Abstract
INTRODUCTION: Gastric outlet obstruction caused by upper tract urothelial carcinoma is rare. CASE PRESENTATION: A 78-year-old man presented to the hospital with nausea and vomiting. No hematuria was observed. Computed tomography revealed a tumor in the right renal pelvis and duodenal stenosis. Gastrojejunostomy was performed to treat the symptoms of the gastric outlet obstruction so that the patient could resume oral intake and outpatient chemotherapy. Chemotherapy was unsuccessful, and the patient died 9 months after the gastrojejunostomy. Histological assessment of an autopsy specimen revealed plasmacytoid urothelial carcinoma with direct infiltration of the duodenal wall, which caused the stenosis. CONCLUSION: Autopsy revealed a right renal pelvis cancer causing gastric outlet obstruction. Early gastrojejunostomy enabled oral intake and outpatient visits.