[Successful induction and complete improvement of myelofibrosis and erythema nosodum with cladribine in a case of hairy cell leukemia].

The patient was a 45-year-old male who had been diagnosed with pancytopenia in 1998 at another hospital, where he continued treatment for idiopathic thrombocytopenic purpura (ITP) as an outpatient. After atypical lymphocytes were detected in his peripheral blood, he was admitted to our hospital for further examination in April 2002. Tests results revealed the additional existence of pancytopenia, splenomegaly, bone marrow fibrosis and erythema nodosum, in addition to the findings of surface marker. Tartrate resistant acid phosphatase (TRAP) staining and scanning electron microscopy of peripheral blood lymphocytes indicated hairy cell leukemia. After administration of cladribine (0.09 mg/kg) for 7 days, complete remission was obtained, with bone marrow fibrosis and erythema nodosum also being completely improved.