To identify the knowledge of rare lymphoproliferative disorder, the clinical and biologicalfeatures of three kinds of lymphoproliferative disorders with cytoplasmic projections were com-pared. The clinical manifestations, ultrastructure and immunophenotype were analyzed. The resultsshowed that hairy cell leukemia (HCL), splenic lymphoma with villous lymphocyte (SLVL) andhairy cell leukemia-variant (HCL-V) had some common characters including splenomegaly, periph-eral 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 ofclinical and laboratory features might be contributive to the differential diagnosis of these three dis-orders.