Case of myoepithelioma originating from the palate: collagenogenesis in myoepithelial tumor cells.

We report a case of myoepithelioma of the palate in a 53-yr-old man. Myoepithelioma cells consisting of both plasmacytoid type and spindle type were obtained. A reticular pattern composed of a mosaic arrangement of hyaline-like abundant cytoplasm, and scant matrix and considerable fiber formation were characteristic features of the plasmacytoid type; granular cytoplasm and a snake-like shape were characteristic features of the spindle type. These are important points in differentiating this tumor from cellular type pleomorphic adenoma. The present study shows that tumorous myoepithelial cells can synthesize and secrete extracellular components such as proteoglycans, basal lamina, collagen fibers, and elastic fibers.