Differences between sporadic pheochromocytoma and pheochromocytoma in multiple endocrine neoplasia, type 2

We studied the gross and microscopic pathology of the adrenal gland in 69 cases of sporadic phenochromocytoma in order to develop a profile of the neoplasm to compare with that of pheochromocytoma observed in the syndrome of multiple endocrine neoplasia, type 2 (MEN 2). The results showed that sporadic pheochromocytoma was a unicentric (93%), unilateral (100%) neoplasm, which was associated with normal extratumoral adrenal medulla (100%). The findings contrast with those encountered in the adrenal gland in MEN 2, in which the tumor involvement is frequently multicentric, usually bilateral, and associated with extratumoral medullary hyperplasia in cases of early involvement. Therefore, the interpretation of the results of pathologic examination of a pheochromocytoma should be immediately communicated to the surgeon.