[Cylindrospiradenomas in Brooke-Spiegler syndrome]

Brooke-Spiegler syndrome is a rare autosomal-dominant inherited disease, characterized by the development of multiple cylindromas and trichoepitheliomas. We report a case in which tumors were found on the head showing histological features of both cylindromas and spiradenomas. These changes were in continuity within the same lesions. Since cylindromas are thought to be apocrine in nature, whereas spiradenomas are eccrine, a contiguous growth within the same neoplasm indicates a conflict concerning their histogenesis. The available histological, ultrastructural and immunohistochemical studies have not produced any criteria to allow an unequivocal classification, suggesting instead that both tumors arise from similarly differentiated cells, perhaps from pluripotent epithelial cells. In our opinion, it seems impractical to strictly classify cylindromas and spiradenomas into tumors of apocrine or eccrine differentiation. Moreover, at least for those cases of Brooke-Spiegler syndrome, where both tumors are found in immediate vicinity to each other, we propose the term cylindrospiradenoma.