Squamous odontogenic tumor of the maxilla: report of a case.

A case of squamous odontogenic tumor (SOT) of the maxilla related to an embedded tooth in a 42-year-old Japanese woman is described. The patient felt a slight pain of her left maxilla 2 months before visiting our dental hospital. Histologically, the tumor consisted of a proliferation of round and elongated epithelial islands of well-differentiated squamous epithelium separated by a fibrous stroma. The epithelial nests varied in size, and were composed of cuboidal or squamous cells of basal layer and matured intermediate cells with prominent intercellular bridges. Although no calcified materials were found, microcystic degeneration was occasionally observed in the epithelial islands. These findings indicated that this tumor is a SOT of the maxilla.