CMML: as a type of MDS/MPD in WHO classification; clinical outcome is more closely related to bone marrow primitive cell % compared to peripheral blood mononuclear cell count (P234). 5q-syndrome: independent clinical type in WHO classification with a more inert clinical course, lower conversion rate of AML, macrocytic anemia, thrombocytosis and megakaryocytic pathological hematopoiesis. Pure iron granulocytic anemia (PSA): iron granulocytic anemia with pathological hematopoiesis of red lineage precursor cells only (RARS in WHO classification) has a better survival (77% overall survival at 3 years) than those with pathological hematopoiesis accumulating both granulocytic and macrocytic lineages (56% overall survival at 3 years), even with a low rate of distant AML transformation. Secondary MDS: previous chemotherapy and increased environmental pollution can lead to increased morbidity; the vast majority of patients presenting with multiple chromosomal abnormalities have a worse prognosis than primary MDS. Hypoproliferative MDS: <15% of MDS bone marrow biopsies show hypoproliferation (<30% hematopoietic cells in those <60 years; <20% hematopoietic cells in those >=60 years); megakaryocytes with or without myelopathic hematopoiesis or the presence of an excess of primitive cells; often the allogeneic cytopenia is more severe and thus may be difficult to differentiate from aplastic anemia: typical MDS cytogenetic abnormalities are helpful; No particular age range, difference in FAB type and prognosis; may respond to immunosuppressive therapy. Fibrotic MDS: >50% of patients have increased myelofibrotic component, but <15% have significant myelofibrosis; all FAB types; secondary MDS is more common; active myeloproliferation with myelofibrosis; peripheral blood shows features of allogeneic cytopenia and pathological hematopoiesis and sometimes red-white juvenile phenomenon; organomegaly is uncommon; usually rapid deterioration.