Background: Lesions arising from odontogenic tissues cover a wide spectrum, from simple cysts to benign tumors and even carcinomas. Unicystic ameloblastoma (UA), multicystic ameloblastoma (MA), and ameloblastic carcinoma (AC) are relatively common among these odontogenic lesions. Nevertheless, the exact origin of these lesions remains unclear. It is noteworthy that BRCA1/2 mutations have been identified as potential contributing factors to the onset of various cancers. The aim of the current study was to scrutinize the BRCA1/2 expression profiles in UA, MA, and AC samples.

Methods: Biopsy specimens were collected from 60 patients, with 20 samples representing each lesion, sourced from the pathology department archive of a teaching hospital from 2000 to 2019. Immunohistochemical staining was conducted on all biopsy samples. Statistical analyses were performed using the Kruskal-Wallis H test. The differences in the data were compared with Mann- Whitney U test, and P<0.05 was considered to be significant.

Results: The Kruskal-Wallis test results revealed significant differences between the examined samples in terms of the cytoplasmic expression level of the BRCA1 basal cells (P<0.001). Regarding the cytoplasmic expression of BRCA1 stellate reticulum-like cells, there was a statistically significant difference between the examined groups (P<0.001). Furthermore, the results of the Kruskal-Wallis test demonstrated a significant difference concerning the cytoplasmic expression levels of BRCA2 basal cells between the studied groups (P<0.003). Based on the Kruskal-Wallis results, significant differences were found in terms of the cytoplasmic expression level of BRCA2 stellate reticulum-like cells between the investigated samples (P<0.001). The Mann-Whitney U test compared differences between the two examined groups.

Conclusion: The findings mainly revealed the expression of BRCA1/2 at the invasive front, which is composed of the most aggressive cells. Molecular interactions in this area may affect tumor progression. BRCA1/2 mutations can be a promising future treatment option for ameloblastoma and related lesions.