Further studies of a transplantable rat pheochromocytoma

Additional histopathological and immunocytological studies were completed on the serially transplanted Warren rat pheochromocytoma. Special efforts were made to characterize features of the primary tumor common to pheochromocytomas, as well as features of the primary tumor commonly found in neuroblastoma. In summary this study found evidence for a composite primary tumor exhibiting a dual differentiative expression of both pheochromocytoma and neuroblastoma. We feel this reflects a possibility that this primary tumor arose from a common progenitor cell in the neural crest.