Sideroblastic and megaloblastic change.

Introduction THE simultaneous occurrence in the bone marrow of megaloblasts and ring-sideroblasts may result from a variety of causes. In a series of seventy patients with sideroblastic anaemia, MacGibbon and Mollin (1965) observed megaloblastic change in 544O of cases of primary sideroblastic anaemia, and in 74YO of cases of secondary sideroblastic anaemia. The megaloblastic change was attributed to folate deficiency which they detected in 80°/ of both primary and secondary forms. A favourable response to folate therapy was evident in 40Y. of the patients. In pernicious anaemia, also, small numbers of ringsideroblasts are frequently demonstrated in the late megaloblasts although treatment with vitamin B12 results in their rapid disappearance. A further cause of concurrent sideroblastic and megaloblastic change is illustrated by the following case.