A cytohistological correlation in salivary gland swelling with special reference to the proposed Milan system

Abstract

Context and background: Cytological grading of salivary gland lesion, which is a simple, cost-effective, and reproducible method, can be used as a tool for the selection of treatment modality. The proposed Milan classification establishes one guideline for reporting of salivary gland cytology and thus helps in individualized treatment and follow-up.

Aims and objectives: (1) The aims and objectives of this study were to establish the validity and reliability of the Milan classification of cytological grading in salivary gland swelling and (2) to calculate the malignancy risk.

Materials and methods: This prospective study was designed in clinically diagnosed salivary gland swelling at the Department of Pathology of a tertiary care referral hospital. Fine-needle aspiration (FNA) was done, and stained smears were examined under light microscope and cytological findings were noted according to the Milan classification. Tissue for the histopathological study was obtained in 119 cases. The previous cytological findings were compared to subsequent histopathology report.

Results: : Among 119 FNAs, 2.5% were nondiagnostic and 55.4% were nonneoplastic. While no samples were placed in the atypia of undetermined significance category, benign tumors accounted for 25.2%. About 1.7% was grouped in the salivary gland neoplasm of uncertain malignant potential, 2.5% of cases were categorized as suspicious of malignancy, and 12.6% of cases comprised as malignant tumors. Overall, malignancy risk was observed to be the highest (93.3%) in Category 6 and lowest (3.0%) in nonneoplastic category.

Conclusions: The six-tier diagnostic categories of the Milan classification scheme help in segregating patients with salivary gland lesions into the management categories of follow-up, conservative surgery, and radical surgery with/without chemotherapy.

Keywords: Fine-needle aspiration; Milan classification; histopathology; salivary glands.