Unusual chromaffin cell differentiation of a neuroblastoma after chemotherapy and radiotherapy: report of an autopsy case with immunohistochemical evaluations.

Abstract

Neuroblastomas are derived from neural crest cells that are capable of multilineage differentiation. Ganglionic neuronal differentiation of childhood neuroblastoma is seen with increasing age, leading to more differentiated tumors called ganglioneuroblastomas or ganglioneuromas. Despite the fact that neuroblastomas most often arise from the adrenal medulla, chromaffin-cell differentiation in neuroblastomas is not widely recognized. Tumor cells with a chromaffin-cell nature have only been detected using histochemical techniques in neuroblastoma cell lines or focal areas of certain in vivo tumors. We describe a neuroblastoma that exhibited an unusual differentiation toward chromaffin cells in a patient that had been treated with surgery, intensive chemotherapy, and radiotherapy. Although a biopsy specimen of the retroperitoneal primary tumor was extensively necrotic, possibly because of a previous chemotherapy regimen, surgically resected metastatic tumors of bilateral ovaries were viable and diagnosed as poorly differentiated neuroblastomas according to the International Neuroblastoma Pathology Classification system. However, metastatic tumors of bilateral lungs examined at the time of autopsy exhibited histologic features similar to those of a pheochromocytoma/paraganglioma, and immunohistochemical examinations demonstrated that these tumors were composed of extra-adrenal chromaffin cells. This case confirms that neuroblastomas in childhood can transform into pheochromocytoma/paraganglioma-like tumors under special conditions.