[A case of Endocrine Active Retroperitoneal Ganglioneuroma, Difficult to Differentiate From Adrenal Pheochromocytoma]

A 66-year-old woman who had been receiving medication for hypertension and hyperlipidemia was referred to our hospital for evaluation of a left adrenal tumor (12×8 mm) that was incidentally detected on computed tomography. Her 24-hour urinary catecholamine level was elevated, and metaiodobenzylguanidine (MIBG) scintigraphy revealed increased uptake in the area around the left adrenal gland, necessitating laparoscopic adrenalectomy for preoperative diagnosis of left adrenal pheochromocytoma. Intraoperatively, we detected a para-aortic tumor behind the adrenal gland, and this lesion was excised together with the adrenal gland. However, manipulation of the para-aortic tumor led to elevation in the blood pressure to 170 mmHg. Histopathological examination of the resected specimens revealed an adrenocortical adenoma and a para-aortic ganglioneuroma, consisting of ganglion cells, nerve fibers, and Schwann cells. The patient's blood pressure normalized immediately postoperatively, and MIBG scintigraphy revealed a negative result. Endocrine active ganglioneuromas are rare, and to our knowledge, currently only 8 cases (including ours) have been reported in the Japanese and English literature.