title: Leukemic and meningeal relapse of CD5+ intravascular large B-cell lymphoma with down-modulation of CD20 after rituximab therapy.
abstract: 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.
authors.affiliation: Division of Hematology and Immunology, Department of Internal Medicine, Ohtsu Red Cross Hospital, Shiga, Japan. tatsohno@otsu.jrc.or.jp
authors.forename: Tatsuharu
authors.initials: T
authors.lastname: Ohno
authors.forename: Takashi
authors.initials: T
authors.lastname: Sakamoto
authors.forename: Chisaki
authors.initials: C
authors.lastname: Mizumoto
authors.forename: Takashi
authors.initials: T
authors.lastname: Miyoshi
authors.forename: Maki
authors.initials: M
authors.lastname: Ueda
authors.forename: Tomoharu
authors.initials: T
authors.lastname: Takeoka
authors.forename: Kouhei
authors.initials: K
authors.lastname: Yamashita
authors.forename: Terutoshi
authors.initials: T
authors.lastname: Hishita
authors.forename: Shigefusa
authors.initials: S
authors.lastname: Hada
mesh_terms: D000911:Antibodies, Monoclonal / Q000008:administration & dosage; D058846:Antibodies, Monoclonal, Murine-Derived; D018951:Antigens, CD20 / Q000134:cerebrospinal fluid; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000008:administration & dosage*; D018956:CD5 Antigens / Q000134:cerebrospinal fluid; D005260:Female; D015973:Gene Expression Regulation, Leukemic / Q000187:drug effects; D006801:Humans; D008214:Lymphocytes / Q000378:metabolism / Q000473:pathology; D016393:Lymphoma, B-Cell / Q000134:cerebrospinal fluid / Q000473:pathology / Q000517:prevention & control*; D008577:Meningeal Neoplasms / Q000134:cerebrospinal fluid / Q000473:pathology / Q000517:prevention & control*; D008875:Middle Aged; D012008:Recurrence; D012074:Remission Induction; D000069283:Rituximab; D019139:Tumor Escape / Q000187:drug effects*
chemical_list: D000911:Antibodies, Monoclonal; D058846:Antibodies, Monoclonal, Murine-Derived; D018951:Antigens, CD20; D018956:CD5 Antigens; D000069283:Rituximab