2025 Volume 78 Issue 7 Pages 286-291
A 70-year-old man had been diagnosed with multiple colonic polyps at a previous hospital, and was referred to our hospital for further examination and therapy. Colonoscopy revealed three adjacent 0-I lesions in the sigmoid colon, and endoscopic mucosal resection (EMR) was performed on all three. Pathological results showed that all three were submucosal invasive cancer, two of which had submucosal deep invasion and positive lymphovascular invasion, and one also contained poorly differentiated components. We considered that additional intestinal resection was indicated, and performed a laparoscopic sigmoidectomy. The resected specimen revealed a submucosal nodule 10 mm in diameter sandwiched between two EMR scars. In the submucosal nodule, the tumor consisted mainly of well- to moderately differentiated tubular adenocarcinoma with some poorly differentiated components, and was extending from the submucosa to the subserosa. There was also moderate lymphovascular invasion. Based on these results, the tumor was diagnosed as intramural metastasis of submucosal invasive cancer and EMR was performed. Intramural metastasis of colorectal cancer is rare, and its occurrence in early-stage cancer is extremely rare. We report this case with a review of the literature.
