Critical appraisal of histologic grading for mucoepidermoid carcinoma of salivary gland: Is an objective prognostic 2-tiered grading system possible? Journal Article


Authors: Xu, B.; Alzumaili, B.; Furlan, K. C.; Martinez, G. H.; Cohen, M.; Ganly, I.; Ghossein, R. A.; Katabi, N.
Article Title: Critical appraisal of histologic grading for mucoepidermoid carcinoma of salivary gland: Is an objective prognostic 2-tiered grading system possible?
Abstract: Multiple 3-tiered grading systems exist for mucoepidermoid carcinoma (MEC), leading to controversial results on the frequency and prognostic values of each grade. We aimed to identify prognostic histologic factors and to evaluate grading schemes in this retrospective study of 262 resected primary head and neck MECs. The rate of nodal metastasis was 8.4%. Large tumor size, tumor fibrosis, infiltrative border, lymphovascular invasion, perineural invasion, atypical mitosis, mitotic index (MI) ≥4/2 mm2(4/10 HPFs), necrosis, and pT4 stage were associated with increased risk of nodal metastasis. The 5-year recurrence-free survival (RFS) was 95%. Significant prognostic factors for RFS included infiltrative border, tumor-associated lymphoid stroma, architectural patterns (macrocystic, microcystic, and noncystic), anaplasia, atypical mitosis, MI, necrosis, lymphovascular invasion, margin, pT stage, and tumor size. Nuclear anaplasia, high mitotic rate, and ≥25% microcystic component were significant independent prognostic factors on multivariate survival analysis. There was no significant difference between low-grade (LG) and intermediate-grade (IG) MECs in terms of risk of nodal metastasis and outcomes using all 4 known grading systems. Rather, high-grade MEC was consistently associated with an increased risk of nodal metastasis at presentation and decreased RFS and distant metastasis-free survival (DMFS) compared with the LG/IG MECs. We therefore recommend simplifying MEC grading to a 2-tiered grading scheme using MI and/or tumor necrosis. Using a 2-tiered grading, high-grade histology independently predict RFS, and is associated with a 25% risk of nodal metastasis, a 5-year RFS of 76%, and a 5-year DMFS of 76%, whereas LG MEC has a nodal metastasis rate of 7.0%, 5-year RFS of 97% and 5-year DMFS of 99%. © 2023 Lippincott Williams and Wilkins. All rights reserved.
Keywords: histologic grade; mucoepidermoid carcinoma; prognosis; maml2
Journal Title: American Journal of Surgical Pathology
Volume: 47
Issue: 11
ISSN: 0147-5185
Publisher: Lippincott Williams & Wilkins  
Date Published: 2023-11-01
Start Page: 1219
End Page: 1229
Language: English
DOI: 10.1097/pas.0000000000002120
PUBMED: 37694548
PROVIDER: scopus
PMCID: PMC11198890
DOI/URL:
Notes: The MSK Cancer Center Support Grant (P30 CA008748) is acknowledged in the PDF -- Corresponding author is MSK author: Bin Xu -- Source: Scopus
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MSK Authors
  1. Ronald A Ghossein
    486 Ghossein
  2. Nora Katabi
    306 Katabi
  3. Ian Ganly
    432 Ganly
  4. Bin   Xu
    230 Xu
  5. Marc A Cohen
    137 Cohen