Burkitt's lymphoma in Japan.

The clinicopathological features of 18 Japanese patients with Burkitt's lymphoma are reviewed. Six patients were 12 years of age or younger. Seven patients presented with abdominal masses and seven with jaw tumours. Thirteen patients manifested blood and/or marrow involvement at the time of initial diagnosis (five patients) or later in the course of the disease (eight patients). Most of the patients had a rapid clinical course in spite of combination chemotherapy. The malignant cells from all 17 patients examined exhibited a B-cell phenotype; the surface immunoglobulin was IgM in 15 and IgG in two. Two patients had tumours positive for Epstein-Barr virus-determined nuclear antigen while the other 13 patients tested lacked this antigen in their tumours. Chromosome analysis revealed a t(8;14) translocation in 11 patients, a 14q+ without an identifiable donor chromosome in two, a t(2;8) translocation in two, and a t(8;22) translocation in one.