[Immunophenotype of nasal T-cell lymphoma]

The immunophenotype of 14 cases of nasal T/NK-cell lymphomas in Southern Japan were determined by double labelling with EBER-1 in situ hybridization and immunohistochemical staining. In all cases, EBER-1-positive tumor cells were positive for CD3 epsilon in their cytoplasms, but negative for CD4 and CD8. EBER-1-negative infiltrating cells were positive for CD3, CD4, and CD8 in 12 out of 14 cases. Therefore, the tumor cells in these nasal T/NK-cell lymphomas seem to be activated NK cells.