Hairy cell leukemia is a rare disease comprising about 2% of lymphoid neoplasms. In this review, the biology, diagnostic criteria, and current therapeutic options in HCL-V and HCL-JV are presented.We conducted a database; PubMed and Embase comprehensive search up to December 2017, we search a relevant trail to our concern topic (hairy cell leukemia). HCL-V is a distinct clinico-pathological entity. However, differentiating HCL-V from classical HCL and splenic marginal zone lymphoma (SMZL), which are both connected with noticeable splenomegaly and circulating neoplastic cells with 'hairy' projections remain a problem. Patients with HCL-V are usually older, splenomegaly is less typical and leucopenia with granulocytopenia and monocytopenia are generally not seen. Bone marrow is usually easily aspirable, hyper-cellular with mild myelofibrosis.