CE- MEDICAL ILLUSTRATION ‘‘Crossed renal ectopia’’

A 76-year-old man presented with a 2-month history of progressive abdominal distension and occasional right-sided colicky pain. On the clinical examination, a ballo-table mass was found in the right abdomen. There was no guarding or rebound tenderness, and the rest of the clinical examination was unremarkable. An abdominal radiograph was unremarkable with no urinary calculus or intestinal obstruction detected. 99mTechnetium-mercap-toacetyltriglycine (MAG-3) renography was performed to exclude urinary obstruction and assess the urinary system. MAG-3 renography showed the right kidney located in the left abdomen just inferior to the left kidney with the right ureter crossing the midline and draining into the right side of the urinary bladder, suggestive of a crossed renal ectopia with right-to-left ectopia (Fig. 1, arrow)