Primary Hematopoietic and Lymphoid Tissue ›› Bone Marrow ›› Normal

Platelets*






Microscopic Features:
  • Most are 1/5 to 1/3 the size of a normal RBC
  • They are typically round with a blue-gray cytoplasm
  • Cytoplasm with purple/blue granules
Normal % blood-PB, marrow-BM, lymphoid tissue-LN:
  • PB: Many
  • BM: Scattered
  • LN: None
May Resemble:
  • Schistocyte
  • Stain precipitate
  • Malaria infection
  • Babesia infection
Differential Diagnoses:

Increased in:
Iron deficiency Anemia
Acute or chronic inflammation
Myeloproliferative Neoplasm (e.g. Essential Thrombocythemia, etc.)
Drug reaction
Exercise

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Decreased in:
Microangiopathic Hemolytic Anemias (e.g. DIC, TTP, and HUS)
Malignancy with Marrow infiltration
Drug induced
Infection (e.g. sepsis leading to DIC)
Autoimmune (e.g. ITP)
Nutritional deficiencies
Splenic sequestration
Hereditary

Classic Immunophenotype:
  • CD41+
  • CD42+
  • CD61+
Cartoon Image:



Misc:
  • Platelets are the smallest cellular fragments noted on a peripheral blood smear