Wilms Tumor (Nephroblastoma)

Sharply demarcated large Wilms tumor with areas of necrosis and cyst formation on the bulging cut surface. About 10% of cases of Wilms tumor are associated with congenital malformation syndromes: WAGR Syndrome: consists of Wilms tumor, aniridia, genital anomalies, and mental retardation. The patients carry germline deletion of 11p13 locus which contains both WT1 and PAX6 genes. A frameshift or a nonsense mutation in the second WT1 allele (second hit) leads to the development of Wilms tumor in these patients. For Denys-Drash Syndrome and Beckwith-Wiedemann Syndrome, see the next two images. Image courtesy of Dr. Jean-Christophe Fournet, Paris, France; humpath.com; Used with permission