CASE REPORT

RECURRENT UNILATERAL ALDOSTERONE-PRODUCING ADRENAL ADENOMA

Abstract

INTRODUCTION/BACKGROUND
Primary aldosteronism (PA) is the most common cause of secondary hypertension. While adrenalectomy can be curative in unilateral cases, recurrence after total adrenalectomy is exceedingly rare. We describe a rare case of recurrent PA requiring two adrenalectomies, eight years apart.

CASE
A 43-year-old male was diagnosed with hypertension at age 30 and initially required four antihypertensive agents for blood pressure control. In 2012, biochemical screening confirmed PA, with an aldosterone-renin ratio (ARR) of 1991 and a post-saline suppression aldosterone level of 600 pmol/L. Adrenal CT revealed a hypodense lesion in the lateral limb of the left adrenal gland measuring 0.9 × 1.3 cm with HU of –4 to 20. Adrenal venous sampling (AVS) was performed but yielded inconclusive results due to failed cannulation of the left adrenal vein. In 2015, he underwent retroperitoneoscopic left adrenalectomy, with histopathology confirming an adrenal cortical adenoma. Postoperatively, his blood pressure improved and was maintained on a single antihypertensive agent.

Over the following years, his blood pressure gradually increased, requiring multiple medications. In 2023, repeat screening showed an ARR of 238 and adrenal CT showed a recurrent lesion in the left adrenal bed. A second left adrenalectomy was performed in December 2024. Postoperatively, his blood pressure normalized without the need for antihypertensives.

This case highlights the rare occurrence of recurrent PA after unilateral adrenalectomy. Possible mechanisms include residual hyperfunctioning adrenal tissue or the development of a new aldosterone-producing lesion in the ipsilateral adrenal bed. Some studies suggest that patients with certain genetic mutations such as KCNJ5 may be predisposed to developing multiple aldosterone-producing nodules, either at the time of initial surgery or later in the remaining adrenal tissue.

CONCLUSION
Recurrent PA after unilateral adrenalectomy is rare but clinically significant. Lifelong monitoring of blood pressure post adrenalectomy is essential. Repeat surgical intervention can achieve biochemical remission and restore blood pressure control in cases of recurrence.