MLAB 1415: Hematology RBC Morphology on a Peripheral Blood Smear

Laboratory: RBC Morphology on a Peripheral Blood Smear

Skills= 20pts

Objectives:

  1. Identify examples of abnormal red blood cell (RBC) morphology and inclusions.
  2. To determine within one qualitative unit the abnormalred blood cell morphology observed on a peripheral blood smear.

Principle:

Peripheral blood smears are evaluated to determine cell morphology, verify automated cell counts, and determine the percentage of each type of WBC. Today’s lab focuses on identifying red blood cell inclusions and abnormal RBC morphology.

Reagents, Supplies, and Equipment:

  1. Prepared slides
  2. Microscope, immersion oil and lens paper

Procedure:

  1. Place a Wright stained slide on stage.
  2. Using the 10X objective, find an area where 50% of the RBCs are slightly overlapping and 50% of the RBCs are not touching (toward the feathered edge). The red blood cells should have a central pallor. Avoid areas where holes in the blood smear are seen or the RBCs look flat, large and distorted. Also, avoid thicker areas of the smear where the RBCs appear to have rouleaux.
  3. Using the turret, switch to the 100X oil objective, add oil, and focus on the red blood cells.
  4. In at least 10 consecutive fields, observe the number of inclusions, and/or examples of abnormal RBC morphology. If abnormalities are observed, calculate the average number observed per field.
  5. Semi-quantitate any variation from normal morphology using the tables below.
  6. If no significant RBC morphology is seen, report RBC morphology as “Normal” or normochromic, normocytic.
  7. Record results on results form below.
  8. Repeat with a second slide.

Procedural notes:

RBC inclusions and morphology definitions
Variation Abnormality / Description
Anisocytosis / Variation in RBC size
Poikilocytosis / Variation in RBC shape (clarify particular variation such as 1+schistocytes, 2+ codocytes)
Abnormal Size / Description
Microcytosis / Abnormally small RBC with MCV <80fL and diameter less than 7.0 µm
Macrocytosis / Abnormally large RBC with MCV >100fL.
Abnormal Color / Description
Hypochromia / Enlarged area of pallor due to cell’s decreased hemoglobin content
Polychromasia / Bluish/purple hue in young RBCs due to residual RNA
Abnormal Shape / Description
Echinocyte or Burr Cell (Crenated RBC) / RBCs with many blunt spicules. This can be caused by biologic reasons (uremia, Vit. E deficiency abetalipoproteinemia, post-splenectomy) or artifactual (slow drying, old RBCs, in thick area of slide). Do not grade these cells in the thick area of the slide.
Drepanocyte (Sickle cell) / Elongated cell with point on each end; may be curved or S-shaped.
Schistocyte or schizocyte (cell fragment) / Fragmented erythrocyte in many shapes and sizes; can display pointed extremities
HELMET CELL (bite cell) / Special schistocyte; Results from RES taking a “bite” out of RBC. Looks like 1920s football helmet.
Codocyte (target cell) / Bull’s eye looking RBC. Central concentration of hemoglobin surrounded by colorless area with peripheral ring of hemoglobin. May also be bell or cup shaped. See atlas.
Dacryocyte (Tear drop cell) / RBC shaped like a tear or pear. Before reporting make sure that they are not artifactual due to slide preparation (all pointing same direction)
Stomatocyte / RBC with slitlike (smile) area of central pallor.
Acanthocyte (spur cell) / RBC with irregularly spaced projections that vary in width, length and number.
Elliptocyte or Ovalocyte / Ellipto: cigar-shapped RBC
Ovalo: egg-shaped RBC
Spherocyte / Small, globular, completely hemoglobinated RBC without central pallor
Inclusions / Descriptions
Hemoglobin C crystal / Dark red hexagonal RBC inclusion
Basophilic stippling / Bluish-black granules (Wright’s stain) in RBCs from precipitating ribonucleoproteins and mitochondrial remnants in toxic states (lead poisoning)
Howell-Jolly bodies / Dark purple spherical granule near periphery of RBC composed of remnants of DNA
Pappenheimer bodies / Cluster of iron-containing particles usually found at the periphery of mature RBCs
Malaria / Can appear as rings within RBC
Arrangement / Descriptions
Rouleaux / Stacked coin appearance of RBCs (in the examining area of the smear)
Agglutination / Clusters of RBCs due to presence of a cold-acting antibody against red cells
RBC Morphology Grading System/hpf (100X oil)
Abnormality / Slight / 1+ / 2+ / 3+ / 4+
Variation Abnormality / Reserved for extreme cases where 90-100% of the cells are abnormal
Reserved for extreme cases where 90-100% of the cells are abnormal
Anisocytosis / <15% / 15-25% / 26-49% / 50-89%
Poikilocytosis / If present, state “poikilocytosis present” and grade each type of abnormal shape
Abnormal Size
Microcytosis / OCC/Few / Without CBC:
25% smaller than nucleus of small lymph / Without CBC:
26-49% smaller than nucleus of small lymph / Without CBC:
≥50% smaller than nucleus of small lymph
MCV 75-79 / MCV 70-75 / MCV <70
Macrocytosis / OCC/Few / Without CBC:
25% larger than nucleus of small lymph / Without CBC:
26-49% larger than nucleus of small lymph / Without CBC:
≥50% larger than nucleus of small lymph
MCV 100-150 / MCV 105-110 / MCV >110
Abnormal Color
Hypochromia / Few / Without CBC:
25% larger area of central pallor / Without CBC:
26-49% larger area of central pallor / Without CBC:
≥50% larger area of central pallor
MCHC 28-31 / MCHC 24-27 / <24
Polychromasia / 2 / 3-4 / 5-7 / 8
Abnormal Shape
Echinocyte or Burr Cell (Crenated RBC) / <1 / 1-3 / 4-5 / >5
Codocyte (target cell) / 1-2 / 3-4 / 5-7 / ≥8
Schistocyte or schizocyte (cell fragment) / <1 / 1-3 / 4-5 / >5
Helmet cell
(bite cell) / <1 / 1-3 / 4-5 / >5
Drepanocyte (Sickle cell) / <1 / 1-3 / 4-5 / >5
Dacryocyte (Tear drop cell) / <1 / 1-3 / 4-5 / >5
Stomatocyte / <1 / 1-3 / 4-5 / >5
Acanthocyte (spur cell) / <1 / 1-3 / 4-5 / >5
Elliptocyte or Ovalocyte / 2 / 3-4 / 5-7 / >8
Spherocyte / 2 / 3-4 / 5-7 / 8
Inclusions
Hemoglobin C crystal / <1 / 1-3 / 4-5 / >5
Basophilic stippling / <1 / 1-3 / 4-5 / >5
Howell-Jolly bodies / <1 / 1-3 / 4-5 / >5
Pappenheimer bodies / <1 / 1-3 / 4-5 / >5
Arrangement
Rouleaux / 10% / 10 -25% / 25%-50% / ≥50%
Agglutination / 10% / 10 -25% / 25%-50% / ≥50%

MLAB 1415: Hematology RBC Morphology on a Peripheral Blood Smear

Name: ______
Date:______

Laboratory: RBC Morphology on a Peripheral Smear

Report Form

20 pts

Slide # or Patient Name / Abnormal variation
(aniso/ poik) / Abnormal Size / Abnormal Shapes / Inclusions/ RBC Color

MLAB 1415: Hematology RBC Morphology on a Peripheral Blood Smear

Name: ______

Date:______

Laboratory: RBC Morphology on a Peripheral Smear

Study Questions

11pts.

  1. Poikilocytosis is the term for variation in ______.
  1. Microcytes are defined as having an MCV less than ______.
  1. Howell-Jolly bodies are composed of ______.
  1. According to the ACC RBC morphology grading scheme, if an average of 7 bluish-purple young RBCs were observed in 10 100x/oil fields, what morphology abnormality would you document and how would you grade it? (2pts)
  1. According to the ACC RBC morphology grading scheme, if an average of 40% of the RBCS in 10 100x/oil fields had a significantly larger than normal central pallor, what morphology abnormality would you document, and how would you grade it? (2pts)
  1. Pappenheimer bodies are composed of ______.
  1. A schistocyte is also known as a cell ______.
  1. A sickle cell is also known as a ______.
  1. What causes agglutination on the blood smear?