Variable manifestation in natural killer cell leukaemia.

Natural killer (NK) cell leukaemias are a relatively rare group of haematological disorders, now entitled in the T/NK lymphoproliferative disorders in the new WHO classification. Recent studies have clarified their biological and clinical manifestation gradually. However, some cases with NK malignancies still remain difficult to diagnose and differentiate into their subtypes in the absence of a distinct diagnostic hallmark, especially at initial presentation. We describe herein five patients with NK leukaemias with respect to the clinical, cytological, immunological and cytogenetic characteristics, varied among each case. Cytologically, two aggressive NK cell leukaemia/lymphoma (ANKL/L) cases were a morphologically hypogranular variant form. Clinically, one with ANKL/L was presented as haemophagocytic syndrome without leukaemic infiltration. Systemic chemotherapy resulted in complete remission in one ANKL/L and two blastic NK cell leukaemia/lymphoma (BNKL/L) patients; however, a good long-term outcome was achieved in only one CD4-positive BNKL/L patient with allogenic bone marrow transplantation. Cytogenetic analysis revealed that recurrent chromosomal aberration was rare; however, two had aberrations at 10p11 and 11q13. From these findings, we conclude that comprehensive individual studies should be carried out in these patients to obtain a correct diagnosis and to design an optimal therapeutic approach.

Non-myeloablative haematopoietic stem cell transplantation for severe aplastic anaemia with various complications.

We report a 20-year-old-male with severe aplastic anaemia who was treated with nonmyeloablative haematopoietic stem cell transplantation (NSCT) from a sibling donor. As the patient presented with complications consisting of mental retardation, severe obesity, a bone fracture, and recurrent infections, we selected NSCT instead of a myeloablative regimen, to reduce regimen-related toxicity (RRT). Conditioning therapy consisting of busulfan, fludarabine, antithymocyte globulin and FK506 was used to obtain immune suppression. RRT was limited and he is now in complete remission 19 months after NSCT. On day 91, he developed chronic graft-vs.-host disease; it was resolved by the combination of FK506, corticosteroids, and mycophenolate mofetil. Our experience contributes to the growing interest in NSCT as a modality for treating not only malignant haematological disorders associated with complications, but also nonmalignant haematological diseases.