To test the ability of the two markers; Napsin-A and Desmocollin-3, in differentiating poorly differentiated (AC) from poorly differentiated SCC in small biopsies.
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.
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-3 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%.
Napsin-A, and Desmocollin-3 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.