[BRAF gene mutations in ameloblastic fibromas]

Ameloblastic Fibrosarcoma of the Jaw: Case Report, Genetic Profiling, and Literature Review

Ameloblastic fibrosarcoma (AFS) is considered a malignant progression resulting from dysplastic changes in an ameloblastic fibroma (AF). Both tumors are extremely rare, with only a few cases reported in the scientific literature. Notably, BRAF mutations have been identified in ameloblastomas, suggesting a connection between ameloblastic morphology and BRAF mutations, as AF is believed to be the precursor neoplasm leading to AFS. In this study, we present a case of AFS in a 25-year-old male. The tumor tissue underwent molecular analysis, specifically next-generation sequencing (NGS) using the Oncomine Comprehensive Assay v3 System. The analysis revealed pathogenic mutations in TP53 and RB genes, as well as copy number gains in NTRK1, MDM4, and BRAF. Additionally, we provide a summary of the literature's findings from the analysis of 107 previously reported AFS cases. Our findings suggest the existence of a molecularly distinct subtype, emphasizing the importance of comprehensive molecular testing for these patients.

Mixed odontogenic tumors: A review of the clinicopathological and molecular features and changes in the WHO classification

BACKGROUND

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).

AIM

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

METHODS

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.

RESULTS

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.

CONCLUSION

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

Odontogenic and Developmental Oral Lesions in Pediatric Patients

This article reviews odontogenic and developmental oral lesions encountered in the gnathic region of pediatric patients. The process of odontogenesis is discussed as it is essential to understanding the pathogenesis of odontogenic tumors. The clinical presentation, microscopic features, and prognosis are addressed for odontogenic lesions in the neonate (dental lamina cysts/gingival cysts of the newborn, congenital (granular cell) epulis of the newborn, melanotic neuroectodermal tumor, choristoma/heterotopia, cysts of foregut origin), lesions associated with unerupted/erupting teeth (hyperplastic dental follicle, eruption cyst, dentigerous cyst, odontogenic keratocyst/keratocystic odonogenic tumor, buccal bifurcation cyst/inflammatory collateral cyst) and pediatric odontogenic hamartomas and tumors (odontoma, ameloblastic fibroma, ameloblastoma, adenomatoid odontogenic tumor, primordial odontogenic tumor). Pediatric odontogenic and developmental oral lesions range from common to rare, but familiarity with these entities is essential due to the varying management implications of these diagnoses.