Fig. 1

Routine pathological findings of the colon cancer in case 1. a Gross view shows an ulcerated tumor (surrounded by arrowheads). Scale bar: 1 cm. b The tumor invades the subserosa (arrowheads). Hematoxylin and eosin (H&E) stain. Scale bar: 2 mm. c The tumor consists mainly of an adenocarcinoma with a tubular growth pattern, but the cell aggregates with poor luminal formation are also mainly scattered in the invasive front (arrows). H&E stain. Scale bar: 400 μm. d Scattered cells are also strongly positive for pan-cytokeratin, and the changes in the shape of the tumor glands are more visible with immunostaining. Arrowheads indicate the tumor cell protrusion into the stroma. AE1/AE3 immunostain. Scale bar: 100 μm