Sclerosing odontogenic carcinoma in the mandible

We report a case of an asymptomatic sclerosing odontogenic carcinoma in a 68-year-old woman. A bulge was noted in the anterior mandibular region, and it increased rapidly without clinical symptoms. On computed tomography, a radiolucent osteolytic lesion was identified in the central incisor apex of the mandible, and the labial cortical bone disappeared. Magnetic resonance imaging showed an internal heterogeneous circular mass outside the alveolar region. Pathological assessment of a biopsy specimen did not lead to a definitive diagnosis, but a benign odontogenic tumor was suspected. The tumor was resected en bloc with 4 incisors. The stem of the tumor was attached to the alveolar bone, but it was mainly outside the bone. Histopathological examination of the surgical specimen showed a capsule under the epithelium and no cellular atypia with bland cytoplasmic cuboidal or polygonal epithelial cells forming a small circle or polygon in the sclerosing stroma. A similar tumor was scattered in the alveolar bone. Immunohistologically, the tumor was positive for cytokeratin (AE1/AE3) and p63, and only a small number of Ki-67-positive cells were noted (approximately 1%). The tumor in our case was not consistent with odontogenic tumors in previous classifications. Based on previous findings, clinical behavior and immunohistological findings, the final diagnosis was a sclerosing odontogenic carcinoma. There has been no recurrence or metastasis 5 years after surgery.