[Malignant adrenal pheochromocytoma--problems in evaluating clinical diagnosis and morphologic extent]

Reports on three patients with malignant adrenal phaeochromocytoma are used as a basis for discussion of involved in diagnosing functionally inactive paragangliomas and in discriminating between benign and malignant adrenomedullary tumours. Malignancy can so far only be ascertained in such neoplasms by evidence of metastatic growth. Our findings, however, show that increased tumour weight (more than 200 g), high mitotic activity (more than 5 mitoses per HPF) and loss of S-100 protein-positive subtentacular cells make it possible to distinguish high-risk cases (with increased risk of recurrence and metastasis).