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🌱 來自: Huppert’s Notes
Evaluation of a Peripheral Blood Smear🚧 施工中
Evaluation of a Peripheral Blood Smear
entire feathered edge first: Large things (e.g., platelet clumps, blasts) can sometimes end up on the feathered edge so look for these first so you don’t miss them.
Find the monolayer. Start at the very edge of the feathered edge with the microscope on 10x. Move back towards the body of the slide until the cells form a smooth monolayer.
• Evaluate WBCs**:**
- Normal and pathologic WBC morphologies are shown in Figure 7.3B
- Note any morphology changes (toxic changes, reactive lymphocytes) and any abnormal cell populations (e.g., blast cells, which have a large nucleus, immature chromatin, a prominent nucleolus, scant cytoplasm, and few or no cytoplasmic granules)
• Evaluate RBCs**:**
- Normal and pathologic RBC morphologies are shown in Figure 7.3C
- Evaluate the RBC size: Microcyte = small; macrocyte = large
- Evaluate the hemoglobin distribution:
• Hypochromasia = light RBCs with more central pallor. Often present with iron deficiency anemia.
• Polychromasia = darker RBCs. Often present with reticulocytosis/regeneration.
- Evaluate the RBC shape: Acanthocytes, schistocytes, spherocytes, etc.
- Evaluate for red cell inclusions:
• Nuclei: Not typically present in RBCs; presence suggests vigorous bone marrow response or myelophthisic process
• Basophilic stippling: Blue dots in the RBC; common in lead poisoning
• Howell-Jolly bodies: Blue inclusions from nuclear remnants common with splenic dysfunction
• Parasites: E.g., malaria, babesiosis
- Note red cell distribution: Agglutination, rouleaux formation
• Evaluate platelets**:**
- First check the feathered edge for platelet clumps as these will invalidate a low platelet count (i.e., pseudothrombocytopenia)
- Note the platelet size
FIGURE 7.3: Blood smear preparation and features. A) A blood smear has a thumbprint appearance. The body of the smear is the thickest part where cells are densely packed. The cells become more thinly spread until you reach the monolayer, the area where the red cells form a single layer with little space between them. It is easiet to count and view cells by looking at the monolayer. At the far edge of the smear is the feathered edge, where there are large white spaces between cells and there is a reticulated appearance. B) Normal mature white blood cell morphology. C) Normal and pathologic red blood cell morphology.