Abstract
Introduction: Small biopsies obtained by bronchoscopy are commonly used for diagnosis of lung malignancies. The emergence of treatments for lung carcinoma with differential efficacy and toxicity between subtypes has highlighted the importance of specific pathologic subtyping. The use of immunohistochemistry (IHC) has been well documented as an important ancillary tool in sub classifying lung carcinomas.
Objectives: This study is aimed to assess the expression of a panel 3 IHC markers - CK5/6, p63 and TTF-1, in 39 cases of lung carcinomas
Materials & Methods: This was a cross sectional study done over a period of 18 months in bronchial biopsy specimens of histologically proven lung carcinoma
Observations: It was observed that CK5/6 and p63 were 100% senisitive and specific for squamous cell carcinomas, if unquantified reactivities were consiered the specificity of p63 reduced to 83% and TTF-1 had 100% sensitivity and specificity in diagnosing adenocarcinoma, but if diffuse TTF-1 positivity was considered the sensitivity reduced to 66.6%.
TTF-1/p63 immuno profile showed no overlap when squamous cell carcinomas and small cell lung carcinomas were compared.
Conclusion: 3 panel IHC markers, CK5/6, p63 and TTF-1 when used together and interpreted correctly can be of help for the final diagnosis even in cases in which the morphology is unclear.
Keywords: Immunohistochemistry; CK5/6; p63; TTF-1; Squamous cell carcinoma; Adenocarcinoma; Small cell carcinoma.
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Corresponding Author
C R. Jyothi
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