Neuroblastoma is a neuroendocrine tumor that usually develops in the adrenal glands, but can develop in any neuroectodermal tissue. One unique feature of disease is that a subset of children with metastatic disease located only in the liver, bone marrow, and skin, will demonstrate spontaneous regression. This Stage IV-S (S for special) does not require any form of chemotherapy.
Wilms tumor (also called nephroblastoma) is the most common renal malignancy in children. It develops from the embryologic metanephric blastema. The eponym was coined for German surgeon Max Wilms who first described the entity.
Since both tumors can be commonly found in the abdomen, they can easily be confused for each other radiographically. Here is a table that helps distinguish the two:
|Age||Less than 2 yrs||Peak at 3 yrs|
|Growth patten||Surrounds and engulfs vessels||Displaces vessels|
|Effect on kidney||Inferior displacement and rotation||Arises from kidney (claw sign)|
|Lung mets||No||Yes (20%)|
|Vascular invasion||No||Renal vein, IVC, right atrium|
Adapted from Pediatric Imaging: The Fundamentals, 1e by Lane Donnelly.
|Wilms Tumor with Claw Sign|
To summarize, Wilms tumor occurs in slightly older children, is centered in the kidney, and has vascular spread. Neuroblastoma is typically younger and more agressive, metastasizing by direct spread to liver and bone.