ANGIOCENTRIC IMMUNOPROLIFERATIVE LESIONS OF THE LYMPH-NODE

Clinicopathologic features in 14 cases of lymph node-involved angiocen tric immunoproliferative lesions (AILs) are reported, They were select ed from 900 cases of lymphoproliferative disorders registered at the D epartment of Pathology, Fukuoka University, Four cases showed a histol ogic feature of AIL grade II (AIL-II) and 10 had angiocentric lymphoma (AIL-III), Immunohistologically, transformed B cells were mixed with a large number of small T cells in AIL-II. In AIL-III, there were five cases with B-cell lymphoma, and three had peripheral T-cell lymphoma with no expression of natural-killer (NK)-associated antigens. In the remaining two cases, lymphoma cells expressed both T-cell- and NK-asso ciated antigens. These findings indicate that lymph node-involved AILs are rarely occurring (1.6%) and phenotypically different from sinonas al and cutaneous AILs, Furthermore, NK-associated antigen-positive AIL s were found to rarely involve the lymph node, For Epstein-Barr virus (EBV) infection, seven cases of AILs showed many atypical lymphocytes that were positive for EBV-encoded RNA (EBER-1) by using the in situ h ybridization analysis, Among them, six cases had latent membrane prote in (LMP) positive and EBV nuclear antigen 2 (EBNA-2) negative atypical lymphocytes. The pattern of latent EBV infection was similar to that of Hodgkin's disease, but differed from those of sinonasal T-cell lymp homa and other subtypes of non-Hodgkin's lymphoma. Clinically, 12 pati ents, including all 4 AIL-II, died within 22 months of the onset of th e disease, despite intensive therapy, suggesting that lymph node-invol ved AILs have a poor prognosis.