Lymphoblastic lymphomas (LL) are rare and represent less than 2% of the malignant non-Hodgkin lymphomas (NHL). The distinction between a LL and an acute lymphoblastic leukaemia (ALL) is difficult; it is arbitrarily based on the percentage of medullary blasts. Above 20% of blasts, it is an ALL. In both cases, the same type of cells is affected: the lymphoblast. Thus the LL were treated either as aggressive NHL or as ALL. The results of the various clinical studies, have shown a best efficacy of ALL type treatments(in terms of overall survival and disease free survival). These treatments are based on an induction phase with reinforced cyclophosphamide and L-asparaginase, and a re-use of the first drugs after consolidation (delayed intensification). The prognostic factors of ALL are now better defined, determining risk groups. According to these prognostic indicators, the allograft could be proposed in first complete remission. Indicators are biological (hyperleukocytosis, chromosomal abnormalities as t(4;11), t(9;22), t(1;19) translocations), clinical (central nervous system involvement), evolutive (salvage therapy needed to obtain complete remission), consideration of early response (cortico-sensibility and chemo-sensibility) and molecular responses (residual disease). On the other hand, the prognostic factors of LL are not well known. This study should permit to better define them. So the prognostic indicators of ALL, in this study, will be decisional for the indication of allograft. This treatment is based on a parallel currently recruiting adult patients with ALL (protocol GRAALL 2003).
