Cytohistological correlation of salivary gland tumours with emphasis on Milan system for reporting: A novel step towards internal quality assurance

Background: Fine needle aspiration cytology (FNAC) is a cost-effective diagnostic technique for evaluation of salivary gland lesions. But, then, cytological evaluation of salivary gland lesions also has lot of challenges. To overcome the difficulties, “The Milan system for reporting salivary gland cytopathology” (MSRSGC) was introduced for diagnosis and management and establishing the risk of malignancy (ROM) in different categories. The present study was conducted to grade the salivary gland lesions according to Milan system of reporting and to correlate with their histopathological findings. Material and Methods: The current study was conducted in the department of Pathology, Mahatma Gandhi Medical College and Research Institute, Sri Balaji Vidyapeeth, Pondicherry for a period of 5 years. Around 153 salivary gland lesions were aspirated. Salivary gland swellings were examined clinically, correlated with the details on the request forms and ultrasound findings, palpated and aspirated. The cytological features were evaluated and categorized according to Milan System for Reporting Salivary Gland Cytopathology”: Category 1: Nondiagnostic (ND); Category 2: Non-neoplastic (NN); Category 3:Atypia of undetermined significance (AUS); Category 4a: Neoplasm: benign (NB), Category 4b: Neoplasm:salivary gland neoplasm of uncertain malignant potential (SUMP); Category 5: suspicious of malignancy(SM); and Category 6: Malignant (M). They were further correlated with histopathological findings. All data were entered in MS excel sheet. Results: Total 153 cases were evaluated cytologically, and histological followup was available in 134 cases. The distribution of cases into different categories were as follows Non-Diagnsotic (2.6%), Non-Neoplastic (20.9%), Atypia of Undetermined Significance (1.9%), Neoplastic-Benign (41.1%),Salivary gland neoplasm of Uncertain Malignant Potential (0%), Suspicious of Maligancy (0%) and Malignancy (33.3 %). Risk of malignancy were