A Case with Serrated Polyposis Syndrome Controlled by Multiple Applications of Endoscopic Mucosal Resection and Endoscopic Submucosal Dissection

BACKGROUND Serrated polyposis syndrome (SPS) is characterized by numerous hyperplastic polyps and sessile serrated adenoma/polyp (SSA/P) in the large intestine. SSA/P is known to transform into malignant lesions through the serrated pathway instead of the adenoma-carcinoma sequence. Early diagnosis with lower gastrointestinal endoscopy and early treatment are now considered to be essential. CASE REPORT We had an experience with a case of SPS to which endoscopic treatment was applied in multiple sessions. Endoscopic treatment was performed for 16 lesions in total, and the pathological findings were SSA/P for 15 and adenoma for the other lesion. We intend to continue performing endoscopic surveillance for any newly developing lesions. CONCLUSIONS SPS has a potential for malignant transformation, and issues, such as long-term prognosis and optimal therapeutic strategies, await resolution. However, multiple endoscopic treatments are useful for cases with lesions that are controllable employing this modality.