title: De novo CD5+ diffuse large B-cell lymphomas. A heterogeneous group containing an unusual form of splenic lymphoma.
abstract: We reviewed our institutional experience with de novo CD5+, large B-cell lymphomas to determine whether they represent a distinct entity and are related to CD5+ small B-cell disorders. We identified 13 cases with multiparameter flow cytometry over a period of 58 months (5% of large B-cell lymphomas) in 7 females and 6 males. Three groups were identified. Group 1 (2 cases) had diffuse splenic red pulp involvement with a distinctive cordal pattern of infiltration, no other clinical evidence of mass disease, microscopic disseminated disease on further workup, and an identical immunoglobulin-negative immunophenotype. Group 2 cases (7 cases) were clinically and morphologically heterogeneous and had an immunophenotype resembling mantle cell lymphoma (FMC7-positive, CD23-). Group 3 (4 cases) had miscellaneous immunophenotypes, including one closely resembling chronic lymphocytic leukemia. Cyclin D1 was positive in only 1 of 10 evaluable cases (group 2). We conclude that CD5+ diffuse large B-cell lymphomas are heterogeneous; most cases do not seem to be related to chronic lymphocytic leukemia or mantle cell lymphoma. However, we identified a subgroup of primary splenic CD5+ large B-cell lymphoma with diffuse red pulp involvement and believe this may represent a distinct clinicopathologic entity.
authors.affiliation: Dept of Pathology, University of Texas Southwestern Medical Center, Dallas 75390-9073, USA.
authors.forename: S H
authors.initials: SH
authors.lastname: Kroft
authors.forename: M S
authors.initials: MS
authors.lastname: Howard
authors.forename: L J
authors.initials: LJ
authors.lastname: Picker
authors.forename: M Q
authors.initials: MQ
authors.lastname: Ansari
authors.forename: D B
authors.initials: DB
authors.lastname: Aquino
authors.forename: R W
authors.initials: RW
authors.lastname: McKenna
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism; D000951:Antigens, Neoplasm / Q000378:metabolism; D019938:Cyclin D1 / Q000378:metabolism; D005260:Female; D016158:Genes, p53; D006801:Humans; D007124:Immunoenzyme Techniques; D016130:Immunophenotyping; D016393:Lymphoma, B-Cell / Q000145:classification / Q000378:metabolism / Q000473:pathology*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000145:classification / Q000378:metabolism / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D017354:Point Mutation; D013160:Splenic Neoplasms / Q000145:classification / Q000378:metabolism / Q000473:pathology*
chemical_list: D015703:Antigens, CD; D000951:Antigens, Neoplasm; D019938:Cyclin D1