title: Secondary CD5+ diffuse large B-cell lymphoma not associated with transformation of chronic lymphocytic leukemia/small lymphocytic lymphoma (Richter syndrome).
abstract: Few cases of secondary CD5+ diffuse large B-cell lymphoma (DLBCL) that are not Richter syndrome have been reported previously. We report 9 cases of non-Richter syndrome secondary CD5+ DLBCL. Among 529 cases of DLBCL, 38 (7.2%) were CD5+ DLBCL, including 9 of secondary CD5+ DLBCL. Five cases gained CD5 expression during the clinical course of DLBCL (group 1). Three cases showed transformation from CD5- low-grade B-cell lymphoma to CD5+ DLBCL (group 2). The remaining case showed coexistence of CD5+ DLBCL and CD5+ follicular lymphoma. The clonal relationships of CD5- and CD5+ tumors were confirmed in all 4 available cases. Cases of secondary CD5+ DLBCL that were not Richter syndrome were classifiable into 3 groups. Groups 1 and 2 showed the gain of CD5 during the clinical course or transformation of the tumors, suggesting that CD5 expression is closely associated with the progression of B-cell lymphoma.
authors.affiliation: Clinical Laboratory Division, National Cancer Center Hospital, Tokyo, Japan.
authors.forename: Akiko Miyagi
authors.initials: AM
authors.lastname: Maeshima
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Taniguchi
authors.forename: Junko
authors.initials: J
authors.lastname: Nomoto
authors.forename: Dai
authors.initials: D
authors.lastname: Maruyama
authors.forename: Sung-Won
authors.initials: SW
authors.lastname: Kim
authors.forename: Takashi
authors.initials: T
authors.lastname: Watanabe
authors.forename: Yukio
authors.initials: Y
authors.lastname: Kobayashi
authors.forename: Kensei
authors.initials: K
authors.lastname: Tobinai
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Matsuno
mesh_terms: D018956:CD5 Antigens / Q000096:biosynthesis*; D002471:Cell Transformation, Neoplastic; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000473:pathology*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000145:classification* / Q000378:metabolism* / Q000473:pathology*; D016133:Polymerase Chain Reaction
chemical_list: D018956:CD5 Antigens