Myelofibrosis
Fibrosis (spontaneous scarring) of the bone marrow.
This can be associated with a variety of diseases, primarily myeloproliferative (pre-leukemic) disorders.
Sometimes used interchangeably with agnogenic myeloid metaplasia.
Myelofibrosis is characterized by significant anemia and an enlarged spleen.
Acute myelofibrosis is a distinct disorder characterized by acute inadequate blood cell production (pancytopenia), marrow fibrosis, but no enlargement of the spleen or liver.