A Comparative Electron Microscopic Study of Refractory and Alcoholic Sideroblastic Anaemia

S ummary . A comparative electron microscope study of refractory and alcoholic sideroblastic anaemia has been performed. In all cases the mitochondria were infiltrated by dense clumps of iron which were located between the cristae in the matrix. Resolution of the clumps revealed the presence of a finely granular, threadlike precipitate. In alcoholic patients iron in the form of ferritin was found in cytoplasmic heterogeneous bodies. The latter, being rather numerous in one case, contribute to the positive Perls reaction. Based on their morphological diversity and resemblance to hepatic dense and lytic residual bodies, it is assumed that these bodies may be lysosomes involved in autophagy. Coated vesicles and smooth thick vesicles, with or without ferritin, were seen in all cases, as were ferritin aggregates.