Background: Laterally spreading tumors (LSTs) are being increasingly reported nowadays in Japan and the western countries with the application of magnification chromoendoscopy. The aim of this study was to analyze the clinicopathologic features of LSTs and to assess the outcome and safety of endoscopic mucosal resection (EMR) in China.
Patients and methods: One hundred nine patients with LSTs who underwent magnification chromoendoscopy were studied retrospectively. Clinicopathological features of 111 LSTs were analyzed. The efficacy and safety of EMR was assessed in 79 LSTs based on the outcome of follow-up colonoscopy and resection-related complications.
Results: A total of 111 LSTs were diagnosed in 109 patients, including 89 (80%) laterally spreading tumor-granular (LST-G) type and 22 (20%) laterally spreading tumor-non-granular (LST-NG) type. There was significant difference in the dominant pit pattern between LST-G type and LST-NG type (p < 0.001). Type IV pit pattern (62%) was the main crypt pattern in LST-G type; whereas, type IIIL (50%) and type V pit pattern (36%) were predominant crypt patterns in LST-NG type. EMR was performed for 103 lesions. Six of the nine lesions with type V(I) pit pattern were completely resected by EMR. Eleven (14%) local recurrent lesions were detected in 79 follow-up lesions and were treated successfully during the follow-up.
Conclusions: The type of dominant pit pattern was different between LST-G type and LST-NG type. Many LSTs with a type V(I) pit pattern can be completely resected by EMR. EMR technique is a safe and efficacious treatment method for LST.