Etiology

 • Clonal expansion of mature B-cells (CD5⁺, CD23⁺)
 • Common in elderly

Pathogenesis

 • Accumulation of dysfunctional lymphocytes → immunosuppression

Clinical features

 • Painless lymphadenopathy, splenomegaly
 • Fatigue, night sweats, weight loss
 • Recurrent infections, autoimmune hemolysis

Lab findings

 • Lymphocytosis with “smudge cells”
 • Hypogammaglobulinemia
 • Flow cytometry: CD19⁺, CD5⁺, CD23⁺

Treatment

 • Observation (early stage)
 • Ibrutinib, rituximab (advanced)