title: Ultrastructure of a sialadenoma papilliferum.
abstract: A case of sialadenoma papilliferum occurring in the hard palate of a 56-year-old Japanese man is presented. A pedunculated, nonencapsulated and small mass consisted of predominantly exophytic proliferation of a double- or multi-layered duct epithelium with a concomitant overgrowth of squamous epithelium. This characteristic papillary lesion was demonstrated by electron microscopic examination to be mainly composed of salivary gland duct epithelium intermingled with a few of myoepithelial cells. Moreover, these duct cells were interpreted ultrastructurally as an intercalated duct cell. This finding indicates that sialadenoma papilliferum may be an intercalated duct cell in origin.
mesh_terms: D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D008875:Middle Aged; D010157:Palatal Neoplasms / Q000648:ultrastructure*; D012468:Salivary Gland Neoplasms / Q000648:ultrastructure*