Clear Cell Odontogenic Carcinoma: a Clinicopathological and Immunocytochemical Analysis.

Clear cell odontogenic carcinoma (CCOC) is a rare odontogenic tumor associated with aggressive clinical behavior, metastasis and low survival. To date, only 67 cases have been described in the English language literature, and an understanding of the behavior of CCOC has been based on limited case reports. The aim of the research was to further reveal the features of CCOC. We report 5 new cases of CCOC, with a mean age of 52.4 years. The clinical and histopathologic data of the disease obtained from earlier literature (95 cases) and the 5 new cases were analyzed. Data were extracted, including demographics, histopathologic findings, clinical presentation, primary treatment and outcomes. Immunohistochemical results revealed that the cancer is positive for AE1/AE3, EMA and CK19, negative for smooth muscle actin SMA, Vim and S-100. EWSR1 translocation was also observed in the new cases, which may help in the diagnosis of CCOC. Metastases of CCOC were rare, but the local recurrence rate of CCOC rose to 42%. The best treatment for patients with CCOC is wide local excision combined with regional lymph node dissection.