Complete Unilateral Adrenalectomy is Recommended to Prevent Residual Disease in Unilateral Primary Aldosteronism

A 55-year-old man with hypertension and hypokalemia was diagnosed with primary aldosteronism (PA). Adrenal vein sampling confirmed right-sided lateralization, and computed tomography (CT) revealed a right adrenal tumor. Complete unilateral adrenalectomy was initially planned, but due to surgical challenges associated with a retroperitoneal approach and visceral obesity, he underwent laparoscopic partial adrenalectomy, removing an adrenal tumor. However, histopathological examination showed that the lesion was CYP11B2-negative, and hypertension and elevated aldosterone levels persisted, indicating residual aldosterone-producing tissue. A follow-up CT scan confirmed complete resection of the previously identified tumor, raising concerns about microscopic or multifocal aldosterone-producing nodules. Subsequently, complete unilateral adrenalectomy of the remaining right adrenal gland was performed, resulting in normalization of aldosterone levels and well-controlled blood pressure with nifedipine (80 mg/day). Pathological examination revealed a well-demarcated nodular lesion continuous with adrenal tissue. Immunohistochemical staining for CYP11B2 was positive, confirming a right aldosterone-producing nodule. PA often involves multinodular or microscopic aldosterone-producing lesions, which partial adrenalectomy may not completely remove. This case highlights the limitations of partial adrenalectomy in unilateral PA and supports complete unilateral adrenalectomy as the preferred surgical approach to achieve complete disease resolution.