Fig. 3

Discordant cases with the immunohistochemical assays: a 223: The case was defined as positive with the Ventana protocol but did not show relevant staining with the Dako protocol. The corresponding FISH analysis indicated an ALK rearrangement (cores and whole section). b 260: This case revealed a positive staining with the Ventana assay but was not positive according the defined cut-off of the in house Dako assay. In this case the FISH analysis did not demonstrate a rearrangement. c L608T2: This case demonstrated a positive staining with the Ventana assay, but was negative according to the Dako assay. This case was negative with FISH. d 2L834T1: This sample was positive with the Ventana assay, but negative with the Dako assay. The FISH analysis did not show a rearrangement. e L694: This case was negative according to the Ventana staining, but positive according to the Dako assay. FISH did not demonstrate a rearrangement. The scale bar in all images represents 100 μm