Desmoplastic ameloblastoma(DA) is histologically characterized by extensive stromal collagenization or desmoplasia. ln this study, anti-cytokeratin 8/18, 13, 19 for pathogenesis as well as anti-PCNA for cellular proliferation, were used to det ect the expression of these proteins in the desmoplastic ameloblastoma Basal layers of tumor nest were negatively stained by CKl3, while suprabasal and inner cells were positive for CK13. CK8/18 and CK 19 was negatively stained in the peripheral portion of tumor nest in DA, whereas CK 8/18 was in central portion and CKl9 was positive in the su prabasal and some of central portion of the cel l nest. PCNA index of DA was 60 ::!: 14.6% to 95 ::!: 17 .2%. The peripheral tumor cells of the islets presented higher PCNA labeling index, while some cells in the central area of foll icle containing squamous like cells also presented negative PCNA labeling index. Especially tumor islands showed higher PCNA index than in main tumor mass. lt suggested that desmoplastic ameloblastoma might be composed of many different tumor cell types‘ and have hi gher pr이 ife r a ting activity in tumor islands of the desmoplastic stroma

• 이종헌(단국대학교 치과대학 구강병리학교실) | Chong Heon Lee Correspondence