ANISOCYTOSIS – variation in RBC size Normocyte = measures 6.2 – 8.2 u (7.2 u) Microcyte = less than 6 u Macrocyte = measuring 8 – 9 u Megalocyte = measures 9 – 12 u
Normochromic – peripheral ring of Hgb surrounding an area of pallor Hypochromic – thin peripheral Hgb ring with an enlarged area of pallor Ex. Annulocyte Hyperchromic – RBC appears thicker than normal, stains evenly through out the cell and lacks the area of pallor. Ex. Spherocyte
Anisochromia / dimorphic anemia – blood picture showing both normochromic and hypochromic red blood cells. Ex. Sideroblastic anemia, blood transfusion and on Iron therapy Polychromasia / polychromatophilia – a bluish gray color of the RBC on Wright’s stain smear due to presence of RNA.
Residual RNA indicates immaturity of cell On supravital staining with Brilliant Cresyl Blue or New Methylene Blue, the RNA combines with the stain to form the dye- ribonuceloprotein complex which appears as a lacework pattern called the reticulum and thus calling the said cell as RETICULOCYTE. Polychromasia = Reticulocyte
Target cell – also called the leptocyte ,the Mexican hat cell or the codocyte An RBC with a peripheral ring of Hgb plus a central condensation of Hgb in the area of pallor or “ bull’s eye appearance “ Found in patients with hemoglobinopathy and thalassemias
Secondary to Developmental Macrocytosis Secondary to Membrane Abnormalities- Spherocyte – small, spherical or rounded shape RBC. They appear thicker than No and are hyperchromic with increase osmotic fragility.- Echinocyte – crenated RBC, small rbc with uniformly sized, blunt projections evenly distributed. Artifactual due to hypertonic solutions or excessive air drying of smears
- Burr cell – RBC with unevenly spaced spicules, more pointed rather than blunt- Acanthocyte – spur cell, RBC with club-shaped (swollen) spicules, or prominent irregular thorn-like projections- Stomatocyte – slit-shaped or mouth-like areas of pallor. On wet mounts, appear to be uniconcave or “rice-bowl” appearance
- Codocyte – target cell, codocyte, Mexican hat cell or “ bulls-eye appearance”- Ovalocyte – also called elliptocyte, rbc with cigar, oval or elliptical shapes.True ovalocytes are to be distinguished from pseudoelliptocytes where true ovalocytes arranged at random order. Pseudo follow one uniform direction usually due to poor smear preparation.
- Schistocyte or schizocyte – fragments of destroyed RBC indicating trauma or a hemolytic process- Keratocyte – RBCs with horn-like projections, also called helmit cells- Dacryocyte – teardrop looking RBCs , they appear swollen , pear-shaped- Semi-lunar bodies – pale pink, crescent shaped RBCs ( ghost cells )
- Sickle cell – depranocyte or meniscocyte sickle- shaped or crescent-shaped RBC. The abnormal Hgb S during decreased oxygen tension will crystallize or polymerize causing the cell to sickle shape- Hgb CC crystals – hexagonal shaped crystals with blunt ends- Hgb SC crystals – “ Washington monument appearance of crystals”
Developmental Organelles- Howell Jolly bodies – single blue bodies, DNA remnants. Seen in Pernicious anemia- Basophilic stipplings also known as punctuate basophilia – fine to coarse, blue to purple granules scattered homogenously in the cytoplasm. Remnants of ribosomal RNA and indicates disturbed erythropoiesis.
- Pappenheimer bodies or siderotic granules iron containing granules that appear dark-staining on Wright’s stain found lying on the periphery of the cell in groups. On Perl’s Prussian Blue stain, these bodies stained positively indicating iron content.- Cabot rings – ring-like, loop-like, figure of 8 staining reddish violet in Wright’s stain. Remnants of mitotic spindle or fragment of the nuclear membrane.
- Heinz bodies – dense, highly refractile granules representing precipitated or denatured globin associated with the unstable Hgb. Seen in patients with Glucose 6 Phosphate dehyrogenase (G6PD) deficiency- Hemoglobin H inclusions – greenish colored inclusions on BCB staining giving rise to the characteristic “golf-ball pattern”
- Malarial parasites – presence of malarial parasite stages ( ring forms, gametocytes etc.) or pigments (stipplings) either on Wright’s or Giemsa stained smears.- Babesia microtii – like malaria, it is an RBC infecting parasite though “tick-borne”. Only seen as ring forms in groups of 2 (rabbits ear) or 4 (Maltese cross appearance)