Myeloproliferative diseases.

The various myeloproliferative diseases have different symptoms, therapeutic problems, and prognoses. The most common of these disorders appears to be agnogenic myeloid metaplasia, which primarily affects older persons. The five-year survival rate at the Mayo Clinic for these patients is 58%, and the prognosis depends on the presence of symptoms, anemia, and thrombocytopenia and on the size of the liver. Androgen therapy is often necessary to control anemia, and splenectomy may be indicated.