Chromophobe renal cell carcinoma is a rare subtype of kidney cancer. It begins in the cells that line the small tubes in the kidney that filter waste from the blood to make urine.

A 2017 article notes that renal cell carcinoma accounts for more than 90% of cancers that affect the kidney. Chromophobe renal cell carcinoma is responsible for approximately 5% of kidney tumors.

Doctors look at the shape and size of cancer cells under a microscope to diagnose different subtypes of kidney cancer. They use this information to help tailor a treatment plan to an individual.

This article explains what chromophobe renal cell carcinoma is, how doctors diagnose it, and what to expect from treatment.

An imaging scan of chromophobe renal cell carcinoma.Share on Pinterest
SEBASTIAN KAULITZKI/SCIENCE PHOTO LIBRARY/Getty Images

Chromophobe renal cell carcinoma is a subtype of renal cell carcinoma. About 5% of people with renal cell carcinoma will have the chromophobe subtype.

The main difference between the subtypes is the shape and size of the cancerous cells. The most common type of renal cell carcinoma is clear cell renal cell carcinoma. Under a microscope, the cells are very pale or clear.

Chromophobe renal cell carcinoma is a type of non-clear cell renal cell carcinoma. Although the cells are also pale, they are much larger than other subtypes and have certain other characteristic features.

A 2021 comprehensive review points out that people with chromophobe renal cell cancer seldom have symptoms in the early stages. However, if symptoms occur, people may experience:

  • blood in the urine
  • flank pain
  • weight loss
  • abdominal lump
  • kidney dysfunction

If the cancer has spread to other areas of the body, a person may feel more widespread pain.

Doctors use stages 0–4 to classify tumors based on disease progression.

Staging takes into account the size of the tumor and whether it has spread into:

  • nearby tissues
  • distant lymph nodes
  • other organs around the body

A comprehensive 2021 review suggests that the chromophobe subtype is less aggressive for most people. This means that it grows quite slowly and is less likely to spread, or metastasize, than some other types.

If it does metastasize, chromophobe renal cell carcinoma usually spreads to the liver or lungs and, less often, to the bones.

According to the American Cancer Society (ACS), stage 1 describes a tumor that is no larger than 7 centimeters (cm) and is affecting one kidney.

A person with stage 2 cancer will have a tumor that measures more than 7 cm across. Although the cancer may have spread into the nearby tissue in the kidney or the veins supplying the kidney with blood, it has not spread to the lymph nodes or other organs in the body.

By stage 3, the tumors can be any size, and the cancer may have spread beyond the kidneys and the nearby lymph nodes. However, it has not yet spread beyond a network of fibrous, connective tissues that surrounds the kidneys, called the Gerota’s fascia.

By stage 4, the cancer:

  • has spread beyond Gerota’s fascia and may be developing into the adrenal gland, which sits on top of the kidney
  • may or may not have spread to nearby lymph nodes
  • has not spread to distant lymph nodes

Alternatively, the cancer:

  • can measure any size
  • may or may not have spread to the nearby lymph nodes
  • has spread to distant organs and distant lymph nodes

The Kidney Cancer Association (KCA) says that the average age at which people receive a kidney cancer diagnosis is 64 years. However, people with chromophobe renal cell carcinoma tend to be younger, with diagnoses being more common among those aged 40–50 years.

It also appears to be more prevalent among females than males.

Chromophobe renal cell carcinoma has associations with a rare genetic disorder called Birt-Hogg-Dubé syndrome, which causes benign, or noncancerous, growths in the skin. People with this syndrome have an increased risk of early onset renal cell cancer, including chromophobe renal cell carcinoma.

Risk factors

Certain factors increase the risk of getting chromophobe renal cell carcinoma.

According to the ACS, these include:

The ACS says that most kidney cancers are slow-growing.

For older adults and other people for whom treatment carries additional risks, doctors may suggest keeping an eye on any tumors to see whether they grow bigger than 4 cm.

This is called active surveillance. Doctors use imaging tests, such as MRI and CT scans, to monitor the tumor’s growth. They usually recommend scans every 3–6 months.

If the tumor grows larger than 4 cm, doctors will recommend treatment in the form of surgery or ablation.

Surgery for chromophobe renal cell carcinoma involves removing either the tumor itself or part or all of the kidney, depending on whereabouts in the kidney the cancer is growing. The removal of kidney tissue is called a nephrectomy.

During a partial nephrectomy, doctors remove the cancerous part of the kidney. In a radical nephrectomy, doctors remove the whole kidney and any surrounding tissues and lymph nodes.

The KCA says that this may be the only treatment that some people need.

If the cancer has spread to other parts of the body, doctors may suggest systemic — meaning whole body — drug treatments. The drugs travel through the blood, reaching the cancerous cells wherever they are in the body.

Doctors often recommend radiation therapy alongside systemic treatments, although research into new therapies is ongoing.

A person’s outlook depends on many factors, including the stage of cancer at the point of diagnosis and the person’s general health, well-being, and age.

The authors of a 2021 review note that people with localized chromophobe renal cell cancer may have a better outlook than people with some other renal cell carcinomas.

A 2019 article states that the diagnosis of the chromophobe subtype typically occurs when the disease is in the early stages. Due to this, the 5-year survival rate is 100%, and the 10-year survival rate is 90%.

Doctors use a variety of tests to diagnose kidney cancers. These include:

  • a physical exam to feel for lumps
  • urine samples
  • blood tests to check for anemia and any abnormalities
  • imaging tests, including CT scans, ultrasounds, and MRIs
  • kidney biopsy, in which doctors remove a small sample of kidney tissue and send it to a lab for analysis

Doctors may recommend additional tests if they suspect that the cancer has spread.

Although many people with chromophobe renal cell cancer do not experience any symptoms of kidney cancer, the ACS recommends that people contact a doctor if they have any of these symptoms:

  • blood in the urine
  • unexplained pain in the side or lower back
  • anemia
  • a lump, or mass, on the side or lower back
  • fatigue
  • unexplained weight loss
  • a persistent fever that is not the result of an infection

Chromophobe renal cell carcinoma is a rare subtype of renal cell carcinoma. It develops in the cells that line the small tubes in the kidneys that help filter out waste from the blood.

People may not experience symptoms. However, if symptoms do appear, a person may notice blood in their urine, flank pain, an abdominal lump, and weight loss.

It is typically a slow-growing cancer, and the outlook for those who receive a diagnosis is generally favorable.