The role of Napsin-and Desmocollin-in classifying poorly differentiating non-small cell lung carcinoma

There is increased need for classification of non-small cell lung cancer (nsclc) into its major subtypes,adenocarcinoma (ac) and squamous cell carcinoma (scc). such a classification is enabled in poorly differentiated tumours based on routine morphology due to overlapping morphologic features. in such cases,the use of immunohistochemistry (ihc) can differentiate between the two subtypes. purpose: to test the ability of the two markers; napsin-and desmocollin-3,in differentiating poorly differentiated (ac) from poorly differentiated scc in small biopsies. patients and methods: this is a retrospective study including 60 patients who presented with pulmonary nodules. cases with biopsy specimens diagnosed as poorly differentiated non-small cell lung cancer,and had corresponding resection specimens were included. cell blocks were stained with anti napsin-a,and anti desmocollin-3. cytoplasmic immunoreactivity for both markers was considered specific. sensitivity,specificity,positive and negative predictive values,total accuracy and combined accuracy of both markers were calculated. results: napsin a showed a sensitivity of 89.3%,a specificity of 96.9%,ppv of 96.2%,npv of 91.2%,and a total accuracy of 93.3% for ac,while desmocollin-achieved 90.6% sensitivity,96.4% specificity,96.7% ppv,90% npv,and 93.3% total accuracy. both markers achieved a total accuracy of 90%. conclusion: napsin-a,and desmocollin-were sensitive and specific markers for the diagnosis of ac and scc,respectively. both markers allowed classification of 54/60 cases into either ac or scc. © 2015.