Nephrectomy specimen showing a large necrotic ruptured Wilms tumor in a 4 y/o female. The tumor ruptured one week post-chemotherapy. An adherent loop of small bowel can be seen on the lower right of the image. About 80% of the tumor was necrotic. The remainder was composed of a few nodules of blastema surrounded by abundant mesenchymal elements with focal rhabdomyomatous differentiation. Any tumor spillage during or before surgery would make this a Stage III tumor (National Wilms Tumor Study). Image copyright: pathorama.ch.