Clinics and pathology Disease NHL of the low to intermediate grade. Phenotype / cell stem origin B-cell lineage. Epidemiology 5% of NHL; sex ratio: 3M/1F; median age: 65 yrs. Clinics Advanced disease (Ann Harbor stage III-IV) with generalized lymphadenopathies in 90%, bone marrow involvement (70%), frequent splenomegaly (50%), hepatomegaly (30%), and gastro-intestinal involvement (20%), and lymphocytosis (30%); elevated LDH in 50%. Pathology Small cleaved cell B-lymphocytes with inconspicuous nucleoli and pale cytoplasm; with a pan B-cell, CD5+, CD10-, CD23(in contrast with CLL) phenotype; diffuse, nodular and blastoid types, the latter having large cells and higher mitotic count.