Clinical and pathological data of 10 malignant pheochromocytomas: Long-term follow up in a single institute

Background: Malignant pheochromocytomas are rare. Many controversies still exists in clinical practice. We report the clinical and histological data of long-term follow up in 10 patients with malignant pheochromocytoma. Methods: The clinical charts of 10 patients with malignant pheochromocytoma from a single institute were reviewed. The diagnosis of pheochromocytoma was confirmed at surgery. All patients had metastases in sites where chromaffin tissue was normally absent. Results: The median follow-up period was 5.5 years (range, 2-20 years). Extra-adrenal tumors occurred in four patients including paraganglioma tumors in three cases and bladder tumor in one case. Regional lymph node metastases were noted in six patients. Distant metastases were located in the lungs of two patients, in the bones of two patients and in the liver of one patient. Histological characteristics were not helpful for diagnosis of malignancy and for prediction of prognosis. Metastases were present in postoperative pathology in seven patients. In another three patients, metastases were discovered 6 months to 10 years after surgery. Three patients received chemotherapy and one patient received combination therapy of high-dose ¹³¹I-meta-iodobenzylguanidine (¹³¹I-MIBG) therapy and chemotherapy. All patients achieved long-term survival except for two who died of metastasis 1.5 years and 2 years after diagnosis. Conclusions: Early complete resection and adjunctive lymphadenectomy can cure malignancy. Close long-term follow up for more than 10 years after surgery is necessary in patients with pheochromocytoma. The possibility of malignancy should be kept in mind even though the initial pathology is benign.