Leukemic and meningeal relapse of CD5+ intravascular large B-cell lymphoma with down-modulation of CD20 after rituximab therapy.

Although CD20- relapses of B-cell lymphoma following rituximab therapy have increasingly been reported recently, coexistence of both the original and selected clones on relapse in a single patient have not been described. We experienced such a case with rare CD5+ intravascular lymphomatosis (IVL). A 46-year-old woman was admitted because of IVL complicated with cauda equina syndrome and pulmonary infarction. Complete remission was successfully achieved with multidrug chemotherapy in combination with rituximab. However, the disease recurred after 8 months with leukemic progression and meningeal involvement. The phenotype of the abnormal lymphocytes in the peripheral blood was fundamentally the same (CD20+CD5+CD10-CD19+CD23-sIglambda+) as that of the cells in the cerebrospinal fluid (CSF). However, CD20 expression was decreased remarkably compared with that in the CSF and that in the bone marrow before therapy. The targeting of CD20 molecules on the tumor cell surface by rituximab may have provided a selective pressure on lymphoma cells. The escape phenomenon of the lymphoma cells from rituximab was observed by simultaneously comparing the CD20 expression of cells in the peripheral blood and in a site of sanctuary from rituximab, the CSF.

[Successful attainment of the third chronic phase by autologous peripheral blood stem cell transplantation and imatinib in a patient with chronic myeloid leukemia].

Chronic myeloid leukemia in a 61-year-old man progressed into the accelerated phase 8 months after the initial evaluation (Ph chromosome [20/20], FISH 93.5%), although the major cytogenetic response (Ph chromosome [0/20], FISH 9.7%) had been achieved 6 months after the initiation of the treatment with interferon and hydroxyurea. The Peripheral blood stem cells (Ph chromosome [0/20], FISH 5.8%, PCR 2.7 x 10(2) copies/microgram RNA) were harvested simultaneously with the attempt to induce the second chronic phase using the mini-ICE (idarubicin, cytosine arabinoside and etoposide) therapy. However, 2 months later, the disease progressed into blast crisis with the additional chromosomal abnormalities, and did not respond to the re-induction therapy with idarubicin and cytosine arabinoside. Autologous stem cell transplantation was then performed using the preparatory regimen with busulfan and cyclophosphamide. The third chronic phase was successfully achieved, and has been well maintained with imatinib for more than 13 months (Ph chromosome [0/20], FISH 0.0%, PCR < 10(2) copies/microgram RNA). This may be a rare case in which normal hematopoietic stem cells could be enriched in the peripheral blood in the accelerated phase, and that cytogenetic remission was achieved using these cells in the blast crisis. Flexible use of peripheral blood stem cells and imatinib could be an additional strategy for the better treatment of chronic myeloid leukemia.

MALT lymphoma of the thymus with Sjögren's syndrome: biphasic changes in serological abnormalities over a 4-year period following thymectomy.

Thymic mucosa-associated lymphoid tissue (MALT) lymphoma shows distinct immunological characteristics, such as the expression of the IgA isotype, the frequent presence of immunoglobulin abnormalities, and a strong association with autoimmune disease, especially Sjögren's syndrome (SjS). We report a case of thymic MALT lymphoma, who exhibited biphasic changes in her clinical characteristics during the 4-year observation period after thymectomy. A 71-year-old woman was admitted because of suspected SjS. A diagnosis of primary thymic MALT lymphoma was made, and SjS was confirmed. Serological abnormalities such as polyclonal hypergammaglobulinemia, IgA M protein, and elevated levels of rheumatoid factor were noted. These abnormalities improved rapidly after the thymectomy, but did not completely disappear. Interestingly, the remaining abnormalities, which can be ascribed to the proliferation of B cells throughout the body under the influence of SjS, have been improving slowly but steadily during the 4-year observation period. It is suspected that the removal of the tumor by thymectomy has more or less normalized the immunological environment and alleviated the SjS disease activity.