IMMUNOHISTOCHEMICAL APPROACH TO DIFFERENTIAL DIAGNOSIS OF NON-SMALL CELL LUNG CARCINOMA IN BRONCHOSCOPIC BIOPSY SPECIMENS

Žaklina Mijović,Ana Stefanović,Nikola Živković

doi:10.5633/amm.2016.0205

Abstract

Non-small cell lung carcinoma (NSCLC) includes squamous cell carcinoma, adeno-carcinoma and large cell carcinoma. Subtyping of NSCLC is essential for therapy. Classification of NSCLC into more specific histological subtypes is carried out by morpho-logic examination or immunohistochemistry. The aim of this study was immunohistochemical analysis of NSCLC (squamous cell carcinoma and adenocarcinoma) in bronchoscopic biopsies. Formalin-fixed, paraffin-embedded bronchoscopic mucosal samples from 40 patients with NSCLC (20 patients with squamous cell carcinoma and 20 patients with adenocarcinoma) were retrieved from pulmonary pathology archives at Center for Pathology and Pathological Anatomy, Clinical Center Nis. Serial histological sections of 4 μm thickness were stained with hematoxylin and eosin, and immunohistochemical method DAKO LSAB for TTF-1, p63, and CK5/6 antibodies. Positive immunoreactivity for p63 was found in 95% of squamous cell carcinomas (19/20), while for CK5/6 in 90% of squamous cell carcinomas (18/20), and in 5% of adenocarcinomas (1/20). In 80% of adenocarcinomas (16/20), a positive TTF-1 immuno-phenotype was found, while all squamous cell carcinomas were negative for this marker (0/20). Immunohistochemical analysis (panel p63, CK5/6 and TTF-1) is a useful ancillary tool for distinguishing squamous cell lung carcinoma from adenocarcinoma in broncho-scopic biopsy specimens.

Highlights

Lung cancer classifications by the World Health Organization (WHO) have traditionally been based on the histological characteristics of resected tumors with little guidance about diagnosis based on small biopsies
The focus has mainly been on the separation of small cell lung carcinoma (SCLC) and non-small cell lung carcinoma (NSCLC) [1]
There have been no therapeutic implications for further classification of NSCLC, so little attention has been given to the distinction of adenocarcinoma and squamous cell carcinoma

Summary

Introduction

Lung cancer classifications by the World Health Organization (WHO) have traditionally been based on the histological characteristics of resected tumors with little guidance about diagnosis based on small biopsies. The focus has mainly been on the separation of small cell lung carcinoma (SCLC) and non-small cell lung carcinoma (NSCLC) [1]. NSCLC comprises approximately 80 % of lung carcinoma. NSCLC includes several histological types, most commonly adenocarcinoma or squamowww.medfak.ni.ac.rs/amm us cell carcinoma. There have been no therapeutic implications for further classification of NSCLC, so little attention has been given to the distinction of adenocarcinoma and squamous cell carcinoma. The emergence of treatments with differential activity (e.g., pemetrexed) or limited indication (e.g., bevacizumab) in subtypes of NSCLC has placed a new emphasis on the importance of accurate subtyping [2]

Objectives

Methods

Conclusion