A 2 year old child is seen on a routine visit in the pediatric clinic. Abdominal examination demonstrates a palpable, non-tender mass on the left side of the abdomen. The mother had no idea the mass was present and the pediatrician did not note the presence of the mass at the child's 18-month's visit for immunisation. Physical examination is otherwise unremarkable. If a CT guided biopsy of the mass were performed, which of the following histological patterns would be most suggestive of the likely diagnosis?

Adequate sampling of most Wilms tumors will detect the three distinct growth patterns that are most characteristic of this tumor: less cellular tumor areas containing spindle cells; densely cellular (blastemal) areas with closely packed small cells with scanty cytoplasm and darkly blue nuclei; and areas with production of more mature-appearing epithelium that may form occasional tubules. The tissues present are similar to those present in the developing kidney, and may also include primitive glomeruli. Wilms tumors may additionally contain heterologous elements, such as skeletal muscle, smooth muscle, squamous or mucinous epithelium, adipose tissue, cailage, bone, or neural tissue. First choice suggests renal cell carcinoma,second choice suggests transitional cell carcinoma & third choice suggests neuroblastoma.