Chronic myelogenous leukemia. Development of blast crisis with both lymphoid and myeloid features
K. M. Skubitz, P. R. Craddock, D. J. Weisdorf, J. E. Niedel, T. W. LeBien, J. H. Kersey, R. D. Brunning, J. L. Parkin, P. J. Flynn and D. E. Hammerschmidt
A 50-year-old man had chronic myelogenous leukemia and entered a blast
crisis that was both morphologically and histochemically lymphoid. The
blasts contained terminal deoxyribonucleotidyl transferase and expressed
lymphoblastic leukemia-associated antigen. He rapidly entered remission
with vincristine sulfate and prednisone therapy. Nevertheless, his blasts
displayed a marker generally considered unique to myeloid cells: they
selectively bound the granulocyte chemotaxin N-formyl-Met-Leu-Phe. In
addition, some cells contained granules resembling those of basophils or
mast cells. Such mixed myeloid-lymphoid features in chronic myelogenous
leukemia blast cells may reflect malignant transformation of a stem cell
capable of both myeloid and lymphoid differentiation, or they may reflect
the dedifferentiation as a feature of malignant change.