Oncologic aspects of pheochromocytoma: the importance of follow-up.

During a 33-year period at Vanderbilt University Medical Center and its long-standing affiliated hospitals, Veterans Administration Medical Center and Metropolitan Nashville General Hospital, 69 patients with pheochromocytoma were seen. Despite the fact that hypertension was present in all patients at initial admission, in 11 patients seen during the 1950s the clinical diagnosis of pheochromocytoma was not made and the existence of this tumor was discovered at autopsy examination. In 58 patients the clinical diagnosis of pheochromocytoma was made and surgical excision of pheochromocytoma (or biopsy only in two cases) was carried out. One patient died during the initial postoperative period (1.7%). All of the operative survivors were followed to date or the death, with the exception of three who were lost to follow-up at 18 months and 7 and 11 years, respectively. The incidence of malignant disease in this carefully followed group of patients with pheochromocytoma was impressive. Nine of 69 patients (13%) proved to have malignant pheochromoblastoma, all but one of whom have died. Additional malignant tumors have occurred in two of these nine patients (22%) with proved malignant pheochromoblastoma and in 14 of 60 patients (23%) with benign pheochromocytoma. The overall incidence of additional malignant tumors in the collective group of patients with the histopathologically confirmed diagnosis of pheochromocytoma was thus 23% (16/69 patients). It is also interesting that a variety of benign neoplasms occurred in the 60 patients with benign pheochromocytomas (9/60; 15%). If the nine patients with malignant pheochromoblastoma are added, the overall incidence of malignant disease in these 69 patients with pheochromocytoma is 25/69 or 36%. Follow-up of patients with pheochromocytoma is mandatory on a lifetime basis and preferably by the operating surgeon.