Waldenström Macroglobulinemia (WM)
Lymphoma is the most common blood cancer. The two main forms of lymphoma are Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL). Lymphoma occurs when cells of the immune system called lymphocytes, a type of white blood cell, grow and multiply uncontrollably. Cancerous lymphocytes can travel to many parts of the body, including the lymph nodes, spleen, bone marrow, blood, or other organs, and form a mass called a tumor. The body has two main types of lymphocytes that can develop into lymphomas: B lymphocytes (B cells) and T lymphocytes (T cells).
Waldenström macroglobulinemia which is a subtype of lymphoplasmacytic lymphoma, is a rare, indolent (slow-growing) B-cell lymphoma that occurs in less than two percent of patients with NHL. There are about 2,800 new cases of Waldenströmmacroglobulinemia diagnosed each year in the United States. The disease usually affects older adults and is primarily found in the bone marrow, although lymph nodes and the spleen may be involved. Lymphoma cells in the bone marrow grow and block normal cells, making it difficult for the bone marrow to produce normal amounts of red and white blood cells. This can result in anemia (low levels of red blood cells), neutropenia (low levels of white blood cells called neutrophils), and thrombocytopenia (low levels of platelets).
Patients with Waldenström macroglobulinemia have a high level of a protein called immunoglobulin M (IgM) in their blood. High levels of IgM can cause hyperviscosity (thickening of the blood). Although some patients experience no symptoms, when present, symptoms may include bleeding (particularly of the nose and gums), headaches, dizziness, double vision, tiredness, night sweats, pain or numbness in the extremities, and increased size of the liver, spleen, and lymph nodes.
To diagnose Waldenström, macroglobulinemia, blood and urine tests are usually performed, as well as a bone marrow biopsy. During the biopsy, a needle is inserted into a bone (usually the pelvic bone), and a small sample of bone marrow is extracted for examination.