section name header

Laboratory Tests and Interpretation of Results

Normal Range:

2% to 8%

Elevated in:

Viral diseases, parasites, infections, neoplasms, inflammatory bowel disease, monocytic leukemia, lymphomas, myeloma, sarcoidosis

Decreased in:

Aplastic anemia, lymphocytic leukemia, glucocorticoid administration

See Table E80 for changes in monocyte number.

TABLE E80 Changes in Monocyte Number

  • Monocytosis
  • Infections: Tuberculosis, granulomatous infection, brucellosis, subacute bacterial endocarditis
  • Connective tissue disorder
  • Recovery from myelosuppression
  • Hematologic malignancies
    • •MDS, MPD, MDS-MPD overlap, CMML
    • •Acute and chronic monocytic leukemia, myelomonocytic leukemia
    • •Hodgkin and non-Hodgkin lymphomas
  • Monocytopenia
  • Hairy cell leukemia
  • MonoMAC syndrome
  • Aplastic anemia
  • Drugs: Chemotherapy, IFN-α, glucocorticoids (transient)
  • Radiation therapy

CMML, Chronic myelomonocytic leukemia; IFN, interferon; MDS, myelodysplastic syndrome; monoMAC, monocytopenia and mycobacterium avium complex syndrome; MPD, myeloproliferative disorder.

From Hoffman R: Hematology: basic principles and practice, ed 6, Philadelphia, 2013, Saunders.