Intramural recurrence without mucosal lesions after an endoscopic mucosal resection for early colorectal cancer

Advances in endoscopic instruments and techniques have enabled increased detection and removal of early colorectal cancer (ECC), which is defined as a tumor whose invasion is limited to the mucosa or submucosa. Some cases can be treated by endoscopic mucosal resection (EMR). However, local recurrence frequently occurs after an EMR for ECC. The recurrence pattern is usually intramural recurrence with a mucosal lesion at the EMR's site. We report the cases of two patients with intramural recurrence without mucosal lesions after an EMR for ECC. These cases indicate that a local recurrence after an EMR for ECC can appear as an intramural recurrence without mucosal lesions at a previous EMR site or another site, although this presentation is very unusual.