IADR Abstract Archives

Cemento-ossifying fibroma with odontogenic epithelium: an unusual microscopic finding

Cemento-ossifying fibroma is a variant of ossifying fibroma that develops on the alveolar ridge of the jaws. For decades this tumor was typed as a benign fibro-osseous lesion. The 2017 World Health Organization classification of head and neck tumors types it as a benign mesenchymatic odontogenic tumor, evidencing the controversy regarding the origin of this entity. Histologically, it is characterized by a hypercellular fibroblastic proliferation containing varying amounts of mineralized, osseous, and cementum-like structures. There are few reports on cement-ossifying fibroma, and most describe isolated cases presenting with ossifying fibromas and benign fibro-osseous lesions. Its clinical-radiographic and microscopic appearance as well as therapeutic approach are under debate. OBJECTIVE: To present a histological finding observed in cemento-ossifying fibromas. METHODS: A retrospective study of all benign fibro-osseous lesions filed in the archives of the Surgical Pathology Laboratory of the Oral Pathology Department – School of Dentistry, UBA – during a 55-year period, was carried out. Ninety cases of cemento-ossifying fibromas were retrieved; microscopic features were evaluated and immunohistochemical techniques were performed. RESULTS: Three cases of cemento-ossifying fibroma showed islands and cords of odontogenic epithelium embedded in the mesenchymal proliferation. Immunohistochemical staining using AE1-AE3 and CK5 antibodies was positive. All 3 cases presented in the posterior region of the mandible, in the sixth decade of life; two occurred in women and one in a man. Radiographic images showed mixed osteolytic lesions.  CONCLUSIONS: The microscopic finding of odontogenic epithelium in a cemento-ossifying fibroma has not been described to date. The odontogenic epithelium would lend support to the possible origin of the lesion, which would arise from tissue remnants of odontogenesis. The presence of epithelium in the neoplastic mesenchyme would facilitate histopathological diagnosis of this entity.
Argentine Division Meeting
2018 Argentine Division Meeting (Córdoba, Argentina)
Córdoba
2018

Accepted Abstracts
  • Villegas Padilla, Krissya Maria  ( Universidad de Buenos Aires )
  • Itoiz, Maria  ( Universidad de Buenos Aires )
  • Cabrini†, Romulo Luis  ( Universidad de Buenos Aires )
  • Paparella, Maria Luisa  ( Universidad de Buenos Aires )
  • Programación Científica UBACyT 2018-2019/ 20020170200308BA
    Oral and Poster Presentations