Although vimentin is widely recognized as a mesenchymal marker, its expression in epithelial cells has been reported in several physiological and pathological conditions. The aim of this study was to investigate the immunoreactivity of vimentin in the epithelial component of benign odontogenic tumors. Immunohistochemistry for vimentin was performed in a total of 28 benign odontogenic tumors consisting of 11 WNT pathway-altered odontogenic tumors (WNT-OTs), 12 ameloblastomas, and 5 adenomatoid odontogenic tumors. All WNT-OTs (11/11), including calcifying odontogenic cyst, dentinogenic ghost cell tumor, and adenoid ameloblastoma, were focally positive for vimentin. Specifically, clear cells in close proximity to dentinoid were consistently positive, a subset of ghost cells were positive with varying degrees of intensity, but morular structures were negative. Two thirds of ameloblastomas (8/12) were focally positive for vimentin, more frequently in peripheral cells or the basal layer than in central cells or the upper layers, respectively. All adenomatoid odontogenic tumors (5/5) were focally positive for vimentin, especially in peripheral anastomosing strands and some cells adjacent to calcifications. Vimentin expression in epithelial cells is a common feature of benign odontogenic tumors. The intratumoral localization of vimentin in WNT-OTs may provide insights into the nature of their histologic components.

• 오규영(단국대학교 치과대학 구강병리학교실, 서울대학교치과병원 구강병리과) | Kyu-Young Oh (Department of Oral Pathology, College of Dentistry, Dankook University, Cheonan, Republic of Korea, Department of Oral Pathology, Seoul National University Dental Hospital, Seoul, Republic of Korea) Corresponding author