Blastic phase of agnogenic myeloid metaplasia simulating malignant lymphoma

A patient with angogenic myeloid metaplasia in blastic transformation with unusually prominent lymphadenopathy simulating lymphoma is described. Interestingly, the initial evidence of myeloblastic transformation was present in the lymph nodes but not in the marrow. Serial bone marrow biopsies showed fibrosis throughout the course of the disease, in spite of a gradual increase in the percentage of peripheral blood myeloblasts. Aneuploidy with a marker chromosome and a Philadelphia-like chromosome was present in the lymph node, bone marrow, and peripheral blood cells. The literature is reviewed regarding the incidence of prominent lymphadenopathy and chromosome abnormalities in agnogenic myeloid metaplasia and other myeloproliferative disorders.