II. Evaluation

  1. Variants below as seen on Peripheral Smear
  2. Confirm Platelet Count
    1. Oil Immersion at 1000x Magnification
    2. Typical count: 15-20 per field
  3. Scan the slide for Platelet clumping (platelet agglutination)
    1. Associated with EDTA-activated antiplatelet antibodies
    2. Electronic undercounting (Pseudothrombocytopenia)
    3. Repeat sample in non-EDTA Anticoagulant

III. Causes: Platelet Abnormalities

  1. Megathrombocytes (platelet >2.5 microns diameter)
    1. Accelerated platelet production
    2. Compensation fro increased platelet destruction
    3. Vitamin B12 Deficiency
    4. Myeloproliferative diseases
    5. Congenital Thrombocytopenia (e.g. Bernard-Soulier Syndrome)
    6. Immune Thrombocytopenic Purpura
  2. Megakaryocyte Fragments
    1. Myelofibrosis
  3. Platelet hypogranularity
    1. Myelodysplastic Syndrome
    2. Myelofibrosis

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