Figure 1

Tumour budding, defined as the presence of isolated single cells or small clusters of cells (composed of fewer than five cells), in a case with no increase of inflammatory cells at the invasive tumour margin, illustrated in serial sections stained with haematoxylin and eosin ( A ; original × 100) and anti-cytokeratin immunohistochemistry ( B ; original × 100). Marked peritumoural inflammation, leading to the presence of isolated cancer cells due to destruction of invading cancer cell islets, is shown in serial sections stained with haematoxylin and eosin (C; original × 100) and anti-cytokeratin immunohistochemistry (D; original × 100).