Milan Scoring System for Diagnosing Salivary Gland Lesions: Assessing the Risk of Malignancy

Abstract

Background: Salivary gland lesions encompass a wide spectrum of benign and malignant conditions, necessitating accurate preoperative diagnosis for optimal patient management. Fine-needle aspiration cytology (FNAC) is a widely used diagnostic tool; however, the variability in interpretation has led to the development of the Milan Scoring System, which stratifies lesions based on the risk of malignancy. This study evaluates the effectiveness of the Milan Scoring System in diagnosing salivary gland lesions and assessing malignancy risk.

Aim: To assess the diagnostic accuracy of the Milan Scoring System in salivary gland lesions by correlating FNAC results with final histopathological diagnoses.

Methods: 400 patient records from Madhubani Medical College and Hospital in Bihar were used in a two-year retrospective observational research. The Milan Scoring System was used to classify the FNAC data, and 362 instances had histological confirmation. SPSS version 23.0 was used for statistical analysis, which included sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV).

Results:  Of the 400 cases, 218 (54.5%) were females and 182 (45.5%) males, with a mean age of 45.6 years. FNAC categories were distributed as follows: Category 1 (7.5%), Category 2 (42.5%), Category 3 (10.5%), Category 4 (27%), Category 5 (6.5%), and Category 6 (6%). Histopathological confirmation was available in 362 cases. The Milan System demonstrated a sensitivity of 85.6%, specificity of 92.3%, PPV of 88.4%, NPV of 90.8%, and overall diagnostic accuracy of 89.5%. The risk of malignancy ranged from 1.8% in Category 2 to 91.7% in Category 6. The parotid gland was the most commonly affected site (57%).

Conclusion: The Milan Scoring System is a reliable tool for classifying salivary gland lesions, demonstrating high diagnostic accuracy and strong correlation with histopathological outcomes. Its structured approach aids in risk stratification, reducing unnecessary surgeries while ensuring timely management of malignant cases.

Recommendations: To improve the system's applicability, more prospective studies with bigger cohorts and multi-center validation are advised. Additionally, integrating molecular diagnostic techniques with FNAC may improve diagnostic precision, particularly in indeterminate (Category 3) cases.

Keywords: Salivary gland lesions, Milan Scoring System, FNAC, malignancy risk, histopathology correlation