Erythrophagocytosis in de novo-philadelphia-positive acute leukemia of ambiguous lineage.

Erythrophagocytosis by neoplastic cells in acute leukemia has been most frequently associated with FAB M4 and M5 subtypes, with the t(8;16) and with C-MOZ rearrangements, however it is exceptional in acute lymphoblastic leukemia and has not been previously reported in Philadelphia-positive (Ph+) acute leukemia. We herein present a case of Ph+ acute leukemia of ambiguous lineage in which erythrophagocytosis is an outstanding feature. The implications between the different postulated leukemogenic pathways and the hypothesized mechanism of erythrophagocytosis are concisely reviewed and discussed.