Ameloblastic fibromas and ameloblastic fibrosarcomas are rare odontogenic tumors, and controversy exists in the classification of cases presenting hard-tissue production: Ameloblastic fibrodentinoma (AFD) and ameloblastic fibro-odontoma (AFO). These cases are currently considered "developing odontomas" (hamartomatous lesions).

To analyze the clinicopathologic features of these lesions and discuss the changes in the 2017 World Health Organization classification.

An electronic literature search was performed in the PubMed/MEDLINE database. An electronic search of the English language literature was performed and last updated in September 2020 in the PubMed/MEDLINE database using the following terms: "ameloblastic fibroma", "ameloblastic fibrodentinoma", "ameloblastic fibro-odontoma", "ameloblastic sarcoma", "ameloblastic fibrosarcoma", "ameloblastic fibrodentinosarcoma", "ameloblastic fibroodontosarcoma" and "odontogenic carcinosarcoma". The inclusion criteria were odontogenic tumor series, case reports and systematic reviews that provided sufficient clinical, radiological and microscopic documentation to confirm the diagnosis.

The database search strategy resulted in 947 papers. Articles focusing on other topics, articles that were not in English, duplicate articles, and articles without fulfilling the inclusion criteria were excluded. Finally, 96 publications were included in this review to describe and discuss the main features of the searched entities. Several aspects of AFO and AFD, such as biological behavior, age of occurrence, amount of hard tissue, and potential for malignant transformation into odontogenic sarcomas, support the neoplastic nature in most of the reported cases. Considering the clinical, radiographic, histopathological and molecular characteristics of odontogenic lesions with hard tissue production, we suggest that these types of lesions should continue to be recognized as odontogenic tumors by maintaining the classically used terms.

This recommendation will be relevant for future clinical, microscopic, and molecular studies to better understand the biology of these interesting odontogenic tumors.

Ameloblastic fibrosarcoma (AFS) now designated as odontogenic sarcoma is a malignant odontogenic tumor characteristically composed of a benign epithelium and a malignant mesenchymal component. It can arise de novo without any preexisting lesion or it can result from the malignant transformation of ameloblastic fibroma (AF). Hereby, we report an extremely rare case of odontogenic sarcoma which was transformed from AF over a period of about 2 years. This is the first case to be reported after it has been reclassified as odontogenic sarcoma. A systematic review was also done to evaluate the studies that reported AFS arising de novo and AFS arising from AF. The objective of this study is to systematically review the studies that reported AFS arising de novo and AFS arising from AF. Articles that reported AFS arising de novo and AFS arising from AF were collected from PubMed, Medline, Embase, Cochrane, Google search and manual search. The results of the systematic review showed that six studies (46.1%) reported AFS arised de novo with no previous history of AF. Seven studies (53.84%) reported that amelobastic fibrosarcoma arised from AF. A rare case of odontogenic sarcoma transformed from AF is reported here. This is the first case report to be published on odontogenic sarcoma after the World Health Organization reclassification. AF once diagnosed should be treated immediately without any delay to avoid the chances of its malignant transformation into odontogenic sarcoma.

The purpose of the present review was to integrate the available data published on ameloblastic fibrodentinosarcoma (AFDS) and ameloblastic fibro-odontosarcoma (AFOS) into a comprehensive analysis of their clinical/radiologic features. An electronic search was undertaken in July/2017. Eligibility criteria included publications having enough clinical/radiological/histological information to confirm the diagnosis. Seventeen publications (8 AFDS, 9 AFOS) were included. The patients with the two different lesions had a similar mean age. The lesions were both more prevalent in mandibles than in maxillae, all showed bone expansion and similar rates of cortical bone perforation, tooth displacement, and locular appearance at radiological exams. Mean follow-up time was higher for AFDS, and the mean size of the lesions were larger for AFDS, although without a statistically significant difference. None of AFDS recurred, while 2 AFOS recurred. As only few cases of AFDS and AFOS have been reported, additional reports are necessary to add evidence to the study of clinical and radiologic features of these lesions.