E-rosette positive acute lymphoblastic leukaemia in adolescents and adults.

E-rosetting of leukaemic blast cells is one of the markers of T-cell acute lymphoblastic leukaemia (ALL). In children, E+ ALL has a bad prognosis. In adults, data are scarce. This report provides information on 25 E+ ALL adult patients who have a minimum follow-up time of 36 months. Twenty-two of 25 patients (88%) achieved complete remission (CR) (median duration 16 months), and six of them were alive, relapse-free, and off therapy after 36-81 months, with a 26% projected 6-year relapse-free survival. In 97 patients with E-SmIg- ALL, who were treated at the same Institutions, over the same period of time, and by the same modalities, the outcome of therapy was almost identical: CR 80%, median duration of first CR 15 months, projected 6-year relapse-free survival 15%. The white blood cell (WBC) count at presentation influenced significantly and to the same degree first CR length in both E+ and E- cases. In this adult series, WBC count was not as high as in children. Moreover, a high Hb concentration, a very high WBC count, lymphadenomegaly, and mediastinal involvement, were found more frequently in adolescents and young adults than in adults. Based on these data, it is suggested that in adults E-rosetting as such is not a marker of a poorer prognosis, that some of the typical features of children E+ ALL weaken with age, and that in adults the disease can have a less aggressive character.