Primary Central Nervous System Lymphoma in Korea

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.

Primary Central Nervous System Lymphoma in Miyazaki, Southwestern Japan, a Human T-Lymphotropic Virus Type-1 (HTLV-1)-Endemic Area: Clinicopathological Review of 31 Cases

“…10 In other East Asian countries, the T-PCNSL prevalence was reported as 16. 7% in Korea 11 and 1% in Taiwan. 12 Using the criteria described in the WHO Classification of Tumours of the Haematopoietic and Lymphoid Tissues, we diagnosed 29 cases as primary DLBCL of the CNS and the other two cases as low-and highgrade B-cell lymphoma (not otherwise specified).…”

Primary Central Nervous System T-Cell Lymphoma of the Brain

“…Cystic degeneration with necrosis and hemorrhage are consistent within both populations [3]. T-cell PCNSL has consistent histological features including small nuclei, bland morphology without high grade features, heterogeneity and angiocentricity [2,3,5,[10][11][12]. The histopathologic appearance of T-cell PCNSL can include loosely scattered cells without solid mass formation and frequent perivascular infiltration [2].…”

“…It remains a very rare entity despite a gradual increase in global incidence. The reason for the initial rise in incidence had been linked to a growing immunocompromised population, in part due to, acquired immune deficiency syndrome (AIDS), increased prevalence of human immunodeficiency virus (HIV) infection, organ transplantation and the elderly [2][3][4]. However, due to advances in antiretroviral therapy the incidence of PCNSL in the immunocompromised population has been decreasing, yet the incidence of PCNSL in the immunocompetent population has been rising without clear explanation.…”

“…However, due to advances in antiretroviral therapy the incidence of PCNSL in the immunocompromised population has been decreasing, yet the incidence of PCNSL in the immunocompetent population has been rising without clear explanation. The overall occurrence rate of PCNSL is 1:100,000, which accounts for 3-6% of all primary brain neoplasms [2,5]. The occurrence rate of B-cell lymphomas is much more common than T-cell lymphomas and this concept hold true both in systemic and CNS presentation of lymphomas [2,5,6].…”

“…The overall occurrence rate of PCNSL is 1:100,000, which accounts for 3-6% of all primary brain neoplasms [2,5]. The occurrence rate of B-cell lymphomas is much more common than T-cell lymphomas and this concept hold true both in systemic and CNS presentation of lymphomas [2,5,6]. Of the cases of PCNSL reported, 98% are B-cell and 2% are T-cell lymphomas [3,6].…”