Descending duodenal adenocarcinoma treated with pembrolizumab resulting in complete clinical response: A case report and literature review

Figure 1 Before receiving chemotherapy. A: Upper gastrointestinal endoscopy showed a mass in the descending duodenum with bleeding; B: Hematoxylin-eosin staining showed adenocarcinoma; C and D: Positron emission tomography/computed tomography examination showed uptake of 18F-fluorodeoxyglucose in the descending and horizontal segments of the duodenum, around the intestinal wall, and retroperitoneum.