Background: Hairy cell leukemia (HCL) is a rare B-cell neoplasm that comprise approximately 2% of all lymphoid leukemias. Over the past 20 years splenectomy was the only effective therapy but with the advent of purine analogues such as cladribine, splenectomy has been limited to certain situations. After cladribine therapy most patients achieve complete and durable remission. The aim of this study was to compare effectiveness of splenectomy and cladribine in Iranian patients with HCL and also to evaluate the clinical and laboratory features of patients at diagnosis.
Methods: 50 patients with the diagnosis of HCL enrolled to our study. The male to female ratio was 3:1, and the median age at diagnosis was 50 years. After diagnosis  20(40%) and 12(24%) of patients had splenectomy and cladribine therapy respectively. The reminder of patients were treated with both splenectomy and cladribine.
Results: The most common clinical findings were splenomegaly (98%) and fatigue (80%) respectively. Leucopenia and anemia was present in 96% and 80% patients in order. 88.6% and 55.5% of patients achieved complete remission after cladribine therapy and splenectomy respectively. After cladribine therapy and splenectomy relapse occurred in 10% and 74% of the patients.
Conclusions: Our finding are comparable with previous studies and show that Cladribine induces complete and durable remission in most hairy cell leukemia patients and should be considered as first line therapy. Splenectomy should be performed in certain cases such as spleen rupture.