According to the model, factors predicting reduced survival are:

Age > 65 years
Hemoglobin ≤ 11.5 g/dL
Platelet count ≤ 100×109/L
B2-microglobulin > 3 mg/L
Serum monoclonal protein concentration > 70 g/LThe risk categories are:

Low: ≤ 1 adverse variable except age
Intermediate: 2 adverse characteristics or age > 65 years
High: > 2 adverse characteristicsFive-year survival rates for these categories are 87%, 68% and 36%, respectively. The corresponding median survival rates are 12, 8, and 3.5 years.The International Prognostic Scoring System for Waldenströms Macroglobulinemia has been shown to be reliable. It is also applicable to patients on a rituximab-based treatment regimen. An additional predictive factor is elevated serum lactate dehydrogenase (LDH). Epidemiology
Of cancers involving the lymphocytes, 1% of cases are Waldenström macroglobulinemia.Waldenström macroglobulinemia is a rare disorder, with fewer than 1,500 cases occurring in the United States annually. The median age of onset is between 60 and 65 years, with some cases occurring in late teens. History
Waldenström macroglobulinemia was first described by Jan G. Waldenström (1906–1996) in 1944 in two patients with bleeding from the nose and mouth, anemia, decreased levels of fibrinogen in the blood (hypofibrinogenemia), swollen lymph nodes, neoplastic plasma cells in bone marrow, and increased viscosity of the blood due to increased levels of a class of heavy proteins called macroglobulins.For a time, Waldenström macroglobulinemia was considered to be related to multiple myeloma because of the presence of monoclonal gammopathy and infiltration of the bone marrow and other organs by plasmacytoid lymphocytes.
This is attributed to the IgM monoclonal protein increasing the viscosity of the blood by forming aggregates to each other, binding water through their carbohydrate component and by their interaction with blood cells. Diagnosis
A diagnosis of Waldenström macroglobulinemia depends on a significant monoclonal IgM spike evident in blood tests and malignant cells consistent with the disease in bone marrow biopsy samples. Blood tests show the level of IgM in the blood and the presence of proteins, or tumor markers, that are the key signs of Waldenström macroglobulinemia. A bone marrow biopsy provides a sample of bone marrow, usually from the lower back of  the pelvis bone. The sample is extracted through a needle and examined under a microscope. A pathologist identifies the particular lymphocytes that indicate Waldenström macroglobulinemia. Flow cytometry may be used to examine markers on the cell surface or inside the lymphocytes.Additional tests such as computed tomography (CT or CAT) scan may be used to evaluate the chest, abdomen, and pelvis, particularly swelling of the lymph nodes, liver, and spleen. A skeletal survey can help distinguish between Waldenström macroglobulinemia and multiple myeloma. Anemia occurs in about 80% of patients with Waldenström macroglobulinemia. A low white blood cell count, and low platelet count in the blood may be observed.