title: Primary central nervous system lymphoma in Korea: comparison of B- and T-cell lymphomas.
abstract: The great majority of primary central nervous system lymphoma (PCNSL) is known to be of B-lineage, with T-cell PCNSL (T-PCNSL) accounting for <5%. We report an unusually high incidence of T-cell lymphoma among the PCNSLs originated in a large general-care hospital in the metropolitan Seoul area. PCNSLs (n = 42) accrued from April 1995 through June 2001 were reviewed for histologic and clinical features, and immunohistochemical staining was done for CD3, CD20, CD4, CD8, Bcl-6, and CD10. Clonal rearrangements of the TCR-gamma and IgH genes were studied with semi-nested PCR in all seven cases of T-PCNSL and seven of 35 B-cell PCNSL (B-PCNSL). Formalin-fixed, paraffin-embedded specimens were used in all these studies. By immunohistochemical staining and molecular studies, seven cases (16.7%) were diagnosed as T-PCNSL, each displaying clonal rearrangement of the TCR-gamma gene, and 35 (83.3%) as B-PCNSL. Radiologically, T-PCNSL was significantly correlated with the superficial and subcortical lobar location (p <0.001), solitary mass formation (p = 0.001), presence of rim enhancement (p <0.001), and peritumoral edema (p = 0.029). Involvement of cerebrospinal fluid was observed only in B-PCNSL (n = 17) but not in T-PCNSL (p = 0.010). Histologically, T-PCNSL was characterized by a population of mixed predominantly small- and occasionally medium-sized cells (p <0.001), which were loosely scattered without forming a solid mass (p = 0.024), and perivascular infiltration was frequent (p = 0.007), in contrast to predominantly large cells of B-PCNSL, i.e., diffuse large B-cell lymphoma (DLBCL), in which the cells tended to aggregate to form monomorphous sheets (p = 0.024). In T-PCNSL, staining for CD8 was positive in five, including one with coexpression of CD4, and two were negative for CD4 and CD8. Of 24 DLBCLs tested, the pattern of Bcl-6+ tumor cells was diffusely dense, similar to that of the germinal center in nine cases (37.5%), with coexpression of CD10 in three of the nine cases. T-PCNSL accounted for 16.7% of the PCNSLs; thus, in Korea it may not be as rare as previously known. The T-PCNSL presented with certain clinical and pathologic features that were distinct from B-PCNSL and displayed preponderance of CD8 expression. DLBCL of the germinal center B-cell derivation defined by bcl-6 expression comprised 37.5% of DLBCL of the brain.
authors.affiliation: Department of Diagnostic Pathology, Sungkyunkan University College of Medicine, Seoul, Korea.
authors.forename: Jong Sun
authors.initials: JS
authors.lastname: Choi
authors.forename: Do-Hyun
authors.initials: DH
authors.lastname: Nam
authors.forename: Young Hyeh
authors.initials: YH
authors.lastname: Ko
authors.forename: Jin Won
authors.initials: JW
authors.lastname: Seo
authors.forename: Yoon-La
authors.initials: YL
authors.lastname: Choi
authors.forename: Yeon Lim
authors.initials: YL
authors.lastname: Suh
authors.forename: Howe J
authors.initials: HJ
authors.lastname: Ree
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015703:Antigens, CD / Q000032:analysis; D014408:Biomarkers, Tumor / Q000032:analysis; D001932:Brain Neoplasms / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D004273:DNA, Neoplasm / Q000032:analysis; D005260:Female; D015329:Gene Rearrangement, T-Lymphocyte / Q000235:genetics; D006801:Humans; D007124:Immunoenzyme Techniques; D007143:Immunoglobulin Heavy Chains / Q000235:genetics; D007723:Korea; D016393:Lymphoma, B-Cell / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D016403:Lymphoma, Large B-Cell, Diffuse / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D016411:Lymphoma, T-Cell, Peripheral / Q000737:chemistry / Q000235:genetics / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000235:genetics; D012189:Retrospective Studies
chemical_list: D015703:Antigens, CD; D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; D007143:Immunoglobulin Heavy Chains; D016692:Receptors, Antigen, T-Cell, gamma-delta