Blastic Mantle Cell Leukemia Maitaining Remission for 3 Years after the Treatment with Rituximab.

[Introduction] Blastic mantle cell leukemia is defined as CD5-positive, CD23-negative, cyclin D1-positive mature B-lymphoid tumor characterized by leukemic presentation, blastic blood and bone marrow features with aggressive clinical behavior. Its prognosis is usually dismal and overall survival was reported to be 3 months. We present the case of blastic mantle cell leukemia treated with rituximab, enjoying complete remission for 3 years.

[Case presentation] A 68 year-old man was admitted because of leukocytosis. His CBC revealed WBC 31.0 x 10E9/L with 64% of blast. Hemoglobin level was 5.3 g/dl, and 78% of medium-sized blasts that were positive for CD5, CD19, CD20, and HLA-DR. Chromosomal study revealed normal karyotype. He was treated with adriamycin, vincristine, cyclophosphamide, and predonisone as for acute lymphoblastic leukemia, and then, with another two cycles of intensive chemotherapy including hyper-CVAD without any significant response.

He was transferred to our hospital for further treatment. The blastic cells showed bcl1/IgH re-arrangement on FISH analysis and bone marrow biopsy revealed CD23-negative and cyclin D-positive that confirmed the diagnosis of mantle cell lymphoma/leukemia. CT scan of the body showed no significant lymphadenopathy.

He was treated with fludarabine and idarubicin without any effect and then was treated with rituximab 375 mg/m2. After the initiation of rituximab treatment, blasts disappeared from peripheral blood within 24 hours completely and after 4 times of rituximab once per every week, CBC returned to normal and bone marrow examination revealed complete remission. He was treated with another 2 injection of rituximab and then followed without any further treatment. He has been in complete-remission status for 3 years since then.

[Discussion] Blastic mantle cell leukemia is usually chemotherapy-resistant as our case is and its prognosis is dismal. Our case represent the possibility that even in those patients, one may enjoy prolonged complete remission after the simple treatment with rituximab. This is, of course, only a single case experience and it is necessary to proceed for further investigation.