Chronic erythremic myelosis profiling a refractory anemia.

Chronic erythremic myelosis is a myeloproliferative disorder of unknown etiology that is characterized by refractory macrocytic anemia and marked megaloblastoid erythroid hyperplasia of the bone marrow. Ferrokinetic and cytologic evidence indicates that the disorder demonstrates ineffective erythropoiesis. Certain cytochemical tests may help both to substantiate the diagnosis and to provide insight into some of the biochemical abnormalities in the erythroid precursors. Therapeutic trials of androgen or pyridoxine (vitamin B6) or both may be of value in some cases but ineffective in others, and some patients may require administration of blood transfusions. Why an erythroid disorder characterized by a uniquetype of megaloblastoid erythropoiesis should be the forerunner of acute leukemia is one of the many unanswered questions in this often therapeutically frustrating disorder.