Spontaneous colonic transection following pathologic complete response to pembrolizumab in high microsatellite instability colorectal cancer: A case report and review of literature

Figure 1 Serial fluorodeoxyglucose positron emission tomography-computed tomography. A: Baseline imaging showed intense fluorodeoxyglucose uptake in the hepatic flexure of the colon, multiple hypermetabolic liver lesions, and suspected peritoneal involvement; B: After 7 months of pembrolizumab treatment, a marked reduction in fluorodeoxyglucose uptake at the primary site and metastatic lesions was observed, indicating a significant treatment response; C: After completion of pembrolizumab treatment, complete resolution of prior hypermetabolic activity at the primary tumor site was observed. A new focal uptake was seen near the stoma and gallbladder bed, suggestive of either post-treatment inflammation or possible recurrence. The primary tumor site is marked with a yellow circle, and the stoma location is indicated by a orange arrow.