Intraosseous carcinoma of the mandible composed of cells expressing myoepithelial cell‐associated antigens

Abstract

Carcinomas are rarely observed centrally in mandibular and maxillary bone. Etiology of intraosseous squamous cell carcinoma is thought to involve derivation from remnants of the odontogenic epithelium. Mucoepidermoid carcinoma is also rarely observed centrally in the mandibular and maxillary bone. Previous analyses raised the possibility that the tumor arose from entrapped salivary elements or from metaplastic odontogenic epithelia. Herein is described an intramandibular carcinoma with characteristic various morphologies. The tumor was composed of epidermoid cells, clear cells, mucous cells and intermediate cells, which were surrounded by cellular-rich collagenous stroma. The epidermoid cells, clear cells and mucous cells formed solid sheets, and the clear cells and intermediate cells formed trabecular structures. Sparse cell regions were partly accompanied by clear cells and mucous cells. Immunohistochemistry was positive for myoepithelial markers in the trabecular portion of the tumor. These findings suggest that this is a unique case of intramandibular mucoepidermoid carcinoma that includes tumor cells expressing myoepithelial cell-associated antigens.