Figure 2

(A–J) Comparison of immunostaining between monoclonal antibodies 55k-2 from Dako (A) and IM20 from Novocastra (B) in the same histological field of NSCLC: both tumour cells (white triangles) and normal endothelial cells (arrows) are similarly highlighted by the two reagents with no significant differences. Squamous cell carcinomas usually show diffuse immunostaining for fascin (C), whereas horn pearls are less immunoreactive (D). Only rarely squamous cell carcinomas lack fascin expression: in these cases, immunoreactivity of endothelial cells serves as internal positive control (E). (Panels C and D represent different areas of the same squamous cell carcinoma according to the different differentiation grade, whereas panel E refers to another case of squamous cell carcinoma showing very poor differentiation). In adenocarcinomas, invasive patterns of papillary (F) and solid (G) types show commonly immunolabelling for fascin, whereas the bronchiolo-alveolar pattern, either nonmucinous or mucinous (H), is generally unreactive for fascin even when this component is present in mixed forms along with an invasive pattern of acinar type (I). Nonmucinous type, however, may show occasional immunoreactivity for fascin (J). (Panels F–J belong to different cases of adenocarcinoma). (A: 55k-2 monoclonal antibody; B—J: IM20 monoclonal antibody. All immunostains were performed with diaminobenzidine, and then counterstained with haematoxylin. Scale bars are reported in the bottom on the left of every panel.)