Detection of BRAF Mutation in Metastatic Melanoma Utilizing Cell-Transferred Cytological Smears

Abstract

Objectives: Fine-needle aspiration (FNA) is frequently used to diagnose metastatic melanoma. In this study, we validated the use of cell-transferred cytological smears for BRAF molecular testing. Study Design: We conducted a search of our laboratory information system for the period 2011-2013 in order to identify surgical pathology cases of either primary or metastatic melanomas in which BRAF mutation analyses had already been performed. Thirty FNA cases with diagnoses of metastatic melanoma from the same patients were identified. Direct smears from each FNA case were selected for mutation analyses using the cell transfer technique. Results: Mutation analyses were successfully performed on 28 of 30 FNA cases (93%) using the cell-transferred cytological smears. In 25 cases (8 BRAF mutations and 17 BRAF wild types), there was 100% agreement for the BRAF mutation between the cell-transferred cytological smears and the formalin-fixed paraffin-embedded tissues. Three FNA cases showed BRAF mutations that had not been detected in the correlated surgical specimens which were tested twice, and 2 cases failed to work. Conclusions: Cell-transferred cytological smears are a reliable and alternative resource for detecting BRAF mutations in metastatic melanoma.