title: Clear cell sarcoma of the kidney in children: experience in a developing country.
abstract: BACKGROUND
  Clear cell sarcoma of the kidney (CCSK) is a rare tumour comprising 4% of primary renal tumours in children. It has a unique constellation of chromosomal and molecular features and should no longer be viewed as an unfavourable histological variant of Wilms tumour. Little is known of its clinical presentation and pathological profile in children living in a developing country.
  
  
  OBJECTIVE
  To describe the clinical and pathological features of CCSK in children in our practice and to identify factors contributing to poor patient outcomes.
  
  
  METHODS
  A retrospective review of patients with a confirmed diagnosis of CCSK who presented for treatment at a single institution between 1990 and 2008.
  
  
  RESULTS
  14 patients fulfilled the inception criteria. They represented 4% of 356 patients presenting with primary renal tumours during the review period. Clinical and radiological features were indistinguishable from Wilms tumour. Tumours were large (Mean mass 1.4 kg; median 0.9 kg) and metastases were common (42%). Lung and lymph node metastases were more common than skeletal disease. Co-morbidity, particularly hypertension (64%) was common. Initial diagnosis by needle biopsy was correct in only two of seven patients (29%) leading to inappropriate neoadjuvant chemotherapy. Overall survival is poor with 57% of patients alive and disease free from 1 to 7 years off treatment.
  
  
  CONCLUSIONS
  In a developing country, CCSK is rare and clinically and radiologically indistinguishable from Wilms tumour. Associated hypertension is common. Pretreatment diagnosis is difficult and sampling errors using needle biopsies may be unavoidable. Treatment results are poor and, given the propensity for late recurrence in CCSK, may not be sustained.
authors.affiliation: Department of Paediatric Surgery, Nelson R Mandela School of Medicine, University of KwaZulu-Natal, Congella, South Africa. hadley@ukzn.ac.za
authors.forename: G P
authors.initials: GP
authors.lastname: Hadley
authors.forename: M H
authors.initials: MH
authors.lastname: Sheik-Gafoor
mesh_terms: D001707:Biopsy, Needle; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000556:secondary; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015897:Comorbidity; D003906:Developing Countries / Q000706:statistics & numerical data*; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007223:Infant; D007680:Kidney Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000556:secondary; D008207:Lymphatic Metastasis; D008297:Male; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology*; D009367:Neoplasm Staging; D012189:Retrospective Studies; D018227:Sarcoma, Clear Cell / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology / Q000556:secondary; D013019:South Africa / Q000453:epidemiology; D016019:Survival Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods; D009396:Wilms Tumor / Q000000981:diagnostic imaging