Rai staging system for chronic lymphoid leukemia
The Rai staging system is one of the two staging systems currently adopted in assessment of chronic lymphocytic leukemia (CLL).
It comprises of stages 0 to IV and classifies chronic lymphocytic leukemia into low, intermediate and high-risk categories, which correspond with stages 0, I & II, and III & IV, respectively:
- Rai stage 0
- low risk
- lymphocytosis: a high lymphocyte count defined as more than 15,000 lymphocytes per cubic millimeter (> 15,000/mm)
- Rai stage I
- intermediate risk
- lymphocytosis and lymphadenopathy
- Rai stage II
- patients are also intermediate risk
- lymphocytosis plus an enlarged liver (hepatomegaly) or enlarged spleen (splenomegaly), with or without lymphadenopathy
- Rai stage III
- patients are high-risk
- lymphocytosis plus anemia with or without lymphadenopathy, hepatomegaly, or splenomegaly
- Rai stage IV
- high-risk
- lymphocytosis + thrombocytopenia (< 100-103 /dL)