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Abstract

Parotid gland tumors present with diverse histopathological profiles, making accurate preoperative diagnosis essential for appropriate management. Fine Needle Aspiration Cytology (FNAC) provides a minimally invasive technique to differentiate between benign and malignant lesions. Objectives: To evaluate the diagnostic accuracy of ultrasound-guided FNAC, categorized using the Milan System, in parotid gland masses by correlating cytological findings with final histopathological diagnoses. Methods: A prospective observational study was conducted over 12 months, involving 100 patients with clinically suspected parotid gland tumors at a tertiary care center. Patients were enrolled based on predefined inclusion and exclusion criteria. Ultrasound-guided FNAC was performed using 22-gauge needles, and aspirates were categorized per the Milan System. All participants subsequently underwent parotidectomy, and histopathology was used as the reference standard. Data analysis was conducted using SPSS version 26.0 to determine sensitivity, specificity, predictive values, and overall diagnostic accuracy. Results: Among the 100 cases, FNAC classified 48 as benign, 12 as malignant, and 5 as non-diagnostic. The most frequent benign and malignant tumors were pleomorphic adenoma (41%) and mucoepidermoid carcinoma (14%), respectively. FNAC demonstrated a sensitivity of 90.4%, specificity of 96.1%, positive predictive value (PPV) of 92.3%, negative predictive value (NPV) of 94.8%, and an overall accuracy of 93.5%. The highest diagnostic concordance was observed in Milan categories IVa and VI. Conclusions: It was concluded that FNAC, when guided by ultrasound and interpreted through the Milan System, demonstrates high diagnostic accuracy for parotid masses. It is a cost-effective first-line diagnostic tool, especially beneficial in resource-limited settings.