Abstract
We report a case of sebaceous adenoma arising from normal skin without organoid nevus. The patient was a sixty-two-year-old man who had a solid papule on the forehead. Histological examination of this lesion showed a intracutaneous nodule with well-defined lobules consisting of peripheral germinative and central sebaceous cells. More than half of these lobules were composed of mature sebaceous cells. In the ultrastructual study, the cytoplasm of the tumor contained numerous lipid droplets. Immunohistochemical study revealed epithelial membrane antigen to be detected only in mature sebaceous cells of this tumor. We concluded that epithelial membrane antigen was a differentiation antigen to mature sebaceous cells and useful in establishing a differential diagnosis between sebaceous adenoma and sebaceous epithelioma.
