To identify the knowledge of rare lymphoproliferative disorder, the clinical and biological features of three kinds of lymphoproliferative disorders with cytoplasmic projections were compared. The clinical manifestations, ultrastructure and immunophenotype were analyzed. The results showed that hairy cell leukemia (HCL), splenic lymphoma with villous lymphocyte (SLVL) and hairy cell leukemia-variant (HCL-V) had some common characters including splenomegaly, peripheral blood and bone marrow infiltration by villous lymphocyte and B lymphocyte immunophenotype; but these three disorders had specific features respectively. It was concluded that overall analysis of clinical and laboratory features might be contributive to the differential diagnosis of these three disorders.