Related Diseases

Myeloma shares some similar features and symptoms with other blood disorders, including:

 
Monoclonal Gammopathy of Undetermined Significance (MGUS)

This condition, also called “benign monoclonal gammopathy,” is associated with monoclonal protein in the blood. It is present in 5 percent of the general population older than 50 years. Patients with MGUS do not usually experience any signs and/or symptoms of the condition and it does not affect their wellbeing. Consequently, over 50 percent of people who are diagnosed with MGUS have had the condition for many years prior to the diagnosis. Usually, MGUS is found as an incidental finding of routine laboratory tests. Almost all myeloma patients have MGUS before the condition progresses to myeloma, but only 20 percent of people diagnosed with MGUS eventually develop myeloma. Its associated risk of progression to myeloma is approximately 1 percent per year. Patients with MGUS are usually monitored with blood tests once or twice a year to determine if there is any change in the level of monoclonal protein.

For more information, view the free LLS fact sheet, Monoclonal Gammopathy of Undetermined Significance (MGUS) Information Sheet.

 
Monoclonal Gammopathy of Renal Significance (MGRS)

This condition occurs when a patient has features of asymptomatic myeloma, but nonetheless requires treatment due to the impact of the monoclonal proteins on kidney function. Both a bone marrow and a kidney biopsy are usually required to make the diagnosis. Typically, treatment for patients with this condition is similar to the treatment for patients with symptomatic myeloma.

Waldenström Macroglobulinemia (WM)

This disease has some features in common with myeloma. It is a malignancy of B lymphocytes that produce a monoclonal immunoglobulin that can be measured in the blood. The malignant B lymphocytes replace the normal marrow cells and may cause anemia and other blood cell deficiencies by preventing the normal marrow cells from making blood cells efficiently. The monoclonal (M) immunoglobulin produced by the malignant B lymphocyte is a very large type of immunoglobulin M (IgM), referred to as a “macroglobulin” (large globulin).

For more information, view the free LLS fact sheet, Waldenström Macroglobulinemia Facts.

AL Amyloidosis

AL amyloidosis (amyloid light chain or primary amyloidosis) is an uncommon disease process associated with the accumulation of “amyloid” in tissues, such as the heart, the gastrointestinal tract, the nerves or the skin. Although there are several types of amyloid, one type is associated with a condition known as “amyloid light-chain (AL) amyloidosis,” which is caused by the deposit of damaged immunoglobulin light chains. In some patients with myeloma, the light chains made by plasma cells can result in the formation and deposition (buildup) of amyloid. This type of amyloidosis can occur either with or without overt myeloma and is called “primary amyloidosis.” In myeloma patients who have primary amyloidosis, involvement of the heart, intestines or nerves can produce dysfunction in those organs, significantly complicating management of the disease.

In patients who have AL amyloidosis without myeloma, the number of plasma cells in the marrow may not be increased and the bones may not be affected. In these cases, the malignant B lymphocytes producing the light chains that build up in the tissues and form the amyloid are too few to be detected by a bone marrow biopsy. Diagnosis of amyloidosis relies on some of the same tests used to diagnose myeloma; however, occasionally it is necessary to perform biopsies of other sites, such as the abdominal fat pad, gums, colon, heart or kidneys. Staging is determined based on the results of blood tests that indicate heart function, including tests to measure N-terminal pro-brain natriuretic peptide (NT-proBNP) and either the troponin T or troponin I level. Many of the drugs that work against myeloma are also effective against amyloidosis, including corticosteroids, melphalan, bortezomib (Velcade®) and daratumumab (Darzalex®), while lenalidomide (Revlimid®) should be used with caution. The FDA granted accelerated approval to daratumumab plus hyaluronidase (Darzalex Faspro®) in combination with bortezomib, cyclophosphamide and dexamethasone for newly diagnosed light chain (AL) amyloidosis. In patients who are good candidates, autologous stem cell transplantation is the treatment of choice.

For more information, view the free LLS fact sheet, Amyloidosis Facts.

For information about the drugs listed on this page, visit Drug Listings.

Heavy Chain Disease

These are a family of rare, systemic syndromes involving B lymphocytes. They are called heavy chain diseases because the protein made by the malignant lymphocytes is an incomplete immunoglobulin (the heavy chain of the immunoglobulin). A heavy chain disease is similar to myeloma in that it is a malignancy of B lymphocytes that secrete a characteristic immunoglobulin, but its clinical features are quite different. For example, there is no bone disease. Treatment generally involves chemotherapy, corticosteroids and, in some cases, radiation therapy.

Light Chain Deposition Disease (LCDD)

This is a systemic disorder that involves the immune system, caused by an excess buildup of immunoglobulin light chains in the tissues and organs. Light chains are an important part of the body’s immune system. However, if they become trapped in the tissues of the kidneys, lungs, skin, joints or blood vessels, the light chains can trigger reactions that lead to tissue or organ inflammation and damage. Early signs and symptoms of LCDD may include protein in the urine, high blood pressure, decreased kidney function and nephrotic syndrome (a kidney disorder that causes the body to eliminate too much protein in the urine). Approximately 50 to 60 percent of patients with LCDD have myeloma, and about 17 percent have monoclonal gammopathy of undetermined significance (MGUS).

Plasma Cell Leukemia (PCL)

This is rare plasma cell disease that may be primary (without known cause) or secondary (evolving from an existing diagnosis of myeloma). Most cases are primary; only about 5 percent of cases are diagnosed in patients who have myeloma. In this disorder, patients have a high level of plasma cells (greater than 20 percent) circulating in the blood, often creating plasmacytomas throughout the body. This disease is treated like myeloma. However, patients frequently require more aggressive therapy because PCL is more aggressive than myeloma.

POEMS Syndrome

POEMS syndrome is an uncommon marrow disorder related to myeloma. It gets its name from its five most common features:

  • Peripheral neuropathy
  • Organ enlargement
  • Endocrine gland dysfunction
  • Monoclonal plasma cell tumors and monoclonal immunoglobulin
  • Skin changes

Peripheral neuropathy is often the most disabling feature of the syndrome and can include progressive weakness of the arms or legs. Liver or spleen enlargement is less common. The bone alterations related to the accumulation of plasma cells in the marrow are different from bone alterations in classic myeloma (the marrow looks denser than normal, rather than less dense). Thyroid or sex hormone deficiencies caused by endocrine gland dysfunction may require hormone replacement therapy. Other features not included in the POEMS acronym are high red blood cell or platelet counts, extravascular volume overload (swelling) and lung disease. Patients can benefit from radiation or chemotherapy treatment and, in some cases, from autologous stem cell transplantation.

 

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