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.
Hypervascular: similar to hyaline vascular features, but seen in iMCD rather than UCD. Includes regressed germinal centers, follicular dendritic cell prominence, hypervascularity in interfollicular regions, and prominent mantle zones with an "onion-skin" appearance. Mixed: presence of a combination of hyaline vascular/hypervascular and plasmacytic features in the same lymph node.UCD most commonly demonstrates hyaline vascular features, but plasmacytic features or a mix of features may also be seen. iMCD more commonly demonstrates plasmacytic features, but hypervascular features or a mix of features are also seen. All cases of HHV-8-associated MCD are thought to demonstrate plasmablastic features—similar to plasmacytic features, but with plasmablasts present. The clinical utility of subtyping Castleman disease by histologic features is uncertain, as histologic subtypes do not consistently predict disease severity or treatment response. Guidelines recommend against using histologic subtype to guide treatment decisions. Staining with latency-associated nuclear antigen (LANA-1), a marker for HHV-8 infection, should be measured in all forms of Castleman disease but is positive only in HHV-8-associated MCD.Diseases other than Castleman disease can present with similar histologic findings in lymph node tissue, including:
Infectious causes: Epstein-Barr virus, human immunodeficiency virus, tuberculosis
Autoimmune diseases: Systemic lupus erythematosus, rheumatoid arthritis
Lymphoproliferative disorders: lymphoma, autoimmune lymphoproliferative syndrome

History
Unicentric Castleman disease was first described in a case series by Benjamin Castleman in 1956. By 1984, a number of case reports had been published describing a multicentric variant of the disease and with some reports describing an association with Kaposis sarcoma. In 1995, the association between HHV-8 and Castleman disease was described in patients with HIV.