Salivary Gland Cytopathology Risk Stratification

Introduction to the Milan System

The Milan System for Reporting Salivary Gland Cytopathology is a standardized, evidence-based risk stratification system that categorizes salivary gland fine-needle aspiration specimens into six diagnostic categories, each with defined risk of malignancy to guide clinical management, as recommended by the American Society of Clinical Oncology 1

The Milan System consists of six hierarchical categories with progressively increasing malignancy risk, including Salivary Gland Neoplasm of Uncertain Malignant Potential (SUMP) with a risk of malignancy of 13.3-66.66%, as defined by the Milan System 1
The malignant category is subdivided into low-grade and high-grade tumors, with a risk of malignancy of 80-100%, according to the Milan System 1

Pathologists should report risk of malignancy using the Milan System as the standardized risk stratification scheme for salivary gland cytopathology, as supported by the American Society of Clinical Oncology guidelines 1
The American Society of Clinical Oncology recommends using the Milan System to guide surgical decision-making, with categories V-VII (SUMP, SM, M) requiring surgical excision with extent determined by malignancy risk 1
The Milan System enables risk-based treatment selection, with Category IV (BN) requiring conservative surgical excision, as recommended by clinical guidelines 2

False-negative rates can reach 20% even with the Milan System, necessitating correlation with clinical findings and imaging, as noted by the American Society of Clinical Oncology 1
Core needle biopsy may be necessary for deep minor salivary glands where FNA access is limited, as the Milan System was primarily validated for major salivary gland lesions, according to clinical guidelines 2