title: Plasmablastic transformation of low-grade B-cell lymphomas: report on 6 cases.
abstract: Histologic transformation of low-grade B-cell lymphoma to diffuse large B-cell lymphoma is associated with poor prognosis. Although plasma cell differentiation is common in these lymphomas, an overt plasmablastic transformation (PBL-T) has been only rarely reported. We report 6 cases of PBL-T occurring in 3 chronic lymphocytic leukemias (CLL) and 3 follicular lymphomas. Five patients were men, and the mean age was 65 years (range, 52 to 72 y). None of them had history of immunodeficiency. In 3 cases the PBL-T occurred 34 to 85 months after the initial diagnosis, and in 3 it was detected simultaneously with the small cell component at diagnosis. All patients received chemotherapy after transformation, and 4 died 4 to 24 months after this diagnosis. In 3 cases, PBL-T occurred in an extranodal site. All PBL-Ts had immunoblastic morphology with admixed plasma cells, were CD20 and PAX5 negative, expressed λ light chain, and 5 were CD138 positive. All cases were negative for HHV8, and only 1 PBL-T was Epstein-Barr virus positive. Evidence of a clonal relationship between the small cell and PBL-T components was found in 5 cases. In 2 CLL cases, both components had 13q deletions, and in all follicular lymphoma cases both components harbored the t(14;18) translocation. MYC translocations were observed in 2 cases transformed from a CLL. In conclusion, PBL-T expands the clinicopathologic spectrum of the transformation of low-grade B-cell lymphomas. These transformed tumors are clinically, histologically, and phenotypically similar to primary plasmablastic lymphomas, but they are not associated with immunodeficiency and rarely have Epstein-Barr virus infection or MYC alterations.
authors.affiliation: Department of Hematopathology and Hematology, Hospital Clinic, Institut d'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), University of Barcelona, Barcelona, Spain.
authors.forename: Daniel
authors.initials: D
authors.lastname: Martinez
authors.forename: Alexandra
authors.initials: A
authors.lastname: Valera
authors.forename: Nhora Silva
authors.initials: NS
authors.lastname: Perez
authors.forename: Luz Fernanda
authors.initials: LF
authors.lastname: Sua Villegas
authors.forename: Blanca
authors.initials: B
authors.lastname: Gonzalez-Farre
authors.forename: Carla
authors.initials: C
authors.lastname: Sole
authors.forename: Eva
authors.initials: E
authors.lastname: Gine
authors.forename: Armando
authors.initials: A
authors.lastname: Lopez-Guillermo
authors.forename: Gaël
authors.initials: G
authors.lastname: Roue
authors.forename: Salome
authors.initials: S
authors.lastname: Martinez
authors.forename: Francesc
authors.initials: F
authors.lastname: Sant
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Warzocha
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Robak
authors.forename: Magdalena
authors.initials: M
authors.lastname: Czader
authors.forename: Neus
authors.initials: N
authors.lastname: Villamor
authors.forename: Lluis
authors.initials: L
authors.lastname: Colomo
authors.forename: Elias
authors.initials: E
authors.lastname: Campo
authors.forename: Antonio
authors.initials: A
authors.lastname: Martinez
mesh_terms: D000368:Aged; D002471:Cell Transformation, Neoplastic / Q000473:pathology*; D002869:Chromosome Aberrations; D002999:Clone Cells; D004273:DNA, Neoplasm / Q000032:analysis; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D016393:Lymphoma, B-Cell / Q000235:genetics / Q000401:mortality / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010954:Plasmacytoma / Q000473:pathology*
chemical_list: D004273:DNA, Neoplasm