A >30-cm circumferential rectal laterally spreading tumor treated with multitunnel endoscopic submucosal dissection and suturing.

Background and Aims: Laterally spreading tumors (LSTs) located in the colon and rectum are lesions with malignant potential and present significant diagnostic and therapeutic challenges, particularly when they reach large sizes. In this case, we present the treatment of a >30-cm circumferential rectal LST using multitunnel endoscopic submucosal dissection (ESD) combined with suturing. Methods: A 51-year-old female patient underwent colonoscopic evaluation, which revealed a granular-type LST extending circumferentially from the fourth centimeter of the rectum to approximately 15 cm proximally. With the patient under general anesthesia, ESD was performed using the multitunnel technique, followed by full-thickness endoscopic suturing. The procedure was successfully completed. Results: The lesion was resected en bloc (324 × 214 mm). Histopathologic examination revealed a tubulovillous adenoma with high-grade dysplasia and clear resection margins. The patient was discharged without any reported adverse events. No recurrence or stricture was observed during 24 months of follow-up. Conclusions: The multitunnel ESD and full-thickness suturing technique is an effective, safe, and function-preserving approach for large circumferential rectal LSTs. We believe that this strategy contributes to both curative resection and the prevention of adverse events such as stricture and bleeding.