a preceding period of anemia and abnormal blood cell production. these conditions were lumped together with other diseases under the term "refractory anemia". the first description of "preleukemia" as a specific entity was published in 1953 by block et al. the early identification, characterization and classification of this disorder were problematical, and the syndrome went by many names until the 1976 fab classification was published and popularized the term mds. michael brecker roald dahl nora ephron joe farrell pat hingle john kirby (attorney) joe morgan (cincinnati reds player) paul motian james w. nance robin roberts (newscaster) carl sagan susan sontag fred willard french-american-british (fab) classification in 1974 and 1975, a group of pathologists from france, the us, and britain produced the first widely used classification of these diseases. this french-american-british classification was published in 1976, and revised in 1982. it was used by pathologists and clinicians for almost 20 years. cases were classified into five categories: icd-o name description m9980/3 refractory anemia (ra) characterized by less than 5% primitive blood cells (myeloblasts) in the bone marrow and pathological abnormalities primarily seen in red cell precursors m9982/3 refractory anemia with ring sideroblasts (rars) also characterized by less than 5% myeloblasts in the bone marrow, but distinguished by the presence of 15% or greater of red cell precursors in the marrow being abnormal iron-stuffed cells called "ringed sideroblasts" m9983/3 refractory anemia with excess blasts (raeb) characterized by 5–19% myeloblasts in the marrow m9984/3 refractory anemia with excess blasts in transformation (raeb-t) characterized by 5–19% myeloblasts in the marrow (>20% blasts is defined as acute myeloid leukemia) m9945/3 chronic myelomonocytic leukemia (cmml), not to be confused with chronic myelogenous leukemia or cml characterized by less than 20% myeloblasts in the bone marrow and greater than 1*109/l monocytes (a type of white blood cell) circulating in the peripheral blood. (a table comparing these is available from the cleveland clinic.)