Successful treatment of small cell variant anaplastic large cell lymphoma with allogeneic peripheral blood stem cell transplantation, and review of the literature.

The small cell variant of anaplastic large cell lymphoma (ALCL) presents in a nearly identical manner to the more common ALK(+) primary ALCL, with the exception that it is more frequently associated with leukemic involvement, and the prognosis has been reported to be poor. We report a 40-year-old Japanese male who was diagnosed with small cell variant ALCL with peripheral blood involvement stage IVB, age-adjusted international prognostic index 3. Conventional cytogenetics of the bone marrow aspirate specimen showed abnormal metaphases with the following karyotype: 47, XY, +X, t(2;5)(p23;q35). The patient was treated with acute lymphoblastic leukemia-oriented intensive chemotherapy. He underwent allogeneic peripheral blood stem cell transplantation from his HLA-DR1 locus mismatch sister. Prior to transplant, the patient had residual lymphadenopathy considered to be in partial remission. As of August 2012, the patient has achieved 18 months of continuous complete remission (CCR), with a Karnofsky score of 100 %. We have identified a total of seven cases of small cell variant ALCL treated with allogeneic hematopoietic stem cell transplantation (HSCT) in the literature. Of these, no relapse was reported, and four patients were CCR more than 1 year. Allogeneic HSCT appears to represent a promising treatment option for small cell variant ALCL.