Lytic Bone Lesion: An Unusual Presentation of Hairy Cell Leukemia.

Hairy cell leukemia (HCL) is a seldom encountered malignancy of lymphocytes with a low incidence in the United States. HCL generally follows an indolent course and not all patients require treatment. Most patients are asymptomatic at the time of diagnosis. Treatment is reserved for those with anemia, thrombocytopenia, neutropenia, recurrent infections, symptomatic splenomegaly, or lymphadenopathy impairing vital organ function. Purine analogs are the mainstay of treatment with a durable response. We report a case of a 49-year old Ukrainian male who presented with bone pain secondary to a lytic bone lesion who was diagnosed with HCL.