Multiple myeloma is an uncommon cancer affecting plasma cells in the bone marrow. Tumors in the bones and other organs can cause the cells to grow out of control. A complication of this cancer is amyloidosis, and both conditions share some similarities.

Amyloidosis is a condition associated with multiple myeloma. In amyloidosis, the abnormal plasma cells create many light-chain proteins that can form amyloid deposits. These deposits can cause organ damage. Doctors regard this form of amyloidosis as a complication of multiple myeloma.

Keep reading to learn more about the link between multiple myeloma and amyloidosis, including how doctors might diagnose and treat these conditions.

The plasma cells of the bone marrow are an important part of the immune system. If they becomeTrusted Source cancerous and grow out of control, doctors call this multiple myeloma. These plasma cells make abnormal antibodies called M-protein or monoclonal paraprotein, which can damage organs.

The American Cancer Society estimates that around 35,780 peopleTrusted Source will receive a diagnosis of multiple myeloma in the United States in 2024.

Amyloidosis is a group of rare and serious conditions that also involve the plasma cells. Primary amyloidosis, or AL (light chain) amyloidosis, is the most common type. Other forms of amyloidosis are unrelated.

AL amyloidosis is closely related to multiple myeloma. It involves the buildup of abnormal light-chain proteins that form amyloid deposits.

These deposits can damage organs and tissues throughout the body and make it difficult for them to function properly. Without treatment, amyloidosis can lead to organ failure.

Differences

Multiple myeloma and amyloidosis share a common cause: the presence of malignant plasma cells in the bone marrow.

However, in multiple myeloma, the primary issue is an abnormal growthTrusted Source of plasma cells that accumulate in the bone marrow. This buildup of plasma cells can then cause anemia and bone damage.

Conversely, in amyloidosis, plasma cells do not accumulate. Instead, they create abnormal light chains, which lead to deposits. This can happen independently of any tumors being present. Doctors may consider amyloidosis a complication of multiple myeloma.

There is an overlap between the two conditions, and often, doctors diagnose people with both.

Below are some potential causes of multiple myeloma and amyloidosis.

Multiple myeloma

Doctors do not knowTrusted Source exactly what causes multiple myeloma. However, changes or mutations in a person’s genetic material can trigger plasma cells to become malignant.

Some mutations in DNA may activate oncogenes — genes that promote cell growth. Other mutations may turn off tumor suppressor genes, which are genes that can slow down cell growth or cause cell death when appropriate.

Myeloma cells may also have chromosomal abnormalities. Typically, DNA fits into 46 chromosomes. Cancer cells can either have additional chromosomes or parts; sometimes the whole chromosome is missing.

For many people with this condition, parts of chromosome number 17 are missing in the myeloma cells, which makes the myeloma more aggressive.

Amyloidosis

Sometimes, multiple myeloma may lead toTrusted Source amyloidosis.

Additionally, inflammatory diseases can causeTrusted Source secondary amyloidosis, and genetics can play a role in the development of hereditary amyloidosis.

Below are the potential symptoms of these two conditions.

Multiple myeloma

Some individuals with multiple myeloma have no symptomsTrusted Source, while others may experience the following:

Amyloidosis

People with amyloidosis may have some of the above symptoms, such as nerve damage. However, they can also have issues, including:

  • Heart problems: The heart can become larger and weaker, leading to fluid buildup in the lungs and shortness of breath.
  • Enlarged liver: A person may be able to feel the liver below the right ribs.
  • Enlarged tongue: If amyloid deposits build up in the tongue, it can increase in size, leading to problems swallowing and breathing during sleep.
  • Skin changes: People may bruise easily and bleed into the skin surrounding the eyes— known as raccoon eyes.
  • Carpal tunnel syndrome: People may notice numbness and weakness in their hands.

Doctors diagnose multiple myeloma and amyloidosis by considering a person’s symptoms and ordering various tests, such as:

  • complete blood count, which measures the level of different cells and platelets in the blood
  • blood chemistry test, which can include checking levels of:
    • creatinine to show kidney health
    • albumin, which may be low in someone with multiple myeloma
    • calcium, which may be high in someone with advanced myeloma
  • urine test to measure the presence or levels of certain proteins in urine
  • quantitative immunoglobulin tests to measure levels of antibodies in the blood
  • electrophoresis to show what types of monoclonal and other antibodies are present in the blood
  • serum-free light chains to measure the amount of light chains in the blood, which is particularly useful for diagnosing amyloidosis
  • biopsy, such as bone marrow biopsy and fine-needle aspiration biopsy
  • imaging, which can include:
  • echocardiogram to assess heart health, as amyloidosis often affects the heart’s structure

Multiple myeloma

A doctor may diagnoseTrusted Source multiple myeloma after confirming a person has a plasma cell tumor, at least 10% plasma cells in their bone marrow, and one of the following:

  • elevated blood calcium level
  • poor kidney function
  • anemia
  • holes in the bones from tumors
  • an increase in one type of light chain with a ratio greater than 100 in the blood
  • at least 60% of plasma cells in the bone marrow

Amyloidosis

An amyloidosis diagnosis usually requires the above tests, as well as other tests that look for the buildup of abnormal proteins in the body. These can include:

  • fat pad biopsy
  • a kidney biopsy
  • heart biopsy
  • special cardiac imaging

Doctors often treat individuals with multiple myeloma or primary amyloidosis with a combinationTrusted Source of two or three chemotherapy agents.

The choice of drugs depends on the person’s health and whether the doctor plans on performing a stem cell transplant.

In a stem cell transplant, an individual receives chemotherapy to kill abnormal bone marrow cells and then receives healthy blood-forming stem cells to replace them.

The doctor may also recommend treatment for bone disease, such as bisphosphonates, alongside chemotherapy. The doctor may recommend radiation therapy if someone continues to have bone problems.

The following supportive treatments can also be beneficial:

  • antibiotics
  • transfusions to treat low blood cell counts
  • intravenous immunoglobulins

People with multiple myeloma have a 5-year relative survival rateTrusted Source of approximately 57%. This means someone with the condition is 57% as likely to live at least 5 years as someone who does not.

This figure comes from people diagnosed with multiple myeloma from 2012 to 2018. Recent advances over the past several years have led to an improvement in this number.

However, a person’s outlook depends on their overall health, age, kidney function, the levels of certain substances in their blood, and the characteristics of the tumor.

If an individual has amyloidosis, their outlook depends on the typeTrusted Source of amyloidosis they have and how they respond to treatments. Left untreated, it can be fatal.

An individual’s outlook depends on organ involvement because if amyloidosis affects the heart, it can significantly decrease the likelihood of survival.

People can speak with a healthcare professional for more information about their individual outlook.

Multiple myeloma and amyloidosis stem from abnormalities in the plasma cells of the bone marrow. Multiple myeloma causes an overgrowth of abnormal cells, while amyloidosis results in the secretion of abnormal proteins that can build up and damage organs.

Doctors use a similar approach to diagnose both conditions, including blood analysis, imaging studies, and bone marrow biopsies. Treatment for the conditions typically involves chemotherapy and may also involve stem cell transplant.

People with multiple myeloma have a 5-year relative survival rate of approximately 57%. However, if someone has amyloidosis, their outlook depends on how much organ damage they have sustained.