CLEAR CELL ODONTOGENIC CARCINOMA: REPORT OF 3 NEW CASES AND SUMMARY OF 124 REPORTED CASES

Abstract

<h3>Background</h3> Clear cell odontogenic carcinoma (CCOC) is a rare and hard-to-diagnose tumor first described by Hansen et al. in 1985. CCOC is associated with aggressive clinical behavior, metastasis, low survival rate, and difficulty in diagnosis. <h3>Objective</h3> In this study we present clinicopathologic and immunohistochemical features of 3 new cases of CCOC and summarize the features of currently published cases in order to enhance the diagnosis. <h3>Methods</h3> A search was performed with keywords "CCOC" and "clear cell odontogenic carcinoma" using the PubMed, Scopus, and Science Direct databases from 1985 to 2019. <h3>Results</h3> A total of 124 cases of CCOC were reported in literature through the end of 2019. CCOC is frequently seen in the fifth decade, with a mean age of 55.2 years. It occurs in the mandible 3 times more often than in the maxilla and has significant female predilection (61.3%). We analyzed 3 new cases, 2 female patients and 1 male patient, with a mean age of 56.6 years. Immunohistochemical analysis revealed positive immunoreactivity to EMA, CK7, CK14, CKAE1/AE3, P63, and HMW-CK and negative result for CD10, vimentin, and S100. <h3>Conclusions</h3> Considering reported cases we cannot say that CCOC is rare but we are still facing a great challenge in diagnosis of this tumor owing to its microscopic similarity to other clear cell tumors. Further immunohistochemical or gene expression analyses are needed to distinguish CCOC from other oral cancers.