Multiple myeloma and chronic lymphocytic leukemia are both types of blood cancer that affect the white blood cells. However, important differences exist between these conditions. These differences relate to the symptoms, diagnosis, and treatment of the cancers, as well as the outlook for people living with them.

Multiple myeloma and chronic lymphocytic leukemia (CLL) are cancers of the white blood cells. In a person with CLL, the body produces excessive numbers of abnormal B cells. Multiple myeloma begins in a person’s plasma cells. These are a type of B cell that produces antibodies.

It is very unusual for someone to have multiple myeloma and chronic lymphocytic leukemia at the same time, but this can happen.

This article will compare the causes, symptoms, diagnoses, and treatment of these conditions, as well as the outlook for people living with them. It will also discuss whether multiple myeloma can turn into CLL and the possibility of having both conditions at once.

Both multiple myeloma and CLL result from a buildup of B cells, which develop in the stem cells in the bone marrow. B cells are an important part of the immune system.

Learn more about how white blood cells work here.

Multiple myeloma causes

As a 2021 review explains, multiple myeloma is a type of blood cancer that affects the production of plasma cells within the bone marrow. Scientists remain uncertain about what causes this condition.

Multiple myeloma involves genetic mutations, but what causes those mutations is unknown. There is nonetheless some evidence that risk factors for multiple myeloma include:

  • radiation exposure
  • exposure to insecticides or organic solvents
  • obesity
  • alcohol consumption

CLL causes

A different 2021 review notes that CLL, another type of blood cancer that begins in the bone marrow, has a genetic component. However, it also shares some of its risk factors with multiple myeloma. These risk factors include:

  • radiation exposure
  • tobacco smoking
  • exposure to benzene, although more research is necessary to confirm this


A person’s risk of developing CLL is five to seven times higher if they have a parent or sibling with the condition. For people with multiple myeloma, this risk is lower. They are four times as likely to develop the condition if they have a first degree relative who has it.

However, while multiple myeloma appears to run in families, most individuals with the disease have no family history of it.

Both multiple myeloma and CLL are slow growing, so the initial symptoms may not appear for a while.

The two conditions also have many symptoms in common.

Why are the symptoms so similar?

Multiple myeloma and CLL both begin in the bone marrow. They cause B cells to grow excessively, which disrupts the function of other, healthy blood cells.

Bones and low blood count

Multiple myeloma and CLL can both affect the bones. However, this is more common with multiple myeloma, which may cause symptoms such as:

  • painful bones
  • weak bones
  • fractures

Through their effects on the bone marrow, multiple myeloma and CLL can also lead to a low blood count, which may result in:

  • dizziness
  • weakness
  • shortness of breath
  • reduced resistance to infection
  • excessive bleeding

Calcium in the bloodstream

Additional symptoms of multiple myeloma and CLL may also be due to hypercalcemia, which is when too much calcium enters the bloodstream. This is more common in MM than CLL, in which there are few reported cases of hypercalcemia. Hypercalcemia can cause:

  • weakness
  • confusion
  • abdominal pain
  • dehydration
  • extreme thirst
  • kidney problems
  • constipation
  • muscle aches
  • cramping

Kidney damage

Finally, multiple myeloma and CLL can both cause severe kidney damage in their latter stages. This can lead to:

  • shortness of breath
  • weakness
  • itching
  • leg swelling
  • kidney failure
  • electrolyte disturbances

The diagnostic process for both multiple myeloma and CLL may involve blood tests and biopsies.

Multiple myeloma diagnosis

According to the American Cancer Society (ACS), doctors can confirm a diagnosis of multiple myeloma only if a person meets two criteria. Firstly, a biopsy must either reveal that plasma cells account for at least 10% of someone’s bone marrow or show that a plasma cell tumor is present. Secondly, at least one of the following must be true:

  • blood tests have revealed high blood calcium, anemia, or an unbalanced concentration of proteins called light chains
  • tests have identified poor kidney function
  • imaging tests have revealed holes in the bones
  • plasma cells make up more than 60% of the bone marrow

CLL diagnosis

The ACS also explains how doctors can diagnose CLL. As with multiple myeloma, a variety of tests can be helpful for diagnosis, including blood work and biopsies. Results that indicate the presence of CLL include:

  • blood contains too many lymphocytes, a type of white blood cell
  • presence of CLL cells in the bone marrow
  • evidence of CLL-causing genetic mutations, such as chromosomal changes
  • cancer cells in the lymph nodes

Many treatment options exist for both multiple myeloma and CLL. The specific details will vary from person to person depending on the severity of their condition and the ability of their body to handle the potentially aggressive cancer treatments.

Watchful waiting

Treatment may not be necessary until the person begins showing symptoms of CLL or multiple myeloma. This approach is called watchful waiting.

A person with either multiple myeloma or CLL may take years to start showing symptoms.

Stem cell transplant

A stem cell transplant can be a useful form of treatment for multiple myeloma and CLL. Doctors take stem cells from a person’s blood and reinject them after an aggressive form of treatment to help the body recover.

Stem cells can also recognize that the cancerous cells are foreign and attack them.

Learn more about stem cell transplants here.

Other common treatment options

Multiple myeloma and CLL share many similarities in terms of treatment. Possible treatment options for both conditions include:

With any condition, many factors can determine a person’s outlook. Some of these, such as an individual’s responsiveness to treatment, will vary greatly. Others, including the effects of a condition on someone’s mental health, can be hard to measure.

One important and useful outlook metric is the 5-year relative survival rate. This metric shows the percentage chance of a person with a particular condition being alive 5 years after receiving the diagnosis compared with someone without the condition.

The 5-year relative survival rate for multiple myeloma is 54%. For CLL, it is 87.2%. However, this can vary based on the extent and stage of the condition.

Scientists are making significant medical advances that are improving the outlooks for people with these conditions.

Learn about leukemia survival rates by age here.

A 2018 study found evidence that multiple myeloma and CLL share multiple genetic commonalities.

This overlap means that some of the genetic processes that cause multiple myeloma can lead to CLL and vice versa. However, there is no scientific evidence to suggest that either condition can turn into the other.

It is indeed possible for an individual to have multiple myeloma and CLL at the same time. However, scientists believe that this is extremely rare, with only about 0.26% of people with multiple myeloma also having CLL.

CLL and multiple myeloma are both forms of blood cancer. However, they affect the white blood cells in different ways.

Due to their similarities, CLL and multiple myeloma can cause some of the same symptoms. People may undergo similar diagnostic tests for each, and some of the treatment options are the same. However, key differences include the outlook for people with these conditions and the extent to which genetics plays a role in the likelihood of developing them.