No generally accepted staging system is useful for both prognosis
For the purpose of treatment decisions, it is best to consider this disease in
2 broad categories: untreated hairy cell leukemia and progressive hairy cell
leukemia, either postsplenectomy or postsystemic therapy.
UNTREATED HAIRY CELL LEUKEMIA
Untreated hairy cell leukemia is characterized by splenomegaly, varying degrees
of leukopenia (occasionally leukocytosis) and/or pancytopenia, and bone marrow
infiltration by an atypical cell with prominent cytoplasmic projections (i.e., hairy
cells). The bone marrow is usually fibrotic and is not easily aspirated.
Bone marrow biopsies are, therefore, required for diagnosis and evaluation of the
degree of hairy cell infiltration.
PROGRESSIVE HAIRY CELL LEUKEMIA
Progressive hairy cell leukemia, postsplenectomy (or following any systemic
therapy) is characterized by progressive bone marrow replacement by hairy
cells with pancytopenia refractory to treatment. For patients with advanced
hairy cell leukemia treated with cladribine (2-chlorodeoxyadenosine, 2-CdA),
pentostatin, or interferon alfa, the survival rate appears to be >85% at 5 years after the initiation of any one of these therapies.[1,2]
- Frassoldati A, Lamparelli T, Federico M, et al.: Hairy cell leukemia: a clinical review based on 725 cases of the Italian Cooperative Group (ICGHCL). Italian Cooperative Group for Hairy Cell Leukemia. Leuk Lymphoma 13 (3-4): 307-16, 1994.
- Kurzrock R, Strom SS, Estey E, et al.: Second cancer risk in hairy cell leukemia: analysis of 350 patients. J Clin Oncol 15 (5): 1803-10, 1997.