Association of a chromosomal abnormality with lymphocytes having both T and B markers in a patient with lymphoproliferative disease.

The lymphocytes of a patient with leukemic lymphosarcoma were found to have an unusual surface phenotype in that they bound both sheep erythrocytes (a T cell marker) and complement-coated erythrocytes (a B cell marker) but lacked other B cell surface characteristics. Marker chromosomes were present in these cells, but not in other, phenotypically normal cells from the same patient. This case may provide a clue to the chromosomal origin of some lymphocyte surface markers in man.