An Unusual Case of a Composite Pheochromocytoma With Neuroblastoma

Abstract

Composite pheochromocytoma (CP) is a rare tumor of the adrenal medulla, consisting of neuroendocrine and neural components. Despite similar neural crest origins, pheochromocytomas and neurogenic tumors are distinct entities. Symptoms may arise from hypersecretion of hormones by either component; however, not all patients present with classic symptoms. Moreover, various medical conditions and substances can confound screening tests and complicate the diagnosis. The patient, a 46-year-old male, was seen in the endocrine clinic regarding a 2-year history of paroxysmal headaches, palpitations and diaphoresis. His medical history was significant for hypothyroidism and substance misuse (nicotine, marijuana and cocaine). Family history was negative for pheochromocytoma, hyperparathyroidism or thyroid malignancies. He was found to be hypertensive in clinic, and two cafe-au-lait spots and bilateral axillary freckles were noted on dermatological examination. Pheochromocytoma was suspected and investigations revealed 24-h urinary catecholamines, metanephrines and vanillylmandelic acid levels that were substantially elevated. He was asked to repeat the urine collection while abstaining from cocaine, given the potential confounding with cocaine-induced elevations of catecholamines and their metabolites; however, the patient did not comply with this. His plasma free metanephrines and chromogranin A were later found to be elevated. Abdominal computed tomography revealed a 5.8 × 5 cm mass in the left adrenal gland, with an attenuation of 40 Hounsfield units. He underwent an uncomplicated laparoscopic left adrenalectomy, after which his blood pressure normalized. Histological features of the tumor revealed findings consistent with a typical pheochromocytoma with neuroblastomatous infiltrates comprising < 5% of the tumor. The mitosis karyorrhexis index was low and there was no ganglioneuromatous infiltrate evident. Medical oncology was consulted in view of the histopathological findings, and no adjuvant therapy was recommended. Unfortunately, he did not fully comply with repeat imaging or biochemical evaluation. Six months postoperatively, the patient remains completely asymptomatic and normotensive. Cocaine-induced catecholamine effects can clinically mimic pheochromocytoma, thereby complicating the diagnosis. In addition, the biologic behavior of CP with neuroblastoma is uncertain and warrants oncologic assessment and surveillance.




J Endocrinol Metab. 2014;4(1-2):39-46
doi: http://dx.doi.org/10.14740/jem211w