Surgery for Wilms Tumors

Surgery is the main treatment for nearly all children with Wilms tumor. It should be done by a surgeon who specializes in operating on children and has experience in treating these cancers.

Removing the tumor

The main goal of surgery is to remove the entire Wilms tumor in one piece to keep the cancer cells from possibly spreading in the abdomen (belly). Surgeons who operate on these tumors are careful to limit the chance of this type of cancer spread whenever possible. If the surgeon finds (either with imaging tests done before surgery, or when starting the operation) that the entire tumor can’t be removed safely, other treatments may be used first. If these treatments shrink the tumor enough, surgery can then be done more safely.

Depending on the situation, different operations might be used.

Radical nephrectomy: This is the most common surgery for a Wilms tumor that’s only in one kidney, as it provides the best chance of making sure all of the tumor is removed. During this operation, the surgeon makes an incision (cut – usually down the middle of the abdomen) and removes the cancer along with the whole kidney, the fatty tissue around the kidney, the ureter (tube that carries urine from the kidney to the bladder), and the attached adrenal gland that sits on top of the kidney. Most children do very well with only one kidney.

Partial nephrectomy (nephron-sparing surgery): In the small number of children who have Wilms tumors in both kidneys, the surgeon will try to save some normal kidney tissue, if possible. The surgeon may remove the kidney containing the most tumor with a radical nephrectomy. In the other kidney the surgeon may do a partial nephrectomy, removing just the tumor and a margin of normal kidney around it. Another option might be partial nephrectomies on both kidneys.

Sometimes, both kidneys need to be removed completely. The child would then need dialysis several times a week. In this procedure, a machine does the job of the kidneys by filtering waste products out of the blood. Once the child is healthy enough, a kidney transplant may be an option if a donor kidney becomes available.

Assessing the extent of the disease (surgical exploration)

Another main goal of surgery (radical or partial nephrectomy) is to determine the extent of the cancer and whether or not it can all be removed. Lymph nodes near the kidney will be removed during surgery to look for cancer cells in them. Cancer often spreads to lymph nodes (bean-sized collections of immune cells). Lymph node removal is known as a regional lymphadenectomy.

The other kidney and nearby organs such as the liver may also be looked at closely, and any suspicious areas biopsied (samples taken to be checked for cancer under a microscope).

Knowing if a Wilms tumor has spread to the lymph nodes, the other kidney, or other nearby organs is important in determining its stage and further treatment options.

Placing a central venous access device (port)

Often, if the child is going to get chemotherapy, a surgeon will insert a small plastic tube called a catheter into a large blood vessel – usually under the collar bone. This tube may be called a venous access device, central venous catheter, or just a port. The tube might be put in during the surgery to remove the tumor, or as a separate operation (especially if chemo is going to be given before the surgery).

Possible risks and side effects of surgery

Surgery to remove a Wilms tumor is a serious operation, and surgeons are very careful to try to limit any problems either during or after surgery. Complications during surgery, such as bleeding, injuries to major blood vessels or other organs, or reactions to anesthesia, are rare, but they can happen.

Almost all children will have some pain for a while after the operation, although this can usually be helped with medicines if needed. Other problems after surgery are not common but can include internal bleeding, blood clots, infections, or problems with food moving through the intestines.

Most children do well when only one kidney is removed. But if there are tumors in both kidneys, another concern is the loss of kidney function. In these cases, doctors must balance between making sure the tumors are removed completely and removing only as much of the kidney(s) as is needed. Children who have all or parts of both kidneys removed may need dialysis, and may eventually need a kidney transplant.

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master's-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: March 6, 2015 Last Revised: February 16, 2016

American Cancer Society medical information is copyrighted material. For reprint requests, please see our Content Usage Policy.