Peripheral squamous odontogenic tumor.

A case of peripheral squamous odontogenic tumor is described in a 60-year-old female who presented with a sessile growth in the right posterior mandible. Radiographic examination revealed no evidence of a central lesion in bone. With the characteristic histopathological picture of benign-appearing islands of squamous epithelium scattered randomly against a background of mature fibrous connective tissue, the tumor was diagnosed as peripheral squamous odontogenic tumor (PSOT). The epithelial islands showed peripheral cuboidal or flattened cells, microcyst formation, individual cell keratinization, and keratin pearl formation.