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.

Figure 2 After receiving chemotherapy, immediately before pembrolizumab. A: Upper gastrointestinal endoscopy showed a mass in the descending duodenum with numerous violaceous necrotic tissue and blood clots on the surface; B: Computed tomography (CT) showed a duodenal mass with possible retroperitoneal lymph node metastasis; C: CT showed dilated right renal pelvis and abdominal ureter.

Figure 3 After receiving pembrolizumab. A: After receiving 2 cycles of pembrolizumab. computed tomography (CT) showed that the duodenal mass was significantly smaller than before; B and C: After receiving pembrolizumab for 2 years. Positron emission tomography/CT showed low density at the lateral pancreatic head attached to the duodenum and no increase in metabolism; D and E: After receiving 4 years of pembrolizumab. CT revealed no thickening of the duodenal wall (D). Upper gastrointestinal endoscopy showed smooth mucosa in the descending duodenum (E).