2nd Ed Milan Salivary

Second Edition of the Milan System for Reporting Salivary Gland Cytopathology

Authors: Esther Diana Rossi, MD, PhD et al.Published: July 2023

Introduction

The Milan System for Reporting Salivary Gland Cytopathology (MSRSGC) is a comprehensive framework that organizes fine-needle aspiration (FNA) cytopathology reports. Its primary aim is to enhance diagnostic clarity and improve patient management in the context of salivary gland lesions. The inaugural edition was released in February 2018, marking a significant milestone in the establishment of standardized reporting practices for salivary gland lesions.

Key Advances Noted in Second Edition:

  • Refined risks of malignancy (ROM) based on extensive recent studies, providing more accurate prognostic information.

  • An innovative chapter dedicated to imaging techniques for the thorough evaluation of salivary gland pathologies, emphasizing the integration of imaging in clinical practice.

  • Important updates in ancillary testing procedures, ensuring that nomenclature is current and aligned with leading scientific advancements.

  • A practical application guide outlining the role of ancillary markers in diagnostic processes, enabling clinicians to make informed decisions based on cytology findings.

Goals of the MSRSGC

The overarching objective of the MSRSGC is to create a robust linkage between defined diagnostic categories, risks of malignancy, and clinical management algorithms underpinned by solid evidence. More than 200 supporting studies validate the importance and effectiveness of the MSRSGC in the clinical setting.

Diagnostic Categories in MSRSGC

Categories Overview

  • Non-Diagnostic:Refers to inadequate samples that cannot be classified.ROM: 15%.

  • Non-Neoplastic:Comprises a wide range of inflammatory and hyperplastic lesions that do not present atypia.ROM: 11%.

  • Atypia of Undetermined Significance (AUS):Represents samples with atypical features in which a definitive diagnosis cannot be established.ROM: 30%.

  • Neoplasm:Subdivided into:A) Benign Neoplasm (e.g., pleomorphic adenoma, ROM <3%)B) Salivary Gland Neoplasm of Uncertain Malignant Potential (SUMP), ROM: 35%.

  • Suspicious for Malignancy:Indicates samples that are suggestive of malignancy but are not definitively diagnostic.ROM: 83%.

  • Malignant:Includes definitive indicators of malignancy, characterized by a ROM: >98%.

Key Updates from Each Chapter

  • Chapter 1: Introduction to the MSRSGCThis chapter discusses the backdrop of salivary gland pathology, emphasizing that salivary gland neoplasms (SGNs) account for 3-10% of head and neck tumors, with a notable predominance in the parotid gland.

  • Chapter 2: Non-DiagnosticHighlights the significance of FNA sample quality, addressing how compromised sample quality can lead to non-diagnostic results and ultimately impact patient outcomes.

  • Chapter 3: Non-NeoplasticBroadly addresses lesions that lack atypical features, emphasizing the need for clinical follow-ups to prevent overlooking potentially neoplastic conditions.

  • Chapter 4: Atypia of Undetermined Significance (AUS)This category plays a crucial role in mitigating false negative and positive results through the systematic classification of atypical cases, thereby enhancing the diagnostic process.

  • Chapter 5: Neoplasm CategoryProvides clarity on benign neoplasms and distinct cases that do not fit neatly into benign or malignant categories, revealing the complexities of salivary gland neoplasms.

  • Chapter 6: Suspicious for MalignancyOffers a refined ROM estimation of 83%, illustrating the inherent challenges associated with making definitive malignancy diagnoses.

  • Chapter 7: MalignantDiscusses detailed cytological features, aiding in the differential diagnosis of various malignancies affecting salivary glands.

  • Chapter 8: Ancillary StudiesEmphasizes a judicious approach to ancillary testing, providing guidelines for the integration of new molecular tests to enhance diagnosis reliability.

  • Chapter 9: Imaging of Salivary GlandsEngages with imaging techniques applicable to diagnosing salivary gland effusions and lesions, reinforcing the role of imaging in clinical decision-making.

  • Chapter 10: Clinical ManagementProposes algorithmic management strategies rooted in MSRSGC findings and relevant imaging, guiding clinicians in patient care.

  • Chapter 11: Histologic ConsiderationsProvides in-depth insights into cytology-histology correlations and discussions on the histological characteristics of salivary gland tumors as classified under WHO nomenclature.

Conclusions

The revised 2023 edition of the MSRSGC aims to significantly enhance diagnostic accuracy and clinical management strategies concerning salivary gland lesions. Through detailed guidelines, refined diagnostic categories, and the integration of ancillary testing, it positions itself as a vital tool for clinicians in the field of cytopathology.

Appendices and Author Contributions

The collaboration on this edition involved numerous expert contributions from pathologists and cytopathologists globally, striving for practical advancements and the continuous improvement of practices in this specialized field.