Histopathological and Immunohistochemical Characteristics of the Progressive Front of Ameloblastoma

抄録

　Ameloblastoma is a slow-developing benign odontogenic tumor, but it has relatively large number of local recurrence. Ameloblastoma was classified on the basis of the morphology that predominates in the tumor itself into plexiform type, follicular type, and other subtypes, and there have been comparative histological and clinical studies that include prognosis predictions for the different types. However, there are no conclusions regarding histological patterns and tumor activities have been reached.
　The purpose of the present study was to perform a detailed investigation of the progressive front of solid/multicystic type ameloblastoma in order to search for possible prognostic factors.
　For this study, 22 cases were chosen, in whom solid/multicystic type of a ameloblastoma. Progressive fronts of the solid/multicystic type ameloblastoma were morphologically classified into six types; plexiform, follicular, basaloid cell, sheet, trabecular and polycystic types, and immunohistochemical and morphometrical comparative studies were performed.
　Proliferative activity of columnar cells was highest in basaloid cell type at 1.9%. Periostin showed moderate to strong positive reaction in columnar cells of plexiform and basaloid cell types. Columnar and stellate-reticulum-like cells of basaloid cell type showed strong positive reaction for VEGF. The highest microvessel density and microvessel area using CD105 in basaloid cell type were 48.2±24.2 and 11.4±8.6%, respectively.
　The result of this study suggested with resection of solid/multicystic type ameloblastoma, it is important the prognosis observation to base judgment on the morphology of cells in the progressive front or in the vicinity of the resected surface.