Myeloma shares some similar features and symptoms with other blood disorders, including:
- essential monoclonal gammopathy
- Waldenström macroglobulinemia
- heavy chain disease
- light chain deposition disease
- plasma cell leukemia
- POEMS syndrome
Essential Monoclonal Gammopathy
This common condition is often called MGUS after the other name it's commonly known by: monoclonal gammopathy of unknown significance. It usually affects older adults, especially those over age 60. Like myeloma, it's associated with M protein in the blood. However, increased levels of plasma cells in the bone marrow aren't evident and other features of myeloma such as anemia, bone damage and infections don't develop. Patients usually don't have symptoms unless the protein interacts with normal tissues, which it can occasionally do. In about 30 percent of patients, MGUS evolves into a progressive B-cell cancer like myeloma or lymphoma. Doctors monitor patients with blood tests once or twice a year to check for any changes to protein levels. Another name for the condition is benign monoclonal gammopathy.
Waldenström macroglobulinemia (WM) is a rare, slow-growing type of non-Hodgkin lymphoma that starts in the B lymphocytes and can affect the lymph nodes, liver and spleen. Like myeloma, it has elevated levels of M protein in the blood. Unlike myeloma, WM doesn't progress as rapidly nor does it lead to bone damage or fractures. For more about WM, download or order The Leukemia & Lymphoma Society's free fact sheet Waldenström Macroglobulinemia.
Amyloidosis can develop in patients with or without myeloma. If there's no myeloma, the condition is called primary amyloidosis. If myeloma is present, it's called secondary amyloidosis. Amyloid is an abnormal protein produced by abnormal cells. It can form deposits in tissue in the heart, digestive tract, kidney, nerves, skin and other areas, leading to organ failure. Many drugs that work against myeloma are also effective against amyloidosis.
Heavy Chain Disease
This rare disease is associated with myeloma because both diseases have abnormal B lymphocytes that produce abnormal monoclonal immunoglobulin (M protein). Normal immunoglobulin is made up of two large pieces (called heavy chains) and two smaller pieces (called light chains). In heavy chain disease, the immunoglobulin is incomplete; only the heavy chains are produced. Otherwise, the disease has clinical features different than those of myeloma's and it doesn't cause bone damage.
Light Chain Deposition Disease (LCDD)
A systemic disorder that involves the immune system, LCDD is 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 set off reactions leading to tissue or organ inflammation and damage. Early signs and symptoms of light chain deposition disease may include protein in the urine, high blood pressure, decreased kidney function and nephrotic syndrome (a kidney disorder that causes the body to excrete too much protein in the urine). LCDD can occur in patients who have myeloma as well as in individuals who have monoclonal gammopathy of undetermined significance (MGUS) or lymph node disorders.
Plasma Cell Leukemia (PCL)
A rare plasma cell disease that may be primary (de novo) or secondary, evolving from an existing diagnosis of myeloma. Most cases are primary; approximately 5 percent of cases are diagnosed in patients who have myeloma. In this disorder, patients have high numbers of plasma cells circulating in the blood. There are no curative treatments for PCL; options for therapy include supportive care and chemotherapy.
POEMS syndrome is a rare marrow disease. It gets it name from its five most common features: peripheral neuropathy (P), organ enlargement (O), endocrine gland dysfunction (E), monoclonal plasma cell tumors and monoclonal immunoglobulin (M) and skin changes (S). The neuropathy can be disabling, and the endocrine gland may not produce enough thyroid or sex hormone. Like myeloma, it damages the bones, but in a different way: the bone marrow appears denser instead of thinner.