Rapid On‐Site Evaluation in Ultrasound‐Guided Fine‐Needle Aspiration Biopsy of Parotid Gland Lesions

Objectives To investigate the contribution of rapid on‐site evaluation (ROSE) to the diagnostic accuracy of ultrasound‐guided fine‐needle aspiration biopsy (FNAB) in parotid gland lesions. Methods In this single‐center retrospective study, 589 parotid gland lesions evaluated between January 2012 and September 2022 were included. All procedures were performed under ultrasound guidance by interventional radiologists with more than 15 years of experience, using 20‐gauge fine‐needle aspiration needles. ROSE was performed by a cytopathologist with more than 20 years of experience. Cytological results were classified as diagnostic, suspicious, indeterminate, or non‐diagnostic. For patients who underwent surgery, postoperative histopathological diagnoses were compared with cytopathological findings. Results Among 589 lesions, 504 (85.6%) were benign and 85 (14.4%) were malignant. The most common benign lesions were Warthin tumor (33.6%) and pleomorphic adenoma (26.1%). FNAB results were diagnostic in 541 lesions (91.9%), suspicious in 38 (6.5%), indeterminate in 8 (1.4%), and non‐diagnostic in only 2 (0.3%). Among the 284 patients who underwent surgical resection, ROSE‐guided FNAB cytology was concordant with postoperative histopathology in 278 (97.9%). Conclusion ROSE‐guided FNAB represents a highly accurate, minimally invasive diagnostic strategy for parotid gland lesions, yielding definitive cytological results in a single procedure while substantially reducing the need for repeat sampling or more invasive diagnostic approaches.