Binet Staging classifies CLL according to the number of lymphoid tissues that are involved (i.e., the spleen and the lymph nodes of the neck, groin, and underarms), as well as the presence of low red blood cell count (anemia) or low number of blood platelets (thrombocytopenia):

• Binet Stage A patients have fewer than three areas of enlarged lymphoid tissue. Enlarged lymph nodes of the neck, underarms, and groin, as well as the spleen, are each considered “one group,” whether unilateral (one-sided) or bilateral (on both sides).
• Binet Stage B patients have more than three areas of enlarged lymphoid tissue
• Binet Stage C patients have anemia plus thrombocytopenia (platelets <100 – 103 /dL).