Kidney Tumor

A kidney tumor is a mass or group of abnormal cells that form on your kidney. They may be benign (not cancerous) or malignant (cancerous).

Benign tumors don’t spread to other parts of your body. About 1 out of every 5 kidney tumors is benign. Many benign kidney tumors grow slowly. Some may not grow at all for a period of time.

Malignant tumors can be small or large. In general, the larger the tumor, the more likely it is to be cancer. Cancer can grow over time and may spread (metastasize) to other parts of your body.

Kidney cancer is one of the most common cancers in the U.S. Experts estimate over 80,000 people will receive a kidney cancer diagnosis in 2025.

Other names for kidney tumors include kidney neoplasms, renal tumors and renal masses. “Renal” is another word for kidney.

What are the first signs of a kidney tumor?

Many people don’t have any signs or symptoms. Kidney tumors often don’t cause pain or any other symptoms. A healthcare provider usually finds a kidney tumor while testing for other health conditions. If you have any signs or symptoms, they usually include:

• Blood in your pee (hematuria)
• Flank pain to the touch
• Lower back pain
• Loss of appetite
• Unexplained weight loss
• Fever
• Low red blood cell levels (anemia)

Causes

Experts don’t know the exact causes of kidney tumors. But you may increase your chances of developing them if you:

• Use tobacco products
• Have a body mass index (BMI) greater than 25 (have overweight/obesity)
• Have high blood pressure (hypertension)
• Have a biological family history of kidney tumors

Risk factors

Anyone can get a kidney tumor. But you’re more likely to get it if you’re:

• 65 or older
• Male
• Black, Hispanic, Native American, Alaskan Native or First Nation

Children are less likely to develop kidney tumors. If your child develops a kidney tumor, it’s most likely to be a Wilms tumor. Wilms tumors are the most common type of kidney tumor in children 15 and younger.

How do they spread?

Benign kidney tumors don’t spread to other parts of your body.

Malignant tumors can grow into nearby tissues, such as the fat or blood vessels around the kidney. They may then spread to other parts of your body through the bloodstream or lymphatic system.

How fast does a kidney tumor spread?

Kidney tumors don’t spread at a universal rate. Some only affect your kidney and don’t get much bigger. Some grow and spread slowly. Aggressive kidney tumors may grow and spread quickly.

Healthcare providers use cancer staging to describe how big a kidney tumor is and if it has spread. They use cancer grading to describe how cancer cells look and how fast they multiply. If their appearance changes, it’s more likely to be aggressive.

How doctors diagnose a kidney tumor

Healthcare providers usually discover a mass on your kidney during tests for other conditions. If you have symptoms, your healthcare provider will:

• Review your health history
• Ask if you have a biological family history of kidney tumors or cancer
• Conduct a complete physical exam

They may also recommend tests, like:

• Imaging tests, including a CT scan, MRI, ultrasound or bone scan
• Urinalysis to look for small amounts of blood in your pee that you can’t see with the naked eye
• Blood tests count the number of each kind of blood cell, look at the different electrolytes in your body and measure your creatinine levels to see if your kidneys are working as well as they should
• Renal mass biopsy to look for any cancer cells in the tumor

Is a kidney tumor curable?

With early diagnosis and proper treatment, kidney tumors may be curable.

Noncancerous kidney tumors usually aren’t life-threatening. Cancerous tumors are most treatable if a provider finds them before they grow beyond the kidney and spread.

How is it treated?

Kidney tumor treatment depends on the size of the tumor and whether it’s cancerous or noncancerous. Your treatment options may include:

• Active surveillance: For smaller kidney tumors, your provider may recommend regular screenings and imaging tests. They won’t offer treatment unless they see changes. You may get tests every three months, six months or once a year.
• Nephrectomy: Your provider may recommend removing part of your kidney (partial nephrectomy) or all of it (radical nephrectomy), depending on the size of your tumor.
• Ablation therapy: This treatment uses extreme heat (radiofrequency ablation) or cold (cryoablation) to destroy tumor cells.
• Radiation therapy: Your provider uses radiation to destroy tumor cells. Your provider may recommend it if you have only one kidney or can’t have surgery.
• Immunotherapy: This involves medications that help your immune system do a better job of recognizing and destroying tumor cells.
• Targeted drug therapy: Your provider may recommend targeted drug therapy if you can’t have surgery, or they may recommend it after surgery to prevent cancer from coming back. Drugs help prevent tumor cells from growing and spreading, and may help stop the growth of new blood vessels or limit certain proteins that help cancer grow.

When should I see my healthcare provider?

Schedule an appointment with your healthcare provider if you have kidney tumor symptoms. These include blood in your pee, pain in your flank or lower back, and unexplained weight loss. They can conduct tests to see whether you have a kidney tumor.

During your appointment, you may wish to ask questions like:

• Where is my kidney tumor?
• Is it cancerous or noncancerous?
• How big is it?
• Has it spread to other areas?
• What treatment options do you recommend?
• How well will my kidney work after treatment?
• Can you recommend a urologist or oncologist?

What can I expect if I have a kidney tumor?

Your prognosis and treatment plan depend on many different factors. These include:

• The size of your kidney tumor
• Whether it’s cancerous or noncancerous
• Whether it has spread to other areas
• Your age
• Your general health

Your healthcare provider will give you a better idea of what to expect.

Are they usually cancerous?

About 3 out of 4 kidney tumors are cancerous. Smaller tumors are less likely to be aggressive. You may not need any treatment if you have a smaller tumor. But it’s a good idea to get regular checkups and make sure it isn’t changing.

What is the survival rate of a kidney tumor?

It depends on what type of kidney tumor you have. Noncancerous tumors aren’t usually life-threatening. The overall five-year survival rate for cancerous kidney tumors is 78%. But your survival rate may be different depending on whether the cancer has spread:

• If the cancer is only in your kidneys, the survival rate is 93%.
• If the cancer has spread to nearby lymph nodes or other tissues, the survival rate is 75%.
• If the cancer has spread to distant parts of your body, the survival rate is 18%.

Your healthcare provider will give you a better idea of what to expect after testing.