Eosinophilic cells associated with BRAF mutation in borderline serous ovarian tumors

Objective. To define the diagnostic value of eosinophilic cells for the detection of BRAF-mutated serous borderline ovarian tumors. Material and methods. The study included 42 cases of serous borderline ovarian tumor, each of which was analyzed by 3 pathologists for the presence of eosinophilic cells. Genetic profiling using Sanger sequencing was performed to identify the BRAFV600E mutation. Comparisons between two groups were performed using the Mann-Whitney test, Fisher’s exact test. Fleiss’s kappa was used to assess the interobserver agreement. To assess the diagnostic value of eosinophilic cells, sensitivity and specificity were assessed. Results. According to the results of a genetic study, the BRAFV600Emutation was found in 19 of 42 tumors. When analyzing interobserver agreement, the Fleiss’s kappa values allowed us to determine the reliability of the test as sufficient (ϰ=0.7). The sensitivity and specificity for predicting BRAFV600Emutation for eosinophilic cells were 78.9% and 91.3%, respectively. Patients with the BRAFV600E mutation were significantly younger than patients without it. Thus, the average age of patients in the group with the BRAFV600E mutation was 33.6±15.6 years, while in the group of tumors without the mutation the average age of patients was 43.9±12.7 years (p=0.002). Non-invasive implants were less frequently found in tumors with the BRAFV600E mutation compared to tumors without the mutation: 11.76% (2/17) versus 33.3% (6/18), respectively, but these differences were not statistically significant (p=0.228). Conclusion. Eosinophilic cells in ovarian serous borderline tumors may sufficiently reflect the BRAFV600E mutation, thereby correlating with disease prognosis (low risk of progression to low-grade serous carcinoma).