Fig. 3

Histologic samples at different magnification of the video assisted pleural biopsy. Panel a. Hematoxylin-eosin stain showing fragments of unremarkable lung parenchyma and small pieces of tumor (20x). Panel b. Immunohistochemistry stain with chromogranin revealing a diffuse positivity among the tumor fragment. Panel c. Ki-67 staining showed a low proliferative activity (about 1%)