[Primary extranodal malignant lymphoma]

Primary extranodal lymphoma with high frequency and/or unique feature in Japan is discussed. Waldeyer ring lymphoma is most frequent(30%). Most tumors consist of diffuse, large cell type of B cell. CHOP followed by radiation achieved 94.1% of 5 years survival. Gastrointestinal lymphoma is another frequent lymphoma. Surgical rejection followed by chemotherapy and radiation therapy achieved high response. Pyothorax-associated lymphoma is a unique entity reported in Japan. EB-virus and artificial pneumothorax are related to its occurrence. In intravascular lymphomas, lymphoma cells regionally exist in small vessel and are diffuse, large cell type of B cells. Brain is frequently involved. Bone lymphoma is found in 4-8%. The prognosis depend on the site and 5 year relapse-free survival is 70%.