Agreement Between Mucicarmine-Stained Bronchial Brushing and Bronchial Biopsy in Subtyping Non-small Cell Lung Carcinoma

Background Bronchial brushing and biopsy are used for the diagnosis of lung carcinoma as most of these tumors are unresectable. Recently, the subclassification of non-small cell lung carcinoma (NSCLC) into adenocarcinoma (ADC) and squamous cell carcinoma (SCC) has become mandatory due to the emergence of targeted therapies. Due to the inherent limitations of small samples, subcategorization of a tumor is not always possible. Immunohistochemical and mucin stains are being used for this purpose, especially for tumors with poorly differentiated features. In our study, we utilized mucicarmine mucin stain to refine the differentiation of SCC and ADC on bronchial brushing and determine its agreement with bronchial biopsy. This study aimed to measure the degree of agreement between mucicarmine-stained bronchial brushing and bronchial biopsy for subtyping NSCLC into SCC and ADC. Methodology This descriptive, cross-sectional study was conducted in the pathology department of Allama Iqbal Medical College. Samples were collected by the pulmonology department of Jinnah Hospital Lahore. The study was conducted for 10 months from June 2020 to April 2021. A total of 60 cases diagnosed as NSCLC, aged between 35 and 80 years, were included in this study. After cytohistological evaluation of bronchial brushing and bronchial biopsy specimens, the agreement was deduced using kappa statistics. Results The strength of agreement between mucicarmine-stained bronchial brushing and bronchial biopsy for subtyping NSCLC into SCC and ADC was found to be substantial. Conclusions As significant agreement exists between the two modalities, mucicarmine-stained bronchial brushing can be used for a reliable and rapid categorization of NSCLC.