Trong một sắt sideroachrestic thiếu máu hiện tại không có thể được sử dụng (achrestic = vô dụng). Đây là một chẩn đoán nghi ngờ khi nồng độ sắt trong huyết thanh được nâng lên hoặc trong phạm vi bình thường cao, và khi các hồng cầu mạnh mẽ anisocytosis, poikilocytosis (giảm trung bình MCV), | Hypochromic Anemias 137 Hypochromic Sideroachrestic Anemias Sometimes Normochromic or Hyperchromic In a sideroachrestic anemia existing iron cannot be utilized achrestic useless . This is a suspected diagnosis when serum iron levels are raised or in the high normal range and when the erythrocytes show strong anisocytosis poikilocytosis with reduced average MCV polychromophilia and in some cases also basophilic stippling Fig. 46 . This suspicion can be further illuminated by bone marrow analysis. Unlike in infectious toxic anemias the red cell series is well represented. Iron staining of the bone marrow is the decisive diagnostic test causing the iron-containing red precursor cells sideroblasts to stand out hence the term sideroblastic anemia. The iron precipitates often collect in a ring around the nucleus ringed sideroblasts . By far the majority of the idiopathic sideroachrestic anemias as they used to be called are myelodysplasias see p. 106 . Only a few of them appear to be hereditary or have exogenous triggers alcoholism lead poisoning . Theml Color Atlas of Hematology 2004 Thieme All rights reserved. Usage subject to terms and conditions of license. 138 Erythrocyte and Thrombocyte Abnormalities Hypochromic Anemia with Hemolysis Thalassemias A special form of hypochromic anemia mostly affecting patients of Mediterranean descent presents with normal erythrocyte count decreased MCH and clinical splenomegaly. The smear displays erythrocytes with central hemoglobin islands target cells . These cells do not necessarily predominate in the CBC the most revealing field views show at most 50 target cells in addition to clear anisocytosis and frequent basophilic stippling. Occasional normoblasts give a general indication of increased erythropoiesis. Although target cells are also nonspecific since they can occur in such conditions as severe iron deficiency or obstructive jaundice this overall picture should prompt hemoglobin electrophoresis. The sample consists of .
