figure 1a 5x figure 1 10x
 Figure 1. H&E, 5x. Figure 2. H&E, 10x.
 figure 2 ttf1 5x

CLINICAL HISTORY:

63yo male, with a history od NHL (Diffuse large B-cell lymphoma) presented with a 25×25 mm nodule in the right upper lobe. Histopathological examination revealed squamous cell carcinoma with an adenocarcinoma component comprising <5% of the entire tumor. 

 Figure 3. TTF-1 positivity in adenocarcinoma component. Note the lack of TTF-1 positivity in adjacent squamous cells.