Ameloblastic fibro-odontoma: Case report and immunohistochemical profile

Ameloblastic fibro-odontoma (AFO) is a rare benign odontogenic tumor of epithelial and ectomesenchymal 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, β-catenin, S-100, Ki67) was performed to illustrate AFO features. Treatment of odontogenic tumors is based on the biological 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.