 36.7 mmolL [reference 19.0-29.0 mmol/l] and proximal myopathy. She was normotensive and her weight was stable. Besides facial acne and proximal myopathy, no discriminatory features of Cushing’s syndrome were present. 24-hour urinary potassium of 88 nmol indicated urinary potassium loss. Further investigations revealed a markedly elevated 0800 hours cortisol at 1080 nmol/l, with an undetectable adrenocorticotropic hormone (ACTH). Further investigations revealed hyperandrogenism with total testosterone 6.9 nmol/l [reference 0.30-2.8 nmol/l], 17alpha hydroxyprogesterone 11.1 nmol/l and dehydroepiandrosterone-sulfate (DHEA-S) 25.3 umol/l [1.1-11.8 umol/l]. This raised concerns for ACC with non-ACTH dependent hypercortisolism. Cross sectional imaging showed a 7.4 × 6.5 cm² enhancing mass in the left adrenal with tumour thrombus extending to the left adrenal vein, with no distant metastases. Within a month of diagnosis, the tumor had enlarged to 10 × 8 × 7.2 cm³ when she underwent open left adrenalectomy. Histology revealed a high-grade tumour invading through the adrenal capsule into periadrenal adipose tissue. Post-operative day three 0800 hours cortisol of 383 nmol/l was worrying for incomplete resection. Nevertheless, ACTH and adrenal androgens normalized shortly postoperatively. She was started on adjuvant mitotane but shortly developed rapidly worsening transaminitis with alkaline phosphatase 105 U/l [reference 12-42 U/l] and gamma-glutamyl transferase 1138 umol/l [reference 7-32 umol/l] which contraindicated further use of mitotane. Repeat imaging revealed extensive loco-regional and distant metastases in her liver and lungs. 0800 hours cortisol had risen to 1261 nmol/l (while on mitotane) as did adrenal androgens. Her prognosis was guarded and metyrapone was initiated for symptom control of hypercortisolism particularly that of muscle weakness, with some initial relief. She passed away three weeks later, within three months from diagnosis. This case highlights the aggressive nature of ACC and the importance of having a high index of suspicion to allow early diagnosis and intervention, and the need for research and new therapeutics.