Acute lymphocytic leukaemia with t(4;11): a clinical subentity

5 cases of ALL are reported with a t(4;11) chromosomal rearrangement, and 31 cases, investigated before therapy, are reviewed. The (4;11) translocation characterizes a subentity of ALL having the following main features, as compared with ALL in general: 1) Excessively poor prognosis, with a median survival of 6 months despite high remission rates. 2) Low median age of 10 months in children. 3) CNS involvement apparently occurs more frequently. 4) Median WBC is 12 times higher in adults and children, median per cent of blasts in blood 1.5 times higher in adults and 1.8 times higher in children. 5) Splenomegaly is present more frequently. 6) Surface markers are non-B, non-T. The incidence of t(4;11) in ALL varies greatly in the series published so far, from 0.04% to 12%.