Risk of malignancy in "atypia of undetermined significance" category of salivary gland fine-needle aspiration: A bi-institutional experience.

Background: Many prior institutional and multi-institutional studies have applied the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) retrospectively to their specimens to determine the risk of malignancy (ROM) of each category. Most of these studies focused on general assessment of the system and risk classification. However, there seems to be less focus on the category of atypia of undetermined significance (AUS) that could be attributed to the low number of cases that could fit into this category.

Application of the Milan System for Reporting Salivary Gland Cytopathology: A Retrospective 12-Year Bi-institutional Study.

Objectives: Multi-institutional studies are required for the validation of the Milan System for Reporting Salivary Gland Cytopathology (MSRSGC).

Methods: A total of 1,560 fine-needle aspirations of the salivary glands were retrieved from two institutions for a 12-year period. The diagnoses were reclassified based on the MSRSGC.

Subtyping salivary gland neoplasm of uncertain malignant potential based on cell type demonstrates differential risk of malignancy.

Background: The newly unveiled Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) has proposed salivary gland neoplasm of uncertain malignant potential (SUMP) as an indeterminate category. The category is reserved for fine-needle aspiration (FNA) cases that are diagnostic of a salivary gland neoplasm but cannot be further designated as a specific tumor type. The objective of the current study was to evaluate the clinical utility of subtyping SUMP cases based on different cell types.