Inter-Rater Agreement in the Interpretation of Extranodal Extension of Metastatic Squamous Cell Carcinoma-A Multi-Institutional Study.

Abstract

The purpose of this study is to assess inter-rater agreement in both diagnosis and extent of ENE in head and neck squamous cell carcinoma among head and neck pathologists. Representative slides from 50 random patients exhibiting various extents of ENE obtained from patients who had undergone neck dissection were selected and reviewed by eight head and neck pathologists across four tertiary referral head and neck institutions. Inter-rater agreement for the presence of ENE was moderate (kappa = 0.33). For minor ENE, the inter-rater agreement was slight (kappa = 0.03) and for the presence of major ENE the inter-rater agreement was also slight (kappa = 0.05). These findings of only slight to fair consistency in the histopathological diagnosis and characterization of ENE across multiple high volume tertiary Head and Neck centers suggest the imperative need for a consensus guideline among pathologists in both processing of lymph nodes and interpretation.