Diagnostic discrepancies in fine needle aspiration diagnosis of parotid gland lesions in a resource limited hilly region

The characteristic cytological features of parotid gland lesions have been well described in literatures, but there also exist cytological diagnostic pitfalls that make it difficult to form an accurate diagnosis in some cases. Aim: To evaluate the sensitivity, specificity, along with positive predictive value, negative predictive value by Cyto- histological correlation in various lesions with an emphasis on discordant cases. Materials and Methods: A retro-prospective study of 250 non- guided/palpable FNAC of suspected parotid gland enlargements were performed from 2006 to 2018 at tertiary care hospital. The cytological smears were stained with May grunwald giemsa, papanicolaou, hematoxylin eosin stains. Surgically resected specimens were received for histopathology in 103 relevant cases only. The cytologic and Histologic slides were studied, compared and correlated where ever possible and statistical analysis done. Result: Out of 250 patients male to female ratio was 1.4: 1. The different categories of salivary gland lesions included: non neoplastic, benign and malignant constituted 109,108 and 33 cases respectively. Pleomorphic adenoma and mucoepidermoid carcinoma was the commonest benign and malignant neoplasm reported in this study respectively. False negative and false positive results were mainly due to cystic and papillary lesions. The sensitivity, specificity, along with positive predictive value, negative predictive value and diagnostic accuracy of present study was 68.42%, 98.80%, 92.85%, 93.25% and93.20% respectively. Conclusion: Though palpable FNAC of the parotid gland tumors is simple, rapid and cost-effective in a developing country but rate of characterization of specific type of parotid gland tumor is lower due to overlapping cytomorphology.