Plexiform granular cell odontogenic tumor.

Two odontogenic tumors characterized by a previously undescribed histologic appearance are reported. Both lesions consisted of interlacing strands of odontogenic epithelium, with each strand being two cell layers thick. The cells were large and polyhedral in shape, with a granular eosinophilic cytoplasm. The nuclei were arranged "back to back" away from the basement membrane. One of the lesions seems to have originated, at least in part, from the basal layer of the oral epithelium. There is some evidence to suggest that these lesions may represent previously undescribed histologic variants of the ameloblastoma. However, the possibility that they represent a new entity cannot be excluded. For the time being the term plexiform granular cell odontogenic tumor is suggested.