An electron microscopic study of sebaceous epithelioma. A case report with two new observations on lipid droplet formation.

A lesion presenting a typical histopathological picture of sebaceous epithelioma comprised three kinds of cells; immature, transitional, and mature cells corresponding to the components of the normal sebaceous gland. Melanocytes and melanosomes were absent. These findings clearly distinguished the tumor from basal cell epithelioma, and it was concluded that sebaceous epithelioma represents a primary neoplasm of the sebaceous gland. New observations on lipid droplet formation are made with regard to the glycogen-containing cytolysome - tentatively designated a Liposome - and membrane structures around the lipid droplet found in mature cells.