Central Odontogenic Fibroma combined with Central Giant Cell lesion of the mandible. Immunohistochemical profile.

Central Odontogenic Fibroma is a benign neoplasm of mesenchymal origin that makes up less than 5% of odontogenic tumors. There is a variation of this lesion that includes a zone of giant cells. This neoplasm is characterized by fibroblast proliferation, a component of apparently inactive odontogenic epithelium within a mature connective tissue stroma and multinucleated osteoclast-like giant cells. Clinically, it manifests as a slow-growing central lesion, which causes painless cortical expansion and may occasionally cause the displacement of adjacent dental organs or resorption. We present a new case of this combined lesion that was revealed radiographically as a well-defined radiolucent area in the left mandibular body. Histologically, we identified a mesenchymal lesion composed of mature fibrocellular tissue, where islands and cords of odontogenic epithelium and fibrocellular areas with numerous giant cells can be distinguished. The immunohistochemical examination was positive for giant cells with the marker CD68 and positive for epithelium cords with the marker CK19, which indicates that this an odontogenic lesion