title: Crossed renal ectopia coexisting with nephrolithiasis in a young Nigerian man.
abstract: BACKGROUND
  Renal ectopia or ectopic kidney is a congenital anomaly in which one or both kidneys are located in an unusual position. It results from the kidney failing to ascend properly from its origin in the true pelvis. In some cases, one kidney may cross over (crossed renal ectopia) so that both kidneys are on the same side of the body. When a crossover occurs, the two kidneys may grow together and become fused (crossed fused renal ectopia). Renal ectopia is generally uncommon; its coexistence with nephrolithiasis is even rarer. Due to its variable presentations, it is usually discovered incidentally, especially when investigating patients for abdominal pain. Treatment may be conservative when renal function is preserved and no complication is associated.
  
  
  METHODS
  we highlight the unusual occurrence of renal ectopia with nephrolithiasis in a 34 year-old Nigerian businessman who presented to the renal clinic of our hospital with a three-month history of intermittent dull right flank pain radiating to the right groin. Physical examination revealed right lumbar tenderness without guarding. The rest of the examination was unremarkable. An abdominal ultrasound scan done revealed a linear calculus in the right renal collecting system but the left kidney was not visualised. An intravenous urogram (IVU) showed a crossed ectopic kidney with nephrolithiasis. The patient was treated conservatively and his kidney function has remained stable.
  
  
  CONCLUSIONS
  This case report describes the relatively uncommon finding of crossed renal ectopia associated with nephrolithiasis.
authors.affiliation: Department of Medicine, College of Medicine, University of Lagos.
authors.forename: Bello Babawale
authors.initials: BB
authors.lastname: Taslim
authors.forename: Busari Adeniyi
authors.initials: BA
authors.lastname: Abdulwasiu
authors.forename: Sheyin
authors.initials: S
authors.lastname: Olusegun
authors.forename: Amira Catherine
authors.initials: AC
authors.lastname: Oluwatoyin
authors.forename: Mabayoje Monica
authors.initials: MM
authors.lastname: Omolara
mesh_terms: D015746:Abdominal Pain / Q000209:etiology; D000328:Adult; D006801:Humans; D007668:Kidney / Q000002:abnormalities* / Q000000981:diagnostic imaging; D008297:Male; D053040:Nephrolithiasis / Q000150:complications* / Q000000981:diagnostic imaging; D014463:Ultrasonography; D014564:Urogenital Abnormalities / Q000150:complications* / Q000000981:diagnostic imaging; D014567:Urography