There are different types and subtypes of myeloma. These include light chain myeloma and non secretory myeloma.
There are also some other conditions related to myeloma. For example, MGUS, plasmacytoma and amyloidosis. Some of these conditions can develop into myeloma.
To understand about the different types of myeloma, it is helpful to know about plasma cells and immunoglobulins.
Immunoglobulins and your type of myeloma
Most people have a type of myeloma that causes the abnormal plasma cells to produce abnormal proteins. These proteins are called immunoglobulin (also called abnormal protein, paraprotein, monoclonal protein or monoclonal spike). As well as the whole immunoglobulin, often a small part called the free light chain (called Bence Jones protein in urine) is made in big amounts by the plasma cells.
Each immunoglobulin is made up of 2 long protein chains (called heavy chains) and 2 shorter protein chains (called light chains).
Immunoglobulins can be classified into one of 5 types depending on their heavy chains. These are A, G, M, D and E. Your type of myeloma is named after the abnormal immunoglobulin it is making.
Only one type of immunoglobulin (Ig) is overproduced when you have myeloma. The type of immunoglobulin this is varies from person to person. IgG is the most common. The next most common is IgA and light chain only. IgM, IgD and IgE are very rare.
Light chain myeloma sometimes called Bence Jones myeloma
About 15 out of 100 people with myeloma (15%) do not produce complete immunoglobulins. They only produce part of the immunoglobulin called the light chain.
There are 2 types of light chains - called kappa and lambda. The light chains can show up in the urine. Doctors call this the Bence Jones protein (BJP).
A blood test called a serum free light chain test can pick up small increases in the amount of free light chains in the blood. Doctors use this test to:
- measure the amount of each of the light chains in the blood
- to compare the amount of kappa light chains to the amount of lambda light chains, known as the ratio
Your doctor can use the test to diagnose and monitor your myeloma.
Non secretory myeloma
In around 3 out of every 100 people with myeloma (around 3%), the myeloma cells produce little or no abnormal immunoglobulin (paraprotein). This makes it harder to diagnose and monitor.
Doctors use bone marrow tests and scans (such as PET-CT) to diagnose and monitor non secretory myeloma.
Types of myeloma depending on gene changes
Myeloma develops when there is a change in the
Knowing the genetic subtype can help doctors know how your myeloma might progress. Doctors are doing research to understand more about these genetic subtypes. In the future, treatment options might vary, depending on your genetic subtype.
Other conditions related to myeloma
These are conditions that also affect plasma cells, and are related to myeloma:
- monoclonal gammopathy of undetermined significance (MGUS)
Monoclonal gammopathy of undetermined significance (MGUS)
MGUS is not cancer. But some people with it can go on and develop myeloma. If you have MGUS, your plasma cells make too many abnormal immunoglobulins. Doctors call these paraproteins or M protein. These show up in your blood test.
For most people, this doesn’t cause symptoms or affect your health. MGUS is often found by chance, in blood tests for a routine check up.
Doctors might diagnose MGUS if they find paraprotein in your blood. They look at the level of the paraprotein and do other tests to rule out other conditions like myeloma. They diagnose MGUS if:
- the level of abnormal paraprotein in your blood is less than 30 g/l
- the level of abnormal plasma cells in your bone marrow is less than 10%
- there is no evidence of certain other related conditions
- there are no related problems with organs or tissues
MGUS does not usually need treatment. Some people with MGUS go on to develop myeloma, so your specialist or GP will see you regularly for check ups. About 1 out of 100 people with MGUS (1%) develop myeloma each year.
A plasmacytoma is similar to myeloma. But the abnormal plasma cells are in one place and form a lump (tumour).
You might have:
- one area of plasmacytoma - a solitary plasmacytoma
- more than one plasmacytoma - multiple solitary plasmacytomas
Plasmacytoma can develop in the bone, or outside the bone in the soft tissue. A plasmacytoma outside the bone is called an extramedullary plasmacytoma.
More than 50 out of 100 (more than 50%) of people with bone plasmacytoma go on to develop myeloma later in life. Soft tissue (extramedullary) plasmacytoma can also develop into myeloma but is less common.
Doctors usually treat plasmacytoma with radiotherapy.
This is a rare conditon. The plasma cells make an abnormal protein called amyloid. The amyloid collects in body organs, such as the kidneys or heart, and gradually causes damage.
About 10 to 15 out of every 100 people with myeloma (10 to 15%) develop amyloidosis. But it doesn't always cause problems. However, it is rare for people with amyloidosis to develop myeloma.
Doctors usually treat amyloidosis with chemotherapy, and use the same drugs that you would have for myeloma.