Abstract: | The removed pheochromocytomas of 25 patients aged from 25 to 72 years have been studied. Among them 5 tumors have had bilateral character, 8 pheochromocytomas have been diagnosed as malignant, 4 patients have had metastases. The average size of benign pheochromocytomas has been 4.0 cm, malignant - 4.5 cm. The majority of malignant tumors have had areas with diffusing growth patterns. The results of immunohistochemical study of benign and malignant pheochromocytomas have had small differences. The study of tumor ultrastructure hasn't found out their biological potential. |