Major causes of leukocytosis

• Granulocytic leukocytosis (neutrophilia)

  • Bacterial infection with left shift and reactive changes, including toxic granulation, cytoplasmic vacuolization, and Dohle bodies

    • A left shift indicates that there are neutrophils in circulation that are less mature than bands

    • Toxic granulation is the appearance of coarse, purple cytoplasmic granules; this is a sign of bacterial infection

    • Cytoplasmic (toxic) vacuolization appear as holes in the cytoplasm and are very associated with bacterial sepsis

    • Dohle bodies look like little blue lakes…they are patches of dilated ER

    • If there is neutrophilia without reactive changes there is not a bacterial infection; reactive changes are very often associated with bacterial infection

  • Physiologic stress leukocytosis (NE leads to neutrophil demargination)

  • Leukemoid reaction

    • Extreme leukocytosis with immature granulocytes stimulating leukemia

    • Differential includes overwhelming infection and chronic granulocytic leukemia

  • Leukoerythroblastosis – circulating granulocyte precursors and nucleated RBCs

• Eosinophilic leukocytosis (eosinophilia)

  • Allergic d/o (including asthma and hay fever)

  • Allergic drug reactions

  • Parasitic infections

  • Skin diseases including pemphigus, eczema, and dermatitis herpetiformis

  • Eosinophilic enteropathies including eosinophilic gastritis

  • Idiopathic hypereosinophilic syndromes including Loeffler’s

  • CA of the lung, stomach, pancreas, ovaries, or uterus

  • Collagen vascular disease (e.g., SLE)

• Lymphocytosis

  • Chronic inflammation

  • Viral infections including hepatitis, CMV, and EBV (very common cause)

• Monocytosis

  • Chronic infections including TB, bacterial endocarditis, brucellosis, malaria, and rickettsiosis

  • Chronic inflammation as seen with collagen vascular diseases and inflammatory bowel disease

  • Myelodysplastic syndromes

Category: Medical Subject Notes , Pathology Notes