Renal medullary carcinoma (RMC) is a cancer that affects the kidneys. It is a rare and aggressive type of cancer that may spread to other parts of the body.

RMC typically affects people who also have sickle cell trait (SCT). Symptoms of RMC can include blood in the urine and pain in the area between the ribs and hips.

A doctor may recommend surgery, chemotherapy, or radiation therapy to treat RMC.

This article discusses RMC in more detail, including its symptoms and causes. It also explores the diagnosis and treatment of RMC and the potential outlook for a person living with the condition.

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RMC is a type of cancerous tumor that starts in the renal medulla, which is the internal part of a person’s kidneys. It is a rare form of kidney cancer that typically affects young adults and adolescents who have SCT.

If a person has SCT, it means they have inherited one sickle cell hemoglobin gene and one typical hemoglobin gene. People with SCT can be at greater risk of developing various conditions, particularly those that affect the kidneys.

According to the American Society of Hematology, around 8-10% of African Americans may have SCT. Hispanic Americans from Central and South America and people of southern European, Mediterranean, Middle Eastern, Indian, and Asian descent may also develop SCT.

RMC is typically an aggressive form of cancer, which means it may grow and spread to other areas of the body quickly. Doctors may use the terms metastasis or metastatic cancer to describe when cancer spreads from the originating site to other parts of the body.

The most common places a person with RMC may experience metastasis include the lymph nodes, liver, and lungs. Research suggests that up to 95% of people with a RMC diagnosis will experience metastasis. Additionally, RMC affects the right kidney in over 75% of people.

When symptoms present, they may include:

However, it is important to note that many conditions may cause similar symptoms, which can make it difficult to achieve an early diagnosis.

For example, RMC may also cause symptoms similar to those of metabolic disorders, such as fatigue and muscle weakness.

There is no definitive evidence to conclude the exact cause of RMC. However, most people who develop it also have SCT or sickle cell disease (SCD). When a person has SCD, their red blood cells are in the shape of a sickle and can become rigid and sticky.

Typically, people with SCT do not experience symptoms related to SCD. However, in rare instances, a person with sickle cell trait may experience complications of sickle cell disease.

Some research suggests that when people have SCT, their red blood cells change into a sickle shape only in specific parts of the body, such as the renal medulla.

The cells contain INI1 proteins, which typically stop cells from becoming cancerous. When a person has SCT, sticky red blood cells may block the supply of blood to the renal medulla. The lack of blood supply to the renal medulla may damage the INI1 proteins, which may in turn lead to RMC.

Some research also suggests that when a person has SCT, high intensity exercise may increase the risk of RMC. However, moderate exercise may reduce the risk of RMC.

Some other risk factors for RMC may include:

  • Younger age: RMC is more common in ages of 11–39.
  • Male sex: Males may be twice as likely to develop RMC than females.
  • African American ethnicity: African American individuals may be more likely to develop RMC.

According to a 2017 clinical review, a doctor may consider RMC if a person has SCT, is under the age of 50 years, and presents with symptoms such as blood in the urine, pain between the pelvis and hips, and weight loss.

To diagnose RMC, a doctor may use imaging tests, including an ultrasound, MRI, or CT scan.

During imaging testing, RMC typically presents as a tumor that measures approximately 7cm, more commonly in the right kidney.

RMC is an aggressive form of cancer. It is common for RMC to spread to other parts of the body.

The standard treatment for RMC is surgery to remove the affected kidney. A person may receive chemotherapy to shrink the tumor before surgery if it is very large. However, chemotherapy is not always effective when treating RMC.

Following surgery, a person may receive chemotherapy or radiation therapy if the cancer has spread to other parts of the body.

RMC is an aggressive form of cancer that grows quickly and can spread to other parts of the body in approximately 95% of people. According to a 2017 clinical review, the median life expectancy at diagnosis is about 4 months.

If a person receives an early diagnosis and treatment of RMC and does not have metastatic disease, life expectancy may increase.

However, a 2016 article suggests that even if people with RMC receive treatment, less than 15% will survive for longer than 24 months.

A person with RMC should note that individual outlooks vary, so some people may survive for longer than statistics suggest. A healthcare professional can provide further information on an individual basis.

RMC is a rare, aggressive form of kidney cancer that typically affects younger adults and adolescents. A person with SCT may be more at risk of developing RMC.

Symptoms of RMC may include blood in the urine, pain in the area between the ribs and hip, and unintentional weight loss.

The first treatment option for RMC is typically surgery to remove the affected kidney. Following surgery, a person may require chemotherapy or radiation therapy.

Metastasis is common in RMC, and life expectancy following diagnosis is low. However, individual outlooks may vary, and early diagnosis and treatment of RMC may increase life expectancy. A doctor can provide more information about treatment and outlook for RMC on an individual basis.