Metachronous colorectal carcinoma with massive submucosal invasion detected by annual surveillance in a Lynch syndrome patient: a case report

BACKGROUND: Lynch syndrome is the most common form of hereditary colorectal carcinoma. It is characterized by the presence of germline mutations in DNA mismatch repair genes. Mutation carriers have a lifetime risk of developing colorectal carcinoma of approximately 80%. Current treatment guidelines recommend periodic surveillance for colorectal carcinoma in patients with Lynch syndrome. However, the optimal interval between colonoscopies has not yet been determined. CASE PRESENTATION: We describe a 54-year-old man with Lynch syndrome who was undergoing annual colonoscopy surveillance for the development of colorectal carcinoma. At 54, 57, 59, and 60 years old, a colonoscopy showed high-grade dysplasia and adenoma. Therefore, endoscopic mucosal resection was performed. At 61 years old, a colonoscopy showed metachronous colorectal carcinoma with massive submucosal invasion. He subsequently underwent laparotomy for colorectal carcinoma. CONCLUSIONS: Annual surveillance using colonoscopy can detect colorectal carcinoma at an early stage, leading to reduced mortality. However, some patients might require a laparotomy, as was the case here. More frequent colonoscopic surveillance might be necessary to avoid surgery for colorectal carcinoma in Lynch syndrome patients with multiple risk factors for interval cancer.