Small colorectal cancers resembling submucosal tumor with massive submucosal invasion and lymph node metastasis: A report of two cases and review of the literature

Summary Colorectal cancer resembling submucosal tumor (SMT) is very rare. We herein report two cases of small colon carcinoma resembling SMT (80-year-old female and 67-year-old male), which massively invaded into the submucosal layer and accompanied marked lymphatic invasion and lymph node metastasis. We also reviewed the reported cases of colorectal carcinoma resembling SMT (SMT-like group, n  = 70) and analyzed the clinicopathological characteristics of this group compared with typical colorectal carcinoma cases operated at our institution (control group, n  = 1723). Tumors in the SMT-like group were significantly smaller in size compared with the control group; the median diameter measured 22 mm vs. 37 mm ( P P P