Pheochromocytoma complicated by cyanotic congenital heart disease: a case report.

Coincidental cyanotic congenital heart disease and pheochromocytoma is uncommon, although some cases have been reported. We describe a girl aged 15 yr and 11 mo with pheochromocytoma and tricuspid atresia treated by performing the Fontan surgery. The patient did not have any specific symptoms of syndrome related to pheochromoytoma or a family history of pheochromocytoma. During cardiac catheterization, her blood pressure increased markedly, and an α-blocker was administered. Catecholamine hypersecretion was observed in the blood and urine, and abdominal computed tomography revealed a tumor in the right adrenal gland. Scintigraphy showed marked accumulation of (123)I-metaiodobenzylguanidine in the tumor, which led to a diagnosis of pheochromocytoma. We did not detect any germline mutations in the RET, VHL, SDHB, SDHD, TMEM127, or MAX genes. This patient had experienced mild systemic hypoxia since birth, which may have contributed to the development of pheochromocytoma.