Endocrine Abstracts

Case history: We report a 56-year-old man who was referred to the Endocrinology Clinic with hypokalaemic hypertension. He had a history of bladder cancer 9-years previously, treated with surgery, chemotherapy and BCG therapy. At referral, he was taking Amlodipine 10 mg and Doxazosin 8 mg twice daily with average home blood pressure readings of 160/90 mmHg.

Investigations: Aldosterone to renin ratio (ARR), taken on Doxazosin with potassium 3.6 mmol/l was 3900 (renin 0.2 nmol/l per h and aldosterone 780 pmol/l). Overnight dexamethasone suppression test was normal, excluding co-secretion of cortisol. CT adrenal demonstrated a 9 mm left adrenal adenoma. He underwent adrenal vein sampling, which lateralised to the left adrenal with appropriate suppression on the right, which was concordant with imaging of a left adrenal adenoma. The Adrenal MDT agreed that he should be referred for a left adrenalectomy and he was listed for a left retroperitoneoscopic adrenalectomy.

Results and treatment: At surgery, he had significant perinephritis related to previous BCG therapy and decision to perform a partial adrenalectomy was made. In the postoperative period, he remained hypokalaemic and hypertensive. At day 14 in the Endocrine Clinic, blood pressure was 150/90 mmHg on Amlodipine 10 mg, potassium 3.9 mmol/l on Sando-K 2 tablets bd and ARR 1460. His histology showed normal background adrenal architecture and a benign cortical adenoma. However, postoperative imaging demonstrated a partial left adrenalectomy and a 6 mm nodule in the lateral limb of the left adrenal still visible. The treatment options at this point for persistent primary aldosteronism (PA) were re-do surgery, long-term medical therapy or radiofrequency ablation (RFA). He underwent RFA.

Conclusions and discussion: Post-RFA, he was able to discontinue potassium supplements and antihypertensive therapy. His potassium was 4 mmol/l, renin 0.8 nmol/l per h, aldosterone 70 pmol/l and ARR 88; suggesting cure from PA. The evidence base shows that CT guided-percutaneous RFA is an effective and safe treatment option for PA. However, at present there is insufficient evidence for valid comparison with surgery for resolution of PA and hypertension. As our case demonstrates, it is a justifiable alternative for patients who are unfit or reluctant for surgery.