title: Cystic nephroma, cystic partially differentiated nephroblastoma and cystic Wilms' tumor in children: a spectrum with therapeutic dilemmas.
abstract: BACKGROUND
  Cystic renal tumors are a diagnostic and therapeutic challenge. Cystic nephroma (CN), cystic partially differentiated nephroblastoma (CPDN) and cystic Wilms' tumor (CWT) are a spectrum with CN at the benign end, CWT at the malignant end and CPDN in the intermediate position. CN and stage 1 CPDN are often treated with surgery alone. International Society of Pediatric Oncology (SIOP) protocols for Wilms' tumor (WT) advocate preoperative chemotherapy, which may be unnecessary and potentially harmful in CN and in stage 1 CPDN. There are difficulties in differentiating the three types using imaging techniques. Therefore, controversies exist regarding the optimal treatment.
  
  
  METHODS
  We describe 6 children, who each had a postoperative diagnosis of CN, CPDN or CWT, and we retrospectively evaluate the treatment strategies.
  
  
  RESULTS
  The three types cannot be differentiated using imaging techniques, although the presence of solid components in the tumor is indicative of WT.
  
  
  CONCLUSIONS
  Surgery as first-line therapy should be seriously considered in children who have a cystic renal tumor, but further collaborative studies are needed since the distinction line between CPDN and CWT is not always clear.
authors.affiliation: Department of Pediatric Urology, Erasmus MC, Sophia Children's Hospital, Rotterdam, The Netherlands. j.vandenhoek@erasmusmc.nl
authors.forename: Joop
authors.initials: J
authors.lastname: van den Hoek
authors.forename: Ronald
authors.initials: R
authors.lastname: de Krijger
authors.forename: Kees
authors.initials: K
authors.lastname: van de Ven
authors.forename: Maarten
authors.initials: M
authors.lastname: Lequin
authors.forename: Marry M
authors.initials: MM
authors.lastname: van den Heuvel-Eibrink
mesh_terms: D000971:Antineoplastic Combined Chemotherapy Protocols; D001706:Biopsy; D002454:Cell Differentiation; D017024:Chemotherapy, Adjuvant; D002675:Child, Preschool; D003937:Diagnosis, Differential; D018450:Disease Progression; D005260:Female; D006801:Humans; D007223:Infant; D052177:Kidney Diseases, Cystic / Q000188:drug therapy / Q000473:pathology / Q000601:surgery*; D007680:Kidney Neoplasms / Q000188:drug therapy / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D009392:Nephrectomy; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014463:Ultrasonography; D009396:Wilms Tumor / Q000188:drug therapy / Q000473:pathology / Q000601:surgery*