AGNOGENIC myeloid metaplasia is a disorder of unknown etiology. Most authors consider the disease as a myeloproliferative process.1,2 It is characterized by moderate-to-massive splenomegaly with active hematopoiesis in the spleen. Peripheral blood exhibits erythrocytic changes such as normoblasts and teardrop poikilocytes. Evidence of myeloid immaturity, bizarre or giant platelets, and megakaryocytic fragments in the peripheral blood also may be seen. The bone marrow is fibrotic in most patients, but that of some patients is normocellular or hypercellular.
Symptomatic patients present with manifestations of anemia, bleeding, or abdominal pain secondary to splenic infarction or a huge spleen. The basic management of this disorder consists of control of these major symptoms through the use of transfusions, androgens, busulfan (Myleran), adrenal steroids, splenic irradiation, and splenectomy.
The purpose of this communication is to review the natural history of this disorder and the influence of various therapies in a large series