Coexistence of primary aldosteronism and micro-pheochromocytoma: a case report with pathological analysis and literature review.

BACKGROUND: Primary aldosteronism (PA) and pheochromocytoma (PHEO) are both causes of secondary hypertension. Since these two diseases have different pathogeneses, the coexistence of PA and PHEO is very rare and poses challenges in diagnosis and treatment. CASE PRESENTATION: A 65-year-old woman developed paroxysmal hypertension two years ago, accompanied by palpitation, dizziness, headache, and vomiting, and she had a poor response to conventional antihypertensive drugs. Contrast-enhanced computed tomography showed a nodule in the medial limb of the right adrenal gland. A mildly elevated aldosterone to renin ratio and an unsuppressed captopril challenge test met the diagnostic criteria for primary aldosteronism. Normetanephrine was elevated in plasma catecholamine testing. Adrenal venous sampling (AVS) demonstrated bilateral aldosterone excess. Right adrenalectomy was performed after multidisciplinary discussion and resulted in rapid clinical improvement. Postoperative pathology revealed coexistence of a cortical aldosterone-producing nodule (APN), a micro-pheochromocytoma and multiple aldosterone-producing micronodules (multiple APM) in adrenal cortex. A KCNJ5 mutation was found in the APN, representing the first report of this gene mutation in APN in cases coexisting PA and PHEO. CONCLUSIONS: We report a rare case of concurrent PA and micro-pheochromocytoma. This case highlights the importance of early identification and diagnosis, and it provides experience regarding the diagnostic and treatment protocol for such a rare condition. Pathological findings and the KCNJ5 mutation in APN provide directions for subsequent research on the pathogenesis of concomitant PA and PHEO.