Classical hairy cell leukemia and its variant: a 17-year retrospective survey in Taiwan Chinese

Background: Classical hairy cell leukemia (HCL-C) and its variant (HCL-V) are rare chronic B-cell lymphoproliferative disorders. Only a few reports in Chinese patients are available.

Methods: We retrospectively reviewed 16 patients with HCL-C and HCL-V in Taiwan over a 17-year period.

Results: Eight were HCL-C and 8 were HCL-V. All HCL accounted for 0.7% of all adult leukemias. Compared to HCL-V, HCL-C was characterized by profound leukopenia, monocytopenia, thrombocytopenia and fewer circulating hairy cells. One HCL-C and 2 HCL-V patients had second malignancies. Seven HCL-C patients achieved hematological remission after splenectomy (n = 1) or 2-chlorodeoxyadenosine (n = 6). Of the 8 HCL-V patients, 6 received splenic irradiation. Only one achieved complete remission and another had partial remission; relapse or disease progression was noted 13.4 or 25.7 months later, respectively. Two of three HCL-V patients who underwent splenectomy had stable disease. All patients with HCL-C were alive while 3 with HCL-V expired. Compared to HCL-C, HCL-V had a significantly shorter leukemia-free survival.

Conclusion: A relatively higher proportion of HCL-V in all HCL comparing to Westerners is observed. Second malignancies are common. With an inferior outcome and dismal response to most treatment, enrollment in a clinical trial should be considered for HCL-V.