Diagnostic Accuracy of Fine-Needle Aspiration for Parotid and Submandibular Gland Lesions

Abstract

Objective: To assess the diagnostic accuracy of fine-needle aspiration (FNA) of the parotid and submandibular glands.

Study design: Case series with chart review.

Setting: Tertiary referral academic center.

Subjects and methods: Retrospective analysis was performed for all parotid and submandibular gland FNAs from a single center from 2001 to 2014. There were 1283 FNAs performed for 1076 patients. Of these, 343 cases had surgical follow-up (parotid gland, n = 272; submandibular gland, n = 71). Cases were included where the patient had a preoperative FNA, followed by surgical excision. Correlation of preoperative FNA results to final surgical pathology was performed, with measures of diagnostic accuracy computed.

Results: Malignancy was identified in 29.0% of parotid tumors and 42.3% of submandibular tumors, based on final pathology. FNA was nondiagnostic due to insufficient cellularity for evaluation in 22 of 343 cases (6.4%) and indeterminate in 39 of 343 cases (11.4%). Diagnostic accuracy in the parotid and submandibular glands for distinguishing benign from malignant pathology was determined as follows, respectively: sensitivity, 75.0% and 91.3%; specificity, 95.1% and 94.1%; positive predictive value, 84.9% and 91.3%; and negative predictive value, 91.2% and 94.4%.

Conclusion: FNA has high accuracy in identifying malignancy in parotid and submandibular gland lesions when performed at a high-volume center. Preoperative FNA results provide otolaryngologists with valuable diagnostic information that may influence the surgical management of salivary gland tumors. FNA, in conjunction with cross-sectional imaging, is useful in counseling patients for a complete informed consent.

Keywords: cytopathology; fine needle aspiration; parotid gland; salivary gland; salivary tumor; sensitivity and specificity; submandibular gland.