Comparative Outcomes of Fine Needle Aspiration and Core Needle Biopsy for Parotid Masses.

Abstract

To compare the diagnostic accuracy and safety of ultrasound-guided fine needle aspiration (FNA) versus core needle biopsy (CNB) for parotid masses. Retrospective cohort study. Tertiary academic medical center, 2018 to 2023. We reviewed 485 patients undergoing ultrasound-guided parotid biopsy (426 FNAs and 59 CNBs). Permanent histopathology served as the reference standard. Primary outcomes included diagnostic performance metrics for neoplasm, malignancy, and tissue-specific diagnosis. Secondary outcomes included nondiagnostic rates, complications, time to surgery, and technical factors (needle gauge, biopsy setting, and number of passes). CNB demonstrated superior sensitivity (80.0% vs 54.9%, P = .032), accuracy (86.4% vs 68.5%, P = .007), and positive predictive value (87.0% vs 56.4%, P = .01) for detecting malignancy compared to FNA. CNB had superior tissue-specific accuracy (67.8% vs 49.5%, P = .009), particularly for squamous cell carcinoma and mucoepidermoid carcinoma. FNA had a higher nondiagnostic rate (20.0% vs 5.1%, P = .004). Greater CNB accuracy correlated with ≥3 needle passes and use of 17 to 18 gauge needles. Complication rates were low and similar (3.4% CNB vs 2.1% FNA), with no facial nerve injuries or tumor seeding reported. Time to surgery was comparable (CNB 51 days vs FNA 42 days, P = .10) in cases of malignancy. CNB showed improved diagnostic accuracy and fewer nondiagnostic results than FNA for parotid masses, particularly for suspected malignancies and complex histologies, without added risk or delay. CNB should be considered in cases suspicious for malignancy or where tissue-specific diagnosis would inform operative planning.