Malignancy in pheochromocytoma is indicated by-: (A) Vascular invasion, (B) Mitotic figures, (C) Capsular invasion, (D) metastasis
Answer is D. "Because malignant and benign pheochromocytomas may have an identical histological appearance, the only absolute criterion of malignancy is metastasis"
​"The diagnosis of malignant pheochromocytoma is made only when metastasis is demonstrated"