Diagnostic accuracy of fine needle aspiration cytology in parotid gland lesions

Abstract

Background: This study aimed to estimate the fine needle aspiration cytology’s (FNAC) diagnostic accuracy in differentiating neoplastic from inflammatory lesions (Q1) and malignant from their benign counterparts (Q2). Methods: We present a retrospective case series covering a single University Hospital and six attending head and neck surgeons over eight years (January 2011 to July 2017). We concentrated on adults with clinically suspected parotid gland lesions. We offered all patients FNAC biopsy preoperatively, and the final diagnosis was established based on the findings of the final histology. The FNAC and histology results were cross-tabulated in a 2 x 2 contingency table, from which we calculated the diagnostic accuracy, sensitivity, specificity, and positive and negative predictive values. Results: From 212 consecutive patients reviewed, and after excluding thirteen cases (8 %) of valid but non-diagnostic FNAC, 161 cases (50 females and 111 males) fulfilled set eligibility criteria. The most common diagnosis was Warthin tumors (53 patients, 34 %), followed by pleomorphic adenomas (52 patients, 33.5 %). The sensitivity and specificity of FNAC in differentiating neoplastic from non-neoplastic lesions and in segregating malignant from benign conditions were estimated to be as high as 50 % and 97 %, and 98 % and 93 %, respectively. Conclusion: FNAC is moderately effective in differentiating non-neoplastic from neoplastic disease and highly accurate in selecting malignant lesions from benign ones. Although the lack of FNAC sensitivity can occasionally be problematic, it still comprises a valuable tool in salivary gland surgery. HIPPOKRATIA 2022, 26 (1):25-31.