Fig. 2.

Pathological findings. (A) Hematoxylin-Eosin staining revealed that relatively enlarged malignant cells focally proliferated. Yellow arrows indicate mitotic figures. Black arrows indicate the lymphocytes infiltration. (B) The tumor cells were positive for TTF-1 (B) but negative for p40 (C). (D) PD-L1 22C3 PharmDx revealed that the tumor cells were strong positive for PD-L1 (tumor proportion score: 95%). Bars indicate 100 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)