Pheochromocytoma with no Evidence of Catecholamine Hypersecretion in Preoperative Biochemical Tests—A Case Report—

Abstract

A 34-year-old man with multiple endocrine neoplasia (MEN) 2A presented with recurrence of thyroid medullary carcinoma. A preoperative CT scan revealed a left adrenal mass. ¹²³I-meta-iodobenzylguanidine (MIBG) scintigraphy showed increased accumulation in the left adrenal mass, but no excessive secretion of catecholamines was noted These preoperative findings did not meet the diagnostic criteria for pheochromocytoma. Because the adrenal mass affected the MEN2A patient, it was reasonable to suspect the left adrenal mass as a pheochromocytoma, and an alpha-blocker was administered preoperatively according to the perioperative management of pheochromocytoma. During the operation, the patient's blood pressure elevated due to the surgical maneuver, but antihypertensive treatment by the alpha-blocker was effective, and the operation could be completed safely. Even in pheochromocytoma, endocrine function tests may not demonstrate excessive catecholamine secretion, and perioperative management based on comprehensive clinical findings is important to ensure safe treatment.