Acute myeloblastic leukemia developing in patients with mediastinal lymphoblastic lymphoma.

Of three patients with mediastinal malignant lymphoma, lymphoblastic type, at the time of diagnosis one also had acute myeloblastic leukemia (AML), and the other two had blood and bone marrow findings indicative of acute lymphoblastic leukemia (ALL). The latter two patients developed the hematologic picture of AML less than eight months later. In all cases, AML was confirmed by cytochemical studies of peripheral blood and bone marrow cells. Autopsy of two of the patients revealed only AML. The myeloid nature of the proliferative cells was demonstrated with the naphthol-ASD-chloroacetate stain (NCA) on postmortem tissue sections. This study further supports the hypothesis of a common origin of neoplastic lymphoid and myeloid cells from pluripotent bone marrow stem cells.