Revised histcpathologicacll assificatioofn o dontcgenic tumors by World Health Organization (WHO) has been published in 2005 by Internaticna Aig ency fcr Research on Cancer (IARC).In this classificaticmno, st malignant tumors are generallyc onsidered the counterpartso fbenign odontogenic tumors. Odontogenic carcinomas are classifieidn tom etastasizing (malignant) ameloblastoma, ameloblasticc arcincmas, p rimary intraosseous squamcus cellc arcinomas (sclidt ype, d erived frcm keratocystico dcntogenic tumor and derived frcm odcntogenic cysts), c learc ello dontogenic carcinoma and ghost cello dcntogenic carcinoma. Odontogenic sarcomas are ameloblasticf ibrcsarccma and amelcblasticf ibrc-odcntcsarccma B.e nign tumcrs are classifieidn tcf ollcwingf our categories; 1) odontogenic epithelium with mature, fibrous strcma without odcntogenic ectcmesenchyme, 2) odontogenic epithelium with odontogenic ectomesenchyme with or without hard tissue formation, 3) mesenchyme and/or odcntogenicectomesenchyme with or without odcntcgenic epithelium, and 4) bone-related lesions. Category 1 is composed of various types of ameloblastoma, squamous odontogenic tumor, calcifyingepitheliaold ontogenic tumor, adenomatoid odontogenic tumor, and keratocystico dontogenic tumor named odontcgenick etarccysti n previcus classificatiCcan.t egcry 2 consistso f ameloblasticf ibroma, a melcblasticf ibrcdentinoma, ameloblasticf ibro-odontoma, o dontomas, odontoameloblastoma, calcifyingc ystico dcntogenic tumor and dentinogenicg hcst cellt umcr.Both calcifyincgy stico dontogenic tumor and dentinogenicg host cellt umor were previcuslyn amed calcifyinogd cntcgenic cyst.O dcntogenic fibrcma, odcntcgenic myxcma and cementoblastcma are classifieidn to category 3. Category 4 is composed of ossifyingf ibroma, f ibrousd ysplasia, o sseous dysplasia, centralg iantc elll esicn, c herubism, aneurismal bone cysta ndsimple bone cyst.
Although odontogenic epitheliacly stsi s not included in the revised WHO's histologicacll assificatioofn o dontogenic tumors, terminologicaplr oblems of a few cystsc lassifieidn 1992 are describedi n the present paper.