An Unusual and Protracted Course of a Haggitt 3 Malignant Polyp Recurrence.

Timely detection of colorectal cancer recurrence is paramount, as treatment of early-stage recurrence greatly improves survival and outcomes. Current guidelines outline post-resection surveillance through endoscopy, CT imaging, and tumor markers for five years; however, there is minimal data to guide follow-up beyond this. We present the case of a 60-year-old female with locoregional recurrence 15 years after endoscopic mucosal resection of a low-grade Haggit level 3 sigmoid colon polyp. Unusually the recurrence was noted as an incidental finding following investigation of an elevated alpha-fetoprotein level post liver transplant, and a retrospective review of imaging revealed a calcified sigmoid mesentery mass. While surgical pathology revealed locoregional recurrence, there was no evidence of this on surveillance and preoperative colonoscopy. Through this case, we discuss the risk factors for late recurrence of colorectal cancer whilst exploring the literature and guidelines around this subset of patients. As new guidelines are developed, it may be important to consider late recurrence and individualize follow-up regimes based on risk factors.