Most primary central nervous system diffuse large XXXX occurring in immunocompetent individuals belong to the nongerminal center subtype: a retrospective analysis of 31 cases.

@entity1 @entity588 @entity706 @entity149 @entity14546 @entity645 @entity2282 @entity4042 @entity406 @entity1892 @entity7513
@entity149 are rare neoplasms characterized by a dismal prognosis relative to other @entity706 . Approximately 98% of @entity149 are of B-cell origin, and most belong to the diffuse large B-cell type. Recently, diffuse large @entity1892 have been subcategorized into germinal center and nongerminal center types based on gene expression profiles and immunohistochemical expression of @entity2282 , @entity4042 , and @entity14546 . Studies have shown that the overall survival rate of the germinal center group is better than that of the @entity706 . In this study, 31 cases of @entity149 of the diffuse large B-cell type were retrieved, reviewed, and immunostained for @entity2282 , @entity4042 , @entity14546 , and Ki-67. Subclassification was carried out as described earlier, where @entity2282 and/or @entity4042 positivity and negativity for @entity14546 were considered characteristic of germinal center subtype and the opposite expression of nongerminal center subtype. Furthermore, the proliferative activity was semiquantitatively assessed using percent positive cells staining with Ki-67. Of the 31 cases examined, 26 (84%) were found to belong to the nongerminal center type. The Ki-67 index in these 26 cases ranged from 30 to 90% (mean, 69%). Five cases were categorized as the germinal center subtype. They had an Ki-67 index between 70 and 90% (mean, 78%). Interestingly, none of our @entity1 were known to be @entity645 positive. One @entity1 had a 10-year history of orthotopic liver transplant. We also performed fluorescence in situ hybridization analysis on @entity406 -fixed material and found that 38% of the cases where tissue was available had abnormalities of MYC/ @entity7513 and/or @entity7513 / @entity588 . We conclude that most primary central nervous system diffuse large @entity1892 are of the nongerminal center origin. Regardless of the germinal center status, all cases showed a high proliferative rate. A statistically significant difference in the overall survival between the two groups was not seen.
