Subtyping of Non-Small Cell Lung Carcinomas in Bronchoscopic Biopsies: A Tertiary Care Centre Experience

摘要

The advent of promising targeted therapies against specific subtypes of Non-small Cell Lung Carcinoma (NSCLC) has made it mandatory for the pathologists to subclassify NSCLC into its subtypes, along with saving tissue for molecular studies and work closely with the radiologists and the clinicians for effective management of the cases.Aim: To subclassify NSCLC into its subtypes using routine diagnostic techniques, to study the demographic, clinical and radiological features of lung cancer in addition to performing a limited immunohistochemistry panel on bronchoscopic samples.Materials and Methods: Clinically and radiologically suspected cases of lung cancer having non-small cell morphology were subjected to cytological and histopathological examination for subtyping. A limited immunohistochemistry (IHC) panel comprising of TTF-1, Napsin A, P63 and Neural Cell Adhesion Molecule (NCAM) was used in poorly differentiated tumours for further subtyping.Results: There were 52 cases of NSCLC with an incidence rate of 1.78 per 1000 per 1.5 years. Average age of patients was 56.13 years and there was a slight male preponderance. Breathlessness (85%) was the most frequent clinical finding followed by weight loss and cough (81% each). All cases presented with solid nodule or mass lesion. Adenocarcinoma (n=46%) was the most frequent histological type followed by Squamous cell carcinoma (n=34%). Ten poorly differentiated cases were classified on IHC as follows: three cases each of NSCLC favour Adenocarcinoma and NSCLC favour Squamous cell carcinoma, two cases each of Small cell lung carcinoma and NSCLC Not Otherwise Specified (NOS).Conclusion: Using routine diagnostic methods and a limited IHC panel comprising of TTF-1, Napsin A, P63 and NCAM in biopsies, it was possible to classify all 52 cases of NSCLC as per latest classification guidelines while restricting the number of NOS cases to just two.