Manual of basic techniques for a health laboratory - libdoc.who.int

9. Haematology 307Fig. 9.77 Normal erythrocytesFig. 9.78 Target cellsFig. 9.79 Sickle cellsFig. 9.80 MicrocytesSickle cells (Fig. 9.79)Shape: elongated and narrow, often with one or both ends curved and pointed.Seen in sickle-cell anaemia and sickle-cell thalassaemia, along with nucleated erythrocytes,target cells and often macrocytes.Microscopic examination of sickle cells in wet preparations is described in section9.11.4.Microcytes (Fig. 9.80)Size: small (about 5mm).Seen often in iron-deficiency anaemia, sideroblastic anaemia and thalassaemias.Must be distinguished from spherocytes (see below).Macrocytes (Fig. 9.81)Size: large (9–10mm).Seen in macrocytic anaemias caused by folic acid deficiency, vitamin B 12deficiencyand iron-deficiency anaemia, and in certain liver diseases. Must be distinguishedfrom reticulocytes (see below).