Correlation of Salivary Gland FNA Reporting Using the Modified Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) and Intraoperative Frozen Section Evaluation with Final Histopathology Report for Major Salivary Gland Neoplasms.

Abstract

Fine needle aspiration (FNA) is a commonly used investigation for salivary gland lesions. The modified MSRSGC was introduced to standardise the FNA reporting of major salivary gland lesions. A frozen section is also used intraoperatively for these lesions. In this retrospective study, we included all patients who were treated at our institute between January 2012 to December 2019. The FNA reports of all the patients were reclassified based on the modified MSRSGC, and the sensitivity, specificity, and positive and negative predictive values were calculated. We also assessed the indication for utilising the frozen section and correlated it with the preoperative FNA and the final histopathology report. A total of 325 patients satisfied the eligibility criteria and were included in this study. The sensitivity and specificity, positive predictive value, and negative predictive value of the modified MSRSGC were 64.18% and 91.94% and 92.27% and 63.11%, respectively. The frozen section (FS) was done in 131 patients, the commonest reason was for obtaining a primary diagnosis (n = 104,79.3%). When the FNA was type V and above the primary diagnosis was that of malignancy in the vast majority (p < 0.001, kappa 0.563). The values of the modified MSRSGC were comparable with available literature in all categories except categories I and II which were higher than what is reported in the literature. When the preoperative FNA was modified to MSRSGC V and above, the possibility of malignancy was high, and the use of FS for primary diagnosis may not add much value intraoperatively.