title: Diagnostic utility of Wilms' tumour-1 protein (WT-1) immunostaining in paediatric renal tumours.
abstract: OBJECTIVE
  Renal tumours constitute about 7 per cent of all neoplasms in children. It is important to differentiate Wilms' tumour (commonest tumour) from non-Wilms' tumours. The aim of this study was to evaluate the immunoexpression and diagnostic role of Wilms' tumour-1 protein (WT1) in paediatric renal tumours.
  
  
  METHODS
  A total of 53 cases of renal tumours in children (below 18 yr) who underwent total nephrectomy were included in this retrospective study. WT1 immunostaining was done using mouse monoclonal WT1 antibody (clone: 6F-H2).
  
  
  RESULTS
  Of the 53 cases, 38 (72%) were of Wilms' tumour. Non-Wilms' group (15) included six cases of mesoblastic nephroma (MN), two each of clear cell sarcoma (CCSK), renal cell carcinoma (RCC) and peripheral neuroectodermal tumour (PNET) and one each of angiomyolipoma (AML), rhabdomyosarcoma (RMS) and malignant rhabdoid tumour (MRT). Proportion of WT1 positivity in Wilms' tumour was 100 per cent in contrast to 26.7 per cent in non-Wilms' tumours ( P<0.001). Epithelial and blastemal components of Wilms' tumour showed moderate (2+) nuclear and cytoplasmic staining in 80 (24/30) and 75 per cent (24/32) cases, respectively. MN, PNET, CCSK and AML were negative for WT1. RMS, RCC and MRT showed cytoplasmic staining, strongest in RMS. No significant association was seen between WT1 expression and NWTSG (National Wilms' Tumor Study Group) stage.
  
  
  CONCLUSIONS
  WT1 helps to differentiate Wilms' tumour from other paediatric renal tumours. It may help in differentiating the two subgroups of Wilms' tumour which have distinct molecular pathogenesis and biological behaviour, however, further prospective studies are required for validation of this hypothesis.
authors.affiliation: Department of Pathology, University College of Medical Sciences, Delhi, India.
authors.forename: Surbhi
authors.initials: S
authors.lastname: Goyal
authors.affiliation: Department of Pathology, University College of Medical Sciences, Delhi, India.
authors.forename: Kiran
authors.initials: K
authors.lastname: Mishra
authors.affiliation: Department of Pathology, University College of Medical Sciences, Delhi, India.
authors.forename: Urvee
authors.initials: U
authors.lastname: Sarkar
authors.affiliation: Department of Pathology, University College of Medical Sciences, Delhi, India.
authors.forename: Satendra
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Department of Pathology, University College of Medical Sciences, Delhi, India.
authors.forename: Anita
authors.initials: A
authors.lastname: Kumari
mesh_terms: D000293:Adolescent; D000911:Antibodies, Monoclonal / Q000235:genetics; D002292:Carcinoma, Renal Cell / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D002648:Child; D002675:Child, Preschool; D003937:Diagnosis, Differential; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007668:Kidney / Q000473:pathology / Q000601:surgery; D007680:Kidney Neoplasms / Q000145:classification / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D008297:Male; D009367:Neoplasm Staging; D009392:Nephrectomy; D025721:WT1 Proteins / Q000096:biosynthesis* / Q000235:genetics; D009396:Wilms Tumor / Q000145:classification / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology
chemical_list: D000911:Antibodies, Monoclonal; D025721:WT1 Proteins