Accuracy of Fine needle aspiration cytology in diagnosis of salivary gland lesions: A study with histologic comparison

Abstract

Abstract Background: Fine needle aspiration cytology (FNAC) is a sensitive and specific and yet an economically effective technique for diagnosis of salivary gland lesions. FNAC of salivary glands has achieved a pivotal role in the diagnosis and management of salivary gland lesions since its induction by Stewart et al in 1933. However, it has always been under scrutiny when compared to histopathology. Histopathology of salivary gland lesions is still the final method to establish diagnosis and predicting prognosis in these lesions. Methods: A retrospetive observational study of 156 patients with excisional/incisional biopsy of salivary gland lesions was done from september 2015 to May 2019. For 60 patients presurgical FNAC was done in our hospital. Cases with histopathological correlation were included in calculating diagnostic accuracy. The cytological findings were correlated with that of the histopathological diagnosis to obtain the accuracy of the cytological diagnosis. The parameters of diagnostic validity of the cytological technique in terms of sensitivity, specificity and accuracy. Results: Study population included patients of age group ranging from 5-78 years. In the present study out of 156 lesions, 77 (49.4%) were more common in the parotid gland. These were followed by submandibular gland 69 (44.2%) and 5 cases (3.2%) occurred in the minor salivary glands. Salivary gland lesions were classified into 3 diagnostic classes: Non-neoplastic lesions 34(21.8%), benign lesions 78(50%), and malignant lesions 44(28.2%). PA and MEC were the commonest benign and malignant entity respectively. Histopathological correlations were available in 60 cases with 22 cases being the malignant lesions. In the present study, the specificity and the sensitivity were found to be 73% and 90 % respectively. Conclusions: Fine Needle Aspiration Cytology is thus a safe, reliable, quick, convenient and accurate method of diagnosis and should be considered as one of the first line of investigations in the evaluation of salivary gland lesions. However, the accuracy of FNAC can be improved by using standard reporting and adding subspecialty to our department. Keywords: Diagnostic accuracy, FNAC,Mucoepidermoid carcinoma, Pleomorphic adenoma, Salivary gland lesions, sensitivity, specificity.