Table 1. Histopathologic characteristics of early colorectal carcinoma by macroscopic type.
| Parameter | Polypoid type (type I) | Nonpolypoid (superficial) type (type II) | |||
|---|---|---|---|---|---|
| Total | IIa | IIa+IIc | IIc+IIa |
|
|
| Incidence | |||||
|
Ca-m |
503 (78%) | 140 (22%) | 100 (16%) | 27 (4%) | 13 (2%) |
|
Ca-sm |
302 (73%) | 112 (27%) | 47 (11%) | 40 (10%) | 25 (6%) |
| Average size (mm) | |||||
| Ca-m | 21.9 ± 17.6 | 12.6 ± 7.0 | 12.2 ± 7.9 | 13.8 ± 8.0 | 14.0 ± 6.0 |
| Ca-sm | 24.6 ± 13.5 | 14.2 ± 6.6 | 13.5 ± 6.1 | 14.0 ± 5.3 | 14.5 ± 7.3 |
| Histologic grade | |||||
| Well differentiated | 756 (93.9%) | 234 (92.9%) | 134 (91.2%) | 64 (95.5%) | 36 (94.7%) |
| Moderately differentiated | 46 (5.7%) | 14 (5.6%) | 11 (7.5%) | 1 (1.5%) | 2 (5.3%) |
| Poorly differentiated | 3 (0.4%) | 4 (1.5%) | 2 (1.3%) | 2 (3.0%) | 0 |
| Rate of sm invasion | |||||
| Total | 302/805 (38%) | 112/252 (44%) | 47/147 (32%) | 40/67 (60%) | 25/38 (66%) |
| ≤5 mm | 1/26 (4%) | 7/28 (25%) | 4/23 (17%) | 2/4 (50%) | 1/1 (100%) |
| <10 mm | 13/114 (11%) | 23/77 (30%) | 13/53 (25%) | 6/7 (35%) | 4/7 (57%) |
| <20 mm | 117/401 (29%) | 90/204 (44%) | 38/122 (31%) | 32/54 (59%) | 20/28 (71%) |
| Rate of residual adenoma | 425/503 (85%) | 78/140 (56%) | 64/100 (64%) | 14/27 (52%) | 0/13 (0%) |
| Lymph node metastasis | 18/166 (11%) | 4/48 (8%) | 2/20 (10%) | 1/16 (6%) | 1/15 (7%) |
|