Abstract
Pleomorphic T-cell leukaemia occurring in an adult Caucasian patient is described. The leukaemia cells expressed both antigenic determinants (T4 and T8) normally detected separately on either helper or suppressor cells. They functioned as helper cells and there was evidence of unbridled antibody production. It is possible that a distinctive subtype of pleomorphic T-cell leukaemia occurs in Caucasian patients.