In chronic lymphocytic leukemia, which Rai stage and which Binet stage correspond to the presence of splenomegaly?

Splenomegaly in CLL Staging

In chronic lymphocytic leukemia, splenomegaly corresponds to Rai Stage II (intermediate-risk) and can appear in Binet Stage A or B depending on the number of involved lymphoid areas. 1

Rai Staging System

Rai Stage II specifically defines splenomegaly (with or without hepatomegaly) as an intermediate-risk category, regardless of lymphadenopathy presence. 1

• Rai Stage 0 (low-risk): Lymphocytosis only (>5 × 10⁹/L) 1
• Rai Stage I (intermediate-risk): Lymphocytosis + lymphadenopathy 1
• Rai Stage II (intermediate-risk): Lymphocytosis + hepatomegaly and/or splenomegaly with/without lymphadenopathy 1
• Rai Stage III (high-risk): Lymphocytosis + hemoglobin <110 g/L with/without lymphadenopathy/organomegaly 1
• Rai Stage IV (high-risk): Lymphocytosis + platelets <100 × 10⁹/L with/without lymphadenopathy/organomegaly 1

Binet Staging System

In the Binet system, splenomegaly counts as one of five lymphoid areas, and staging depends on total number of involved areas plus blood counts. 1

The five anatomical areas assessed are: 1

• Head and neck (including Waldeyer ring)
• Axillae (bilateral counts as one area)
• Groins (bilateral counts as one area)
• Palpable spleen
• Palpable liver

Binet Stage Assignment with Splenomegaly:

• Binet Stage A: Hemoglobin ≥100 g/L AND platelets ≥100 × 10⁹/L AND ≤2 involved areas (splenomegaly alone or with one other area) 1, 2

• Binet Stage B: Hemoglobin ≥100 g/L AND platelets ≥100 × 10⁹/L AND ≥3 involved areas (splenomegaly plus two or more other areas) 1, 2

• Binet Stage C: Hemoglobin <100 g/L and/or platelets <100 × 10⁹/L, regardless of splenomegaly or number of involved areas 1, 2

Critical Clinical Distinction

Isolated splenomegaly (without lymphadenopathy, anemia, or thrombocytopenia) represents a distinct favorable prognostic subgroup with median survival >10 years. 3, 4, 5

• This "pure splenic form" should be recognized as having an indolent course comparable to Rai Stage 0 patients 3, 4
• These patients can be managed with watch-and-wait strategy, with clinical examinations every 3-12 months 1, 2
• Treatment is only indicated if active disease develops (B-symptoms, cytopenias, symptomatic organomegaly, or lymphocyte doubling time <6 months with count >30 × 10⁹/L) 1

Practical Staging Assessment

Physical examination alone is sufficient for staging—imaging is not required. 1, 2

• Palpable spleen must be documented on physical examination (>1 cm below costal margin) 1
• Complete blood count with differential is the only laboratory requirement for staging 1, 2
• Bone marrow biopsy is not needed for initial staging 2