Malignant giant pheochromocytoma: a case report and review of the literature.

Malignant pheochromocytoma is a rare disease and surgical resection is the only curative treatment. There are no definitive histological or cytological criteria of malignancy, as it is impossible to determine this condition in the absence of advanced locoregional disease or metastases. We report a case of a patient with a giant retroperitoneal tumour, the second largest to be published, which was diagnosed as a malignant pheochromocytoma; it was treated with surgery. The literature is reviewed to evaluate tumour features and criteria to distinguish between benign and malignant pheochromocytomas.