Correlation of Fine Needle Aspiration Cytology and Histopathological Evaluation in Salivary Gland Masses: A Single Center Retrospective Study

Abstract

Aim: Fine-needle aspiration cytology (FNAC) in the preoperative diagnosis of salivary gland (SG) masses is a very fast, inexpensive, and reliable diagnostic method. In our study, the correlation of cytological-histopathological diagnosis in cases diagnosed with fine needle aspiration cytology in our clinic was investigated, and possible causes of diagnostic entrapment in discordant cases were discussed. Material and Methods: Salivary gland FNAC cases with histopathological diagnosis between 2008 and 2019 were retrospectively analyzed.The age, gender, localization of the lesion, preoperative cytology, and postoperative histopathological diagnosis of the patients were recorded. Cytology results were analyzed in 5 categories: unsatisfactory, uncategorized, benign, suspected malignancy, and malignant. Histopathology results were recorded in 2 groups benign-nonneoplastic and malignant. Statistically significant difference level was accepted as p<0.05. The validity of the cytology result according to the biopsy result was evaluated by sensitivity, specificity, positive predictive value, and negative predictive value. Results: 316 cases of salivary gland fine needle aspiration were detected. 156 (49.4%) of 316 cases had histopathological diagnosis. When calculating the cytological-histopathological diagnosis, the cases that were found to be inadequate and uncategorized by cytology were not taken into consideration. The suspected malignancy group was evaluated within the malignant category. Therefore, diagnostic agreement was calculated in 124 cases. Of these 124 cases, 116 (93.6%) cytology-histopathology diagnosis were compatible, and 8 (6.4%) were not. In our series, the overall sensitivity and specificity were 83.3% and 97.7%, respectively. The positive predictive value was 93.7% and the negative predictive value was 93.4%. The accuracy rate was calculated as 93.5%. Conclusion: In our study, high sensitivity and specificity values were determined by FNAC in accordance with the literature. It should be kept in mind that there may rarely be differences between preoperative cytological and histopathological diagnoses, possibly due to experience, method, and lesion-related limitations and pitfalls.