title: Immunoexpression of Ki67, proliferative cell nuclear antigen, and Bcl-2 proteins in a case of ameloblastic fibrosarcoma.
abstract: Ameloblastic fibrosarcoma (AFS), regarded as the malignant counterpart of the benign ameloblastic ﬁbroma, is an extremely rare odontogenic neoplasm with only 68 cases reported in the English literature up to 2009. It is composed of a benign odontogenic epithelium, resembling that of ameloblastoma, and a malignant mesenchymal part exhibiting features of fibrosarcoma. Due to the rarity of the lesion, little is known about its molecular pathogenesis; therefore, in the current study, we sought to evaluate the immunoexpression of Ki67, proliferative cell nuclear antigen, and Bcl-2 proteins in AFS, comparing the results obtained with its benign counterpart, as well as to report a new case of this rare entity affecting a 19-year-old female patient. The results obtained revealed that all the proteins evaluated were overexpressed in the malignant mesenchymal portion of AFS if compared with ameloblastic fibroma, suggesting that nuclear proliferative factors such as Ki67 and proliferative cell nuclear antigen, in association to histopathologic features, may be useful markers for identifying the malignancy and that, despite the lack of molecular analysis in the case reported, Bcl-2 alteration may play a role in AFS pathogenesis.
authors.affiliation: João de Barros Barreto University Hospital, Federal University of Pará, 66073-000 Pará, Brazil.
authors.forename: Hélder Antônio Rebelo
authors.initials: HA
authors.lastname: Pontes
authors.forename: Flávia Sirotheau Corrêa
authors.initials: FS
authors.lastname: Pontes
authors.forename: Brunno Santos de Freitas
authors.initials: BS
authors.lastname: Silva
authors.forename: Sérgio Elias Vieira
authors.initials: SE
authors.lastname: Cury
authors.forename: Felipe Paiva
authors.initials: FP
authors.lastname: Fonseca
authors.forename: Rodrigo Alves
authors.initials: RA
authors.lastname: Salim
authors.forename: Décio dos Santos
authors.initials: Ddos S
authors.lastname: Pinto Júnior
mesh_terms: D000328:Adult; D000565:Ameloblasts / Q000378:metabolism / Q000473:pathology; D014408:Biomarkers, Tumor / Q000378:metabolism; D003131:Combined Modality Therapy; D005260:Female; D005354:Fibrosarcoma / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism*; D008339:Mandibular Neoplasms / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D009808:Odontogenic Tumors / Q000378:metabolism* / Q000473:pathology / Q000628:therapy; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; D019394:Ki-67 Antigen; D018809:Proliferating Cell Nuclear Antigen; D019253:Proto-Oncogene Proteins c-bcl-2