Our data suggest improved clinical outcomes for patients with IVLBCL in the rituximab era. Future prospective studies of rituximab-containing chemotherapies are warranted.

Intravascular large B-cell lymphoma (IVLBCL) is a rare disease entity with a high incidence of central nervous system (CNS) involvement at diagnosis. To evaluate CNS involvement, particularly recurrence including progression on therapy and relapse of IVLBCL, we retrospectively analyzed 109 patients with IVLBCL receiving chemotherapies with or without rituximab. In 82 patients (75%) without CNS involvement at initial diagnosis, risk of CNS recurrence at 3 years was 25% with a median follow-up in survivors of 39 months (range, 2-158 months). In 27 patients (25%) with CNS involvement at initial diagnosis, risk of CNS recurrence at 1 year was 25% with a median follow-up in survivors of 18 months (range, 10-77 months). Duration from diagnosis to CNS recurrence tended to be short in patients with CNS involvement at diagnosis. No significant difference in risk of CNS recurrence was found between patients receiving chemotherapies with or without rituximab. On multivariate analysis skin involvement at initial diagnosis was identified as a predictive factor for CNS recurrence in patients without CNS involvement at diagnosis (hazard ratio, 5.27; 95% confidence interval, 1.59-17.4; P = 0.007). Survival rate after CNS recurrence at 2 years was 12% in patients without CNS involvement at diagnosis. Central nervous system recurrence is a serious complication in IV-LBCL patients and optimal strategies for CNS involvement should be established to obtain further improvements to clinical outcomes in the rituximab era. (Cancer Sci 2010; 101: 1480-1486 C entral nervous system (CNS) involvement, particularly recurrence including progression during therapy or relapse after completion of chemotherapy, represents a serious and usually fatal complication of aggressive lymphoma.(1-5) Risk of CNS recurrence differs according to the histological type of lymphoma, occurring in 30-50% of cases involving Burkitt lymphoma (BL) and acute lymphoblastic leukemia ⁄ lymphoma (ALL ⁄ LBL), (6) and in around 5% of cases with aggressive nonHodgkin lymphoma (excluding BL and LBL) without CNS prophylaxis.(7) In BL and LBL, prophylaxis and early diagnosis of CNS involvement have led to major decreases in the risk of CNS relapse. (8,9) Adopting an initial treatment strategy including CNS prophylaxis is thus important, given the risk of CNS relapse.In previous reports, risk of CNS relapse in diffuse large B-cell lymphoma (DLBCL) has been approximately 5% and various CNS risk factors have been described, including advanced stage, increased international prognostic index (IPI), elevated serum lactate dehydrogenase (LDH), >1 extranodal site, and retroperitoneal disease. (3,4,10) Intravascular large B-cell lymphoma (IVLBCL) has recently been classified as a distinct rare disease entity according to the current World Health Organization (WHO) classification. (11) Intravascular large B-cell lymphoma is a rapidly progressive and disseminated, often fatal, aggressive lymphoma, characterized by selective growth of lymphoma cells only in the lumina of small vessels in ...

SummaryTo clarify the regulatory mechanism of thrombopoietin (TPO, c-Mpl ligand) in chronic thrombocytopenic conditions, we determined TPO levels in the sera of patients with aplastic anaemia (AA; n = 26) and idiopathic thrombocytopenic purpura (ITP; n = 32) by an enzyme-linked immunosorbent assay. Despite a similarity in platelet counts, serum TPO levels in the AA group were markedly higher than those in the ITP group: 20.41 ± 9.71 f mol/ml (mean ± SD) and 1.66 ± 0.55 f mol/ml, respectively, both of which were significantly elevated compared to normal subjects (n = 41; 1.22 ± 0.37). In both groups, serum TPO level showed an inverse correlation with the platelet count. We determined the megakaryocyte volume using bone marrow clot section and found that it was markedly small in the AA group; while in the ITP group it was augmented with a correlation to serum TPO level. Our findings suggest that TPO levels may be regulated not only by platelets but also megakaryocytes in AA and ITP.