Primary lymphoma arising in the nasal cavity among Japanese

AIMS: Most lymphomas arising in the nasal cavity are thought to be of natural killer (NK) cell origin. However, some reports indicate that T- and B-cell lymphomas may also primarily arise in the nasal cavity. We therefore studied lymphomas arising in the nasal cavity both histologically and immunohistochemically. METHODS AND RESULTS: Of the 32 cases investigated, 20 cases were also available as fresh frozen specimens. We diagnosed 31 cases as extranodal NK/T-cell lymphoma and one as plasmacytoma. The neoplastic cells were immunoreactive for CD3 (polyclonal) 31/31, LMP-1 12/31, CD20 (L26) 0/31, granzyme B 30/31, TIA-1 30/30, CD56 (123C3) 29/31, CD4 0/31 and CD8 3/31. In situ hybridization for Epstein-Barr virus-encoded small RNA-1 (EBER-1) was detected in 31/31. In frozen tissue sections, neoplastic cells mostly showed CD3 (Leu4)-, CD4 (Leu3a)-, CD5 (Leu1)-, CD8 (Leu2)-, CD16 (Leu11)-, CD56 (Leu19)+, betaF1-, TCRdelta1-, perforin+, CD94+ phenotypes. These immunohistochemical findings indicate their NK cell origin. In three cases, neoplastic cells were positive for CD8. In one of these cases, neoplastic cells were positive for CD8beta and Valpha24, suggesting their NKT-cell origin. CONCLUSIONS: Our present study indicates that primary lymphomas arising in the nasal cavity are mostly of NK cell derivation. Our present study also suggests that a small number of cases are derived from NKT-cells.