Table 147.3Various Forms of Red Blood Cells

Macrocyte: Larger than normal (>8.5 μm diameter) (see Table 147.2)
Microcyte: Smaller than normal (<7 μm diameter). Often hypochromic (see Table 147.1)
Hypochromic: Less hemoglobin in cell. Enlarged area of central pallor (see Table 147.1)
Spherocyte: Loss of central pallor, stains more densely, often microcytic. Hereditary spherocytosis and certain acquired hemolytic anemias
Target cell: Hypochromic with central "target" of hemoglobin. Liver disease, thalassemia, hemoglobin D. Postsplenectomy
Leptocyte: Thin hypochromic cell with a normal diameter and decreased MCV. Thalassemia
Elliptocyte: Oval to cigar shaped. Hereditary elliptocytosis, certain anemias particularly B12 and folate deficiency
Schistocyte: Fragmented helmet-shaped or triangular red blood cell. Microangiopathic anemias, artificial heart valves, uremia, malignant hypertension
Stomatocyte: Slit-like area of central pallor in erythrocyte. Liver disease, acute alcoholism, malignancies, hereditary stomatocytosis, and artifact
Tear-shaped RBC: Drop-shaped erythrocyte, often microcytic. Myelofibrosis and infiltration of marrow with tumor, thalassemia
Acanthocyte: Five to 10 spicules of various lengths and at irregular intervals on surface of red cell
Echinocyte: Evenly distributed spicules on surface of red cell, usually 10 to 30. Uremia, peptic ulcer, gastric carcinoma, pyruvic kinase deficiency, preparative artifact
Sickle cell: Elongated cell with pointed ends. Hemoglobin S and certain types of hemoglobin C and 1

From: Chapter 147, Anemia

Cover of Clinical Methods
Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition.
Walker HK, Hall WD, Hurst JW, editors.
Boston: Butterworths; 1990.
Copyright © 1990, Butterworth Publishers, a division of Reed Publishing.

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