Large-cell lung carcinoma by the 2015 WHO classification: a clinicopathologic analysis of 93 cases

Abstract

To analyze the clinicopathologic characteristics of large-cell lung carcinoma (LCC) subtypes according to the 2015 WHO classification. A total of 93 cases of LCC were identified among 1 634 cases of morphologically undifferentiated non-small cell lung carcinoma. Clinicopathologic and immunohistochemical characteristics were retrospectively reviewed. Among 93 cases of LCC, 50 cases were solid adenocarcinoma (53.8%), 21 cases were non-keratinzing squamous cell carcinoma (22.6%), 3 cases were adenosquamous carcinoma (3.2%), 8 cases were large cell carcinoma with unclear immunohistochemical features (8.6%), and 11 cases were large cell carcinoma with null immunohistochemical features (11.8%). No significant differences in clinical features were found among various immunophenotypes. The overall survival of 1, 3 and 5 years of all cases was 51.0%, 5.4% and 1.1%, respectively and the mean survival was (15.2±1.2)months. Notably the null type had the lowest survival rate of 18% in one year, significantly worse than those of solid adenocarcinoma and non-keratinzing squamous cell carcinoma. The 2015 WHO classification based on immunohistochemical phenotype replaces the morphological approach in separating poorly differentiated non-small cell lung carcinoma from the former large cell lung carcinoma. The null immunohistochemical subtype may represent a distinct subtype of undifferentiated carcinoma with the worst prognosis.