Mixed-lineage leukemia revisited: acute lymphocytic leukemia with
myeloperoxidase-positive blasts by electron microscopy [see comments]
HM Kantarjian, C Hirsch-Ginsberg, G Yee, Y Huh, EJ Freireich and S Stass
Department of Hematology, University of Texas, M.D. Anderson Cancer Center,
Houston 77030.
Seven adult patients with untreated acute lymphocytic leukemia (ALL) who
manifested 5% to 40% myeloperoxidase (MPO)-positive blasts by electron
microscopy (EM) are reported. Six patients had an L2 morphology, and one
had an L1 morphology by the French-American-British (FAB) classification.
The immunophenotype was T cell in four patients. Molecular analysis showed
rearrangement of the immunoglobulin JH in four patients, three of them also
having rearrangement of the T-cell receptor beta or gamma. Induction
chemotherapy with vincristine- doxorubicin-dexamethasone (VAD) produced a
complete remission in five of six patients (83%). Our findings suggest the
existence of a previously undescribed subtype of mixed-lineage leukemia,
which by morphology and immunophenotype often appears as T-cell ALL but
exhibits MPO-positive blasts by EM.
Volume 76,
Issue 4,
pp. 808-813,
08/15/1990
Copyright © 1990 by The American Society of Hematology
