Please cite this article in press as: Lopes MLDdS, et al. Ameloblastic fibro-odontoma: Case report and immunohistochemical profile. J Oral Maxillofac Surg Med Pathol (2016), http://dx.doi.org/10.1016/j.ajoms.2016.07.005 ARTICLE IN PRESS G Model JOMSMP-536; No. of Pages 6 Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology xxx (2016) xxx–xxx Contents lists available at ScienceDirect Journal of Oral and Maxillofacial Surgery, Medicine, and Pathology j o ur nal ho me pa ge: www.elsevier.com/locate/jomsmp Case Report Ameloblastic fibro-odontoma: Case report and immunohistochemical profile Maria Luiza Diniz de Sousa Lopes a , Mara Luana Batista Severo a , Maurília Raquel de Souto Medeiros b , Thallys Emannuel Ferreira Clemente b , Antonio Capistrano Ferreira Nobre Neto c , Éricka Janine Dantas da Silveira a,∗ a Post Graduate Program, Oral Pathology, Federal University of Rio Grande do Norte, Natal, RN, Brazil b Department of Dentistry, Federal University of Rio Grande do Norte, Natal, RN, Brazil c Coronel Pedro Germano Center Hospital, Natal, RN, Brazil a r t i c l e i n f o Article history: Received 2 June 2016 Received in revised form 8 July 2016 Accepted 14 July 2016 Available online xxx Keywords: Ameloblastic fibro-odontoma Odontogenic tumors Immunohistochemistry Benign jaws lesions a b s t r a c t Ameloblastic fibro-odontoma (AFO) is a rare benign odontogenic tumor of epithelial and ectomesenchy- mal origin associated with formation of mineralized products of odontogenesis. This manuscript reports an AFO affecting the posterior mandible of a 10-year-old boy with detailed clinical, radiographic and histopathological evaluation. The incisional biopsy was performed which revealed strands and islands of odontogenic epithelium composed of columnar peripheral cells surrounding central region where the cells were loosely arranged, resembling the stellate reticulum of enamel organ. The mesenchymal portion consisted of numerous ovoid and stellate cells in a loose matrix, similar to dental papilla in development. At this point, the diagnosis was ameloblastic fibroma (AF). The patient underwent complete surgical excision of the lesion associated with application of Carnoy’s solution and maintenance of the first molar. The histopathological analysis established the final diagnosis of AFO, since the same histopathological characteristics of AF were observed plus enamel and dentin matrix material on close relationship with epithelial structures. Immunohistochemical panel (AE1/AE3, CK14, CK19, Vimentin, -catenin, S-100, Ki67) was performed to illustrate AFO features. Treatment of odontogenic tumors is based on the biolog- ical and clinical behavior. In general, prognosis is excellent, with rare recurrence reports and even rarer reports of malignant transformation. No recurrence or signs of other tumors have been observed in the patient for 1 year after tumor resection. © 2016 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd. All rights reserved.  1. Introduction Ameloblastic fibro-odontoma (AFO) is a rare odontogenic tumor of mixed epithelial/mesenchymal origin, comprising 1–3% of all odontogenic tumors [1]. Tumors in the head and neck rarely affect children; however, odontogenic tumors are frequent in childhood and adolescence. AFOs usually arise in the first two decades of life, with no significant gender or ethnic predilection [2,3].  Asian AOMS: Asian Association of Oral and Maxillofacial Surgeons; ASOMP: Asian Society of Oral and Maxillofacial Pathology; JSOP: Japanese Society of Oral Pathol- ogy; JSOMS: Japanese Society of Oral and Maxillofacial Surgeons; JSOM: Japanese Society of Oral Medicine; JAMI: Japanese Academy of Maxillofacial Implants. ∗ Corresponding author at: Departamento de Odontologia, Universidade Federal do Rio Grande do Norte, Av. Senador Salgado Filho, 1787, Lagoa Nova, CEP 59056-000 Natal, RN, Brazil. Tel.: +55 84 3215 4138; fax: +55 84 3215 4138. E-mail address: ericka janine@yahoo.com.br (É.J.D. da Silveira). AFO classically presents as a painless swelling in the posterior portion of maxilla or mandible and frequently is associated with unerupted teeth [3]. Therefore, AFO is often noticed in routine radiographs taken because of teeth eruption failure [4]. Diagno- sis of AFO is based on histological evidence of a biphasic tumor composed of odontogenic epithelium proliferation within a highly cellular mesenchymal tissue with a primitive appearance, but also containing tooth-like structures as enamel and dentin in different degrees of maturation throughout the tumor [5,6]. The literature describes AFO as a non-aggressive tumor gener- ally treated by conservative surgical enucleation, with occasional reports of expansive and locally destructive progression [6,7]. Immunohistochemical data concerning AFO in the current liter- ature are very limited and is a reflex because of the rarity of this lesion. The present report adds a new case of AFO with detailed immunohistochemical information and illustrates the clinical, radiological and histopathological features. http://dx.doi.org/10.1016/j.ajoms.2016.07.005 2212-5558/© 2016 Asian AOMS, ASOMP, JSOP, JSOMS, JSOM, and JAMI. Published by Elsevier Ltd. All rights reserved. 