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Surgery for Wilms Tumors

Surgery is the main treatment for nearly all children with Wilms tumors. It's important that it is 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, if possible. This is to keep the cancer cells from 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

A radical nephrectomy removes the entire kidney and some nearby structures. 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 belly, and removes the cancer along with the whole kidney, the adrenal gland that sits on top of the kidney, the surrounding fatty tissue, and the ureter (tube that carries urine from the kidney to the bladder). Most children do very well with only one kidney.

Partial nephrectomy (nephron-sparing surgery)

A partial nephrectomy removes only part of the kidney(s). For the small number of children who have Wilms tumors in both kidneys, this surgery might be done to try to save some normal kidney tissue. The surgeon may do a radical nephrectomy to remove the kidney containing the most tumor, and then a partial nephrectomy on the other kidney, removing just the tumor and a margin of normal kidney around it. Another option might be to do 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, and if a donor kidney becomes available, a kidney transplant may be an option.

Assessing the extent of the disease (surgical exploration)

When either radical or partial nephrectomy is done, another main goal of surgery 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 catheter (port)

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

One end of the catheter stays outside of the body or just under the skin, and can be used to give chemo or take blood samples without the need for more needle sticks into veins. The catheter can stay in place for months.

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.

More information about Surgery

For more general information about  surgery as a treatment for cancer, see Cancer Surgery.

To learn about some of the side effects listed here and how to manage them, see Managing Cancer-related Side Effects.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Chintagumpala M, Muscal JA. Treatment and prognosis of Wilms tumor. UpToDate. Accessed at on September 4, 2018.

Fernandez CV, Geller JI, Ehrlich PF, et al. Chapter 29: Renal Tumors. In: Pizzo PA, Poplack DG, eds. Principles and Practice of Pediatric Oncology. 7th ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2016.

National Cancer Institute. Wilms Tumor and Other Childhood Kidney Tumors Treatment (PDQ®). 2018. Accessed at on September 4, 2018.

Last Revised: October 17, 2018

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