Leukemic relapse as T-cell acute lymphoblastic leukemia in a patient with acute myeloid leukemia and a minor T-cell clone at diagnosis

Background and Objectives. Lineage classification needs to be established b efore starting chemotherapy in acute leukemias. In some cases, mixed popula tions can be found and these are differentiated by antigenic expression pat terns. Design and Methods. We report the case of a patient with acute myelogenous leukemia whose relapse was classified as T-acute lymphoblastic leukemia. Results. Flow cytometry analysis at diagnosis enabled us to identify a mino r T-cell subclone which progressively increased and became dominant at rela pse. There were no changes at cytogenetic and molecular levels. Interpretation and Conclusions. This case illustrates the usefulness of mul tiparametric flow cytometry for assessing minor leukemic populations. (C) 2 000, Ferrata Storti Foundation.