Pathological study on nasal T-cell lymphoma in East Asia

点击翻译按钮获取中文摘要

Nasal T-cell lymphoma (NTL) is one of diseases clinically showing lethal midline granuloma. Histologically NTL shows polymorphous pattern of cellular proliferation, thus also having been called as polymorphic reticulosis (PR). Our previous study showed the incidence rate of NTL per 100, 000 patients visiting Ear-Nose-Throat Clinic was 8.0 in Japan other than Okinawa, 27.4 in Okinawa, 40.8 in Seoul (Korea), and 9.8 in Shanghai (China), which were higher than that in England. Recent study suggested the etiological role of Epstein-Barr virus (EBV) for development of NTL.In the current study, correlation between the incidence rate of NTL and frequency of EBV positivity in the proliferating cells was examined. For this purpose, nasal lymphoma in Okinawa (20 cases) and Osaka (32 cases) were selected for histologic and immunohistochemical studies. Presence of EBV was examined by the PCR and in situ methods.Immunohistochemically, 27 cases were B cell type (20 Osaka, 7 Okinawa), 20 were T cell type (9 Osaka, 11 Okinawa), and 5 were undefined. EBV genome was found in 6 of 15 cases (40%) and 4 of 5 cases (80%) of nasal B and T cell lymphomas in Osaka and 3 of 7 cases (43%) and 7 of 7 cases (100%) in Okinawa, showing the different frequencies of positivity by immunophenotype but not by district. These findings suggest that EBV might be a causative factor in sino-nasal lymphoma of not only T cell but also B cell type in Japan. Meanwhile the higher incidence of NTL in Okinawa than in Osaka could not be explained by the different positivity ratio of EBV in the tumors. Other factors such as environmetal or life style on the development of NTL might be important.