Abstract

PURPOSE
There are no specific clinical and histopathologic characteristics of malignant pheochromocytoma and the optimal treatment modality has not been established yet. We analyzed the clinical and histopathologic features of malignant pheochromocytoma and treatment results.
MATERIALS AND METHODS
We reviewed the clinical records of 10 patients with malignant pheochromocytoma diagnosed at Seoul National University Hospital from March 1987 to June 1998.
RESULTS
Nine of 10 (90%) patients had functional tumors. The biochemical laboratory findings showed elevated 24-hour urine VMA level in nine patients available. The median size of the tumors was 11x11 cm. Six of 10 (60%) patients were initially diagnosed as malignant tumors because of direct invasions to adjacent tissues or distant metastases. On the other hand, remaining 4 patients were initially diagnosed as benign, but the distant metastases developed metachronously after resection of the primary lesion. The median duration between the initial operation and the detection of metastases was 57 months (range: 47~72 months) in these patients. The liver was the most common site of metastases (60%). With regards to the histopathological features, most of the tumors (87.5%) showed capsulation, necrosis and hemorrhage. The findings of lymphatic invasion, angio-invasion, and mitosis were found in 62.5% of the cases. All but 2 patients were initially treated with radical operation for the primary lesions. The disease recurrences or metastases occurred in 7 out of 10 patients. Of these, 4 patients were treated with chemotherapy or interferon- a after recurrences. Overall, the median survival for all patients was 82 months (range: 37~143 months). Two patients is alive and only one patient is alive without recurrence.
CONCLUSION
The careful follow-up for at least 5 years and the aggressive multi-disciplinary therapy may be needed for the diagnosis and the management of malignant pheochromocytoma.

• Keywords: Malignant pheochromocytoma