Bilateral intrarenal pelvis Wilms' tumor with fibroepithelial polyp

Botryoid Wilms Tumor with Left-Sided Inferior Vena Cava: A Case Report

“…Several reports have suggested that these tumors are resistant to therapy. Others suggested the prognosis for these patients with complete resection remains excellent [1, 3‒5]. Tumor invasion through the wall of the ureter is seldom seen in histologic examination.…”

Bilateral botryoid nephroblastoma: a rare cause of renal failure

“…In a review of ten reports, Honda et al 2 described four cases of exclusively intrapelvic tumour, without an intraparenchymal component. This phenomenon is rare; to date, 26 individual cases of botryoid nephroblastoma have been the subject of case reports,3 while the National Wilms’ Tumour Study Group (NWTSG)4 have produced a review of 45 children (enrolled in NWTS 3,4 and 5) who were identified as having ureteral tumour extension. In the NWTSG series, the overall incidence of ureteral extension in NWTS-5 was 2%.…”

“…In the NWTSG series, the overall incidence of ureteral extension in NWTS-5 was 2%. Bilateral botryoid nephroblastomas are extremely rare; only two cases have been reported previously 3 5. In the first reported case,3 the presenting complaint was haematuria rather than renal failure, and bilateral fibroepithelial polyps (FEPs) were reported in association with the Wilms tumours.…”

“…Bilateral botryoid nephroblastomas are extremely rare; only two cases have been reported previously 3 5. In the first reported case,3 the presenting complaint was haematuria rather than renal failure, and bilateral fibroepithelial polyps (FEPs) were reported in association with the Wilms tumours. However, since the FEPs are reported to contain ‘primitive tubular and glomerular structures’ and ‘nephroblastomatoid tissues’ and they were resected after chemotherapy had commenced, it appears likely that this tissue represented nephroblastoma showing chemotherapy-effect.…”