S3094 An Uncommon Urologic Cause of Gastric Outlet Obstruction

Abstract

Introduction: Gastrointestinal (GI) malignancies are a common cause of gastric outlet obstruction (GOO). However, the etiologic contribution of non-GI malignancies to GOO is rarely described in literature. Herein, we present a case of urothelial carcinoma of the right ureter causing GOO. Case Description/Methods: An 84-year-old woman presented with 2 months of nausea, vomiting, bloating, and abdominal pain. She had a history of urothelial carcinoma of the bladder 12 years ago, for which she underwent transurethral bladder resection and was thought to be in remission. CT with IV contrast showed GOO, severe right-sided hydronephrosis, and thickening of the mid right ureter. Upper GI series demonstrated 20 X 7 mm duodenal stenosis in the second portion of the duodenum. EGD and EUS showed duodenal deformity causing GOO, without evidence of luminal or pancreatobiliary malignancy. Duodenal biopsies were normal. In the absence of an intrinsic GI cause for GOO, urologic evaluation was then conducted. A nephrostomy tube was placed to relieve right sided hydronephrosis. This did not translate into clinical improvement of GOO and temporal parenteral nutrition was required. Cytologic evaluations of urine samples were negative for malignancy. Ureteroscopy then revealed a sessile tumor at the right mid ureter and final biopsies were consistent with high-grade invasive urothelial carcinoma. The patient underwent palliative surgical gastrojejunostomy to relieve GOO. The right ureteral cancer was invading the duodenum, causing GOO. No GI malignancy was found at the time of surgery. Discussion: GOO is rarely caused by urologic malignancies, and urologic malignancies uncommonly present with GOO. To our knowledge, this is the fourth case reporting ureteral cancer as a cause of GOO. Although rare, urothelial cancer should be recognized as a cause of GOO. This should be suspected when images reveal severe hydronephrosis and when EGD/EUS do not find GI-related etiology. Ureteral cancer can cause GOO due to severe hydronephrosis or direct duodenal invasion. Since the right ureter passes behind the second part of the duodenum in the retroperitoneum, GOO more often occurs when the right urothelial system is involved. When severe hydronephrosis is present, a nephrostomy tube may suffice to relieve GOO. When a nephrostomy tube is ineffective, direct duodenal invasion should be suspected, and palliative interventions are then necessary to relieve GOO.Figure 1.: a. Axial CT image of the upper abdomen. The two open (blue) arrows indicate visualized portions of the distended stomach. The solid (yellow) arrow shows severe hydronephrosis. b. Upper GI image. The solid yellow arrow shows the obstructed proximal duodenum. Note that contrast flows freely from the stomach into the anastomosed limb (solid white arrow) status post diverting jejunostomy c. Microscopic examination of the right ureter biopsy reveals invasive urothelial carcinoma with high grade nuclei.