Malignant colorectal polyps

Table 1 Pit pattern classification

Type of lesion	Description
Type 1	Round pits
Type 2	Stellar or papillary pits
Type 3 L	Large tubular or roundish pits
Type 3 S	Small tubular or roundish pits
Type 4	Branch-like or gyrus-like pits
Type 5	Non-structural pits

Evaluation of the fine surface structure (pit pattern) of the mucosa. Lesions with type 1 and 2 pit patterns are nontumorous epithelial tissue, that is normal, inflammatory, or hyperplastic tissue. Tumorous lesions have type 3 S, 3 L, 4 and/or 5 pit patterns. Lesion 3 L and 4 are typical of the protruded type of tumor, whereas type 3 S and 5 are typical of the depressed type of tumor.