2025 Volume 67 Issue 5 Pages 1090-1096
An 86-year-old man with a history of colorectal cancer surgery underwent a CS that identified a 10-mm superficial elevated lesion in the ascending colon. The lesion showed findings consistent with an open type Ⅱ pit pattern, and histopathological biopsy confirmed the diagnosis of a sessile serrated lesion (SSL). At the initial examination, multiple adenomatous polyps were detected and resected endoscopically, but the SSL was kept under surveillance. During the first follow-up at two years and one month, no significant morphological changes were observed in the SSL. However, at four years and three months, a shallow central depression was noted, raising suspicion for progression. Biopsy at this time revealed a highly differentiated adenocarcinoma, and endoscopic resection was performed. Histopathological evaluation showed well-differentiated adenocarcinoma with invasion into the submucosal layer (2,000 μm) and positive lymphatic invasion. Subsequent genetic analysis identified a BRAF mutation.
Here, we report this interesting case to speculate the growth and progression of SSL.
