Ameloblastomas: a regional Latin-American multicentric study

Pathology Department, InstitutoNacional de Cancerologi´a, Me ´xico, D.F. Me´xicoAIM: To classify 163 ameloblastoma cases according tothe new WHO Classification of Odontogenic Tumours(2005) and analyse their clinical and microscopic features.METHODS: We studied the clinico-pathological featuresof 163 ameloblastoma cases from nine regional Latin-American institutions from Mexico and Guatemala.RESULTS: Ameloblastomas comprised 22.7% of allodontogenic tumours. The mean age was 41.4 years forsolid ameloblastoma (SA) and 26.3 years for unicysticameloblastoma (UA) (P < 0.001) and both sexes werealmost equally affected. The mandible was mainly af-fected for both UA and SA. The mean size was 6.2 cm forSA and 6.3 cm for UA cases. The recurrence rate was21.7% for SA and 12.6% for UA. UA was twice as morefrequent than the solid variant.CONCLUSIONS: In this study we found that UA wasfrequently misdiagnosed as SA; however, there are en-ough clinical and microscopic features that allow for anaccurate differentiation between both types of amelob-lastoma that should be recognized for surgical andprognostic purposes. In this study, SA was not found inpatients younger than 20 years, UA had a constantmyxoid stroma while mature connective tissue was morefrequently associated with the solid type.Oral Diseases (2007) 13, 303–307Keywords: odontogenic tumours; ameloblastoma; solid amelob-lastoma; unicystic ameloblastoma; mandibular tumours; maxillarytumours