An eight year old English boy presented with an abdominal undifferentiated 'Burkitt-like' lymphoma. Lymphoma cells from ascitic fluid were cultured on a human embryo fibroblast feeder layer and, after a short lag period, a cell line (DH-BL) was established which, like the original tumour, was both negative for the Epstein-Barr nuclear antigen (EBNA) and expressed a monoclonal pattern of surface immunoglobulin (alpha lambda). DH-BL also possessed the Burkitt-related 8:14 chromosome translocation in all metaphases analysed; no other chromosomal abnormalities were present. The cell surface phenotype of the original biopsy cells and the cultured tumour cells in early passage were investigated using a panel of monoclonal antibodies to B lineage-associated antigens. These antibodies had recently been used to characterise African 'endemic' Burkitt's lymphoma (BL) biopsy cells and their derived cell lines. The cell surface phenotype of this English EBNA negative Burkitt-like lymphoma biopsy was indistinguishable from that previously shown by biopsies of EBNA positive endemic BLs. It therefore appears that both the endemic and sporadic forms of BL, as illustrated by this case, may be derived from the same subset of progenitor cells.