Fine-needle aspiration cytology in the diagnosis of parotid lesions

Fine-needle aspiration cytology guided by ultrasound imaging is a widely used diagnostic tool to evaluate neoplastic or inflammatory lesions of salivary glands. From February 2002 to February 2008 all the parotid lesions removed surgically in our Unit of Otolaryngology were reviewed. Study focused on sensitivity, specificity, accuracy, predictive values, likelihood ratios, and Kappa statistics for fine-needle aspiration cytology vs histological diagnosis in 176 cases. Fine-needle aspiration cytology sensitivity and specificity were 81% and 99%, respectively. Accuracy for malignancy was 97%, accuracy for benignity was 83%; positive and negative predictive values were 93% and 98%, respectively; likelihood ratio of positive and negative test results were 100.3 and 0.19, respectively ("positive" was used to define "malignant"). The prevalence of malignancy was 0.114. Kappa statistics for the degree of agreement between fine-needle aspiration cytology and histological results were 0.85 (95% CI = 0.71-0.99). Pre-operative fine-needle aspiration cytology diagnosis improves surgical treatment of parotid masses.