Global histone modification profiles are well conserved between normal B lymphocytes and neoplastic counterparts.

The identification of cell type is essential in diagnostic tumor histopathology. We hypothesized that some patterns of global histone modification are specific to both particular cell types of non-neoplastic tissues and their neoplastic counterparts. To examine the hypothesis in lymphoid cells, global histone modification patterns of germinal center and mantle zone B cells in reactive lymphoid hyperplasia (RLH) were compared with those of follicular lymphoma (FL) and mantle cell lymphoma (MTL) cells by immunohistochemistry. We revealed that FL cells and MTL cells exhibited the similar histone modification pattern to that of germinal center B lymphocytes and mantle zone B lymphocytes in RLH, respectively. These results indicate that global histone modification profiles specific to non-neoplastic germinal center B lymphocytes and mantle zone B lymphocytes are well conserved in corresponding neoplastic lymphoma cells, and suggest that they will be indicative of tumor cell type at least in B cell lymphoma.