AFs, AFDs, AFOs, and odontomas are lesions that almost share the same histopathological, clinical, and radiographical features this in turn results in an argument about whether they can be categorized as a separate pathological entity or as developmental stages of the same lesion. That is why some researchers consider AFs and odontomas to be the extremes while, AFDs and AFOs are intermediate stages in between them [7, 8]. Philipsen et al. supposed that AF and AFD are expressed in two forms. The neoplastic one if left more time without treatment will not mature into odontoma. The other variant is a hamartomatous lesion that has the potential to mature into an AFO and complex odontoma. Gardner has an opinion that the AFD should be referred to simply as AF [12].

In 2005, WHO classified the AFDs under AFs. The recent WHO classification (2017) and (2022) considered AFDs to be a hamartomatous process supposing that once the hard tissue is formed, they mature to form odontomas [10, 11]. However, cases have been reported with significant large growth patterns causing cortical plate perforation. Moreover, many reports of cases with malignant transformation and recurrence have been reported. Additionally, AF, AFO, and AFD harbor the same BRAF p.V600E mutation in 46%, 34%, and 69% of cases respectively [8, 13, 14].

AFD is considered is a rare mixed odontogenic tumor that arises mainly in the posterior region mandible and is usually with an unerupted molar which in accordance with the present case too. AFD is more commonly reported in males as in this case. AFD often grows with no symptoms and may reach large sizes [13].

Histologically, the tumor is characterized by epithelial and ectomesenchymal neoplastic components. The epithelial component consists of odontogenic nest or cords lined by tall ameloblastic-like cells and central stellate reticulum-like cells. The ectomesenchymal component resembles the dental lamina with dysplastic dentin deposition.

AFD could be distinguished from other similar lesion like AF and AFO by that AFD exhibit dysplastic or tubular dentin, whereas enamel matrix deposits are found in the AFO but, regarding AF there is no any type of dental hard tissue deposits [8]. In this case, microscopically, we observed long narrow cords and islands of odontogenic follicles with juxtaepithelial hyalinization. The epithelial strands resided in a primitive ectomesenchymal stroma with stellate-shaped fibroblasts exhibiting long slender cytoplasmic extensions that resembled dental papilla. The lesions exhibited non-tubular dentin entrapping cells in multiple lacunae in close relation to odontogenic epithelium resembling dentinoid. The presence of dentinoid excludes AF tumor. Additionally, there is no enamel matrix or enamel spaces, so AFO was excluded. All of these features are consistence with the AFD.

As reported by Gardner and Farquhar, in AFDs different forms of dentin could be seen such as osteodentin, dentinoid, and dentin undergoing globular mineralization [15]. All of this tissue is considered dentinal induction; however, the juxtaepithelial hyalinization is categorized as non-dentinal induction in the ecto-mesenchyme [16]. In the present case, these features are present in the form of dentenoid material, osteodentin, and juxtaepithelial hyalinization surrounding the odontogenic follicles and cords.

Since AFDs have with low recurrence rate and usually with good biological behavior a conservative approach is usually recommended for this tumor [17]. In 2012, Giraddi, G.B., and V. Garg reported an aggressive atypical AFD presented with resorption and perforation of the cortical plate which was treated radically treated [4]

Occasionally, ameloblastic fibro-dentinosarcoma arises from the malignant transformation of AFD [18]. The 2022 WHO classification of odontogenic sarcomas presented three tumors: ameloblastic fibro-sarcoma, ameloblastic fibro-dentinosarcoma, and ameloblastic fibro-odontosarcoma. They arise from the malignant transformation of the mesenchymal component while the epithelial component does not show any malignant changes. In the present case the lesion was large in size with no evidence of malignant transformation so, conservative surgical treatment was done with a follow-up of 1 year.