Hairy Cell Leukemia

Hairy Cell Leukemia is an uncommon, indolent neoplastic lymphoid disorder characterized by an accumulation of neoplastic B cells in the bone marroe, spleen and peripheral blood. Is distinguished by the presence of "hairy" leukemic cells that have fine cytoplasmatic projections. This tumour occurs mainly in older males.

Symptoms, Signs and Diagnosis.

Splenomegaly - enlarged spleen - is a common and sometimes the only finding. Pancytopenia - diminished blood cells count - from bone marrow infiltration, reticulin fibrosis and splenic sequestation is typically present at diagnosis. Hepatomegaly - enlarged liver - and leucocytosis are less common and lymphadenopathy is rare. Osteolytic lesion can cause pain. The leukemic cells express B-cell-markers including CD19, CD20 and surface monoclonal immunoglobulin. The expression of CD11c and CD103, antigens not present on most other B-Cell tumours, help the diagnosis os Hairy Cell Leukemia. The diagnosis is made by identification of typical hairy cells in the peripheral blood or on bone marrow.

Treatment and Prognosis.

Asymptomatic patients without significant cytopenias or other complications can be monitored closely for progression or infection, but don't need immediate therapy. Patients with moderate cytopenias, symptomatic splenomegaly, bone involvement or autoimmune syndromes should undergo terapy. Unlike most other low g-rade lymphoid neoplasms, this tumor is extremely sensitive to chemotherapy, particularly purine nucleosides. First-line therapy is the purine analog 2-chlorodeoxyadenosine (2-CDA). 2-CDA has largely supplanted other therapies as IF-a or splenectomy. Complete durable responses are the rule, and the overall prognosis is exellent.