Renal Tumors in Children beyond the Age of 10 Years
S Popov, NJ Sebire, C Jones, K Pritchard-Jones, GM Vujanic. The Institute of Cancer Research, London, United Kingdom; Great Ormond Street Hospital/Institute of Child Health, London, United Kingdom; School of Medicine Cardiff University, Cardiff, United Kingdom
Background: Wilms tumor (WT) is the most common renal tumor in children, but, in addition, different epithelial, mesenchymal, neuroectodermal and hematopoietic neoplasms may also arise in the kidney during childhood. Several of these tumors show specific age distribution: in the first year of life mesoblastic nephroma and rhabdoid tumor are more common than in older children, whereas renal cell carcinoma (RCC), primitive neuroectodermal tumor (PNET) and anaplastic WT rarely occur in infants. The aim of this study is to demonstrate a spectrum of renal tumors in children aged 10 to 16 years.
Design: For this study we used data from 1492 cases from UKW3 (1991-2001) and SIOP (2002-2008) clinical trials. All cases were submitted for central pathology review and cases from the UKW3 trial were reclassified according to the current criteria.
Results: In total 69/1492 (4.6%) tumors in children aged 10 to 16 years were identified including 50 WTs (73.5% of all renal tumours in this group), 10 RCC (14.7%), three (4.3%) renal medullary carcinoma, two (3%) PNET; one (1.4%) clear cell sarcoma of kidney, one desmoplastic small round cell tumor, and one case where the diagnosis of a malignant tumor of uncertain origin was made. The frequency of WT with diffuse anaplasia in this age group was rather high – 7/69 (10%) including 9.4% in the SIOP and 14.9% in UKW3 trials. This contrasts with the frequency of WT with diffuse anaplasia in patients under 10 years of age - 5.5% and 4%. In the group of RCC, the following types were identified: RCC tXp 11.2 - 4 cases; papillary type II - 3 cases; papillary RCC type I - 1 case; clear cell RCC – 1, RCC unclassified - 1 case.
Conclusions: Our result showed that among renal tumours in children 10 - 16 years of age WT is still the most common malignancy although showing significantly higher proportion of diffuse anaplasia. Second most common type of tumors were different variants of RCC and their frequency is much higher that in younger patients.
Monday, March 22, 2010 1:00 PM
Poster Session II # 195, Monday Afternoon