[Acute osteomyelofibrosis. An overview and 2 personal cases].

Two cases of acute myelofibrosis are described which exemplify diagnostic and therapeutic possibilities in this clinical and morphologic entity. Delimiting criteria against other diseases with bone marrow fibrosis are also presented. This malignant myeloproliferative disorder is characterized by acute onset, minimal or absent splenomegaly, blood cytopenias with a highly variable percentage of blast cells in circulating blood, often unimpressive tear-drop poikilocytosis, intense marrow fibrosis, and a rapid clinical course. In one case, typical proliferation of all three hematopoietic cell lines was lacking and proliferating blast cells could be classified as myeloblasts/promyelocytes histochemically. In the other case, a single course of intensive combination chemotherapy resulted in marked dissolution of the marrow fibrosis and prolonged survival in partial remission.