[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 BRAF^V600E 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 BRAF^V600Emutation 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 BRAF^V600Emutation for eosinophilic cells were 78.9% and 91.3%, respectively. Patients with the BRAF^V600E mutation were significantly younger than patients without it. Thus, the average age of patients in the group with the BRAF^V600E 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 BRAF^V600E 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 BRAF^V600E mutation, thereby correlating with disease prognosis (low risk of progression to low-grade serous carcinoma).