Fig. 2

a The stratified cells show an anastomosing arborizing pattern that is rimmed by the primitive-looking cells. The stratified mucin-containing cells have clear or slate grey cytoplasm (H&E; original magnification × 20). b High-power view showing stratified mucin containing cells with an interdigitating pattern. A few benign colonic mucosal glands are seen on the left. Tumor budding is on the low end of the spectrum. (H&E; original magnification × 40). c This is a mucin-rich area with a central focus of cell breakdown and mucin extravasation. Such foci mark the beginning of the mucin component. (Mucicarmine; original magnification × 40). d Immunohistochemistry for p53 showing a wild-type pattern in the pure ISMC. (Original magnification × 40)