II. Definitions
- Leukocytosis
- White Blood Cell Count over 11,000/mm3 (non-pregnant adults)
- See White Blood Cell Count for normal White Blood Cell ranges based on age, pregnancy
- Leukemoid Reaction
- White Blood Cell Count 50,000 to 100,000/mm3
- Caused by serious infections (C. Diff, Sepsis), solid tumor, organ rejection
- Severe Leukocytosis (Hyperleukocytosis)
- White Blood Cell Count >100,000/mm3
- Associated with Leukemia or myeloproliferative disorder
- May be associated with Leukostasis (Hyperviscosity Syndrome) in AML (or CML in Blast Crisis)
III. Causes: Cell line specific causes
- See Neutrophilia (most common cause)
- See Lymphocytosis
- See Monocytosis
- See Eosinophilia (rarely causes Leukocytosis)
IV. Causes: Benign Syndromes
- Leukemoid Reaction
- WBC Count exceeds 50,000
- Cause not involving Bone Marrow
- Usually due to non-malignant cause
- Reactive Leukocytosis
- Fever
- Focal infectious signs
- Normal Platelet Count and Hemoglobin
V. Causes: Malignancy
-
Acute Leukemia
- Thrombocytopenia
- Peripheral Smear with many immature cells (blasts)
- Marrow hypercellular with >30% blast cells
- Hyperuricemia
-
Chronic Leukemia
- Normal Platelet Count and Hemoglobin
VI. Red Flags: Signs of Hematologic Malignancies or other Bone Marrow disorders
- History
- Bruising or Bleeding Diathesis
- Fatigue or weakness
- Fever >100.4 F (38 C)
- Night Sweats
- Unintentional Weight Loss
- Immunosuppression
- Exam
- Lymphadenopathy
- Bleeding, Ecchymosis, or Petechiae
- Lethargy
- Splenomegaly or Hepatomegaly
- Labs
- Anemia (reduced RBC Count or decreased Hemoglobin or Hematocrit)
- Thrombocytopenia or Thrombocytosis
- Peripheral Blood Smear abnormalities (monomorphic Lymphocytosis, immature cells)
- White Blood Cell Count >30,000/mm3 (or >20,000/mm3 after initial management)
- WBC Count >100,000/mm3 indicates urgent hematology consult
- References
VII. Evaluation: Leukocytosis
- Step 1
- Complete Blood Count with Platelets
- Confirm persistent WBC Count >11,000/mm3
- Consider known causes
- See WBC Count for normal ranges (increased in childhood, pregnancy)
- See specific WBC cell line increases (Neutrophilia, Lymphocytosis...)
- Complete Blood Count with Platelets
- Step 2: Consider malignancy
- See Red Flags for Hematologic Malignancy as above
- Malignancy suspected
- Hematology-Oncology Consultation
- Peripheral Blood Smear
- Additional tests typically ordered by hematoology
- Bone Marrow Aspiration (critical in Acute Leukemia)
- Flow cytometry, cytogenic tests, molecular tests
- Step 3: Cell Line specific approach
- Neutrophilia (Neutrophils >7000/mm3)
- See Neutrophilia for evaluation
- Lymphocytosis (Lymphocytes >4500/mm3)
- See Lymphocytosis for evaluation
- Monocytosis (Monocytes >880/mm3)
- See Monocytosis for evaluation
- Eosinophilia (Eosinophils >500/mm3)
- See Eosinophilia for evaluation
- Basophilia (Basophils >100/mm3)
- See Basophilia for causes
- Consider malignancy
- Consider allergic condition
- Neutrophilia (Neutrophils >7000/mm3)
VIII. References
- Saiki in Friedman (1991) Medical Diagnosis, p. 227
- Abramson (2000) Am Fam Physician 62(9):2053-60 [PubMed]
- Riley (2015) Am Fam Physician 92(11):1004-11 [PubMed]
Images: Related links to external sites (from Bing)
Related Studies
| Definition (NCI) | A hematology test result that indicates the presence of an increased white blood cell count and increased neutrophil precursors resembling leukemia, in a peripheral blood smear. |
| Definition (MSH) | A peripheral blood picture resembling that of leukemia or indistinguishable from it on the basis of morphologic appearance alone. (Dorland, 27th ed) |
| Concepts | Disease or Syndrome (T047) |
| MSH | D007955 |
| ICD9 | 288.62 |
| ICD10 | D72.823 |
| SnomedCT | 56478004 |
| English | Leukemoid Reaction, Leukemoid Reactions, Reactions, Leukemoid, LEUKAEMOID REACTION, LEUKEMOID REACTION, Reaction, Leukemoid, Leukemoid reactions, leukemoid reaction (diagnosis), leukemoid reaction, Reaction leukemoid, Leukemoid reaction NOS, Leukemoid Reaction [Disease/Finding], leukemoid reactions, Leukemoid reaction, Leukaemoid reaction, Leukemoid reaction (disorder), leukemoid; reaction, reaction; leukemoid, Leukemoid reaction, NOS |
| French | REACTION LEUCEMOIDE, Etat pseudoleucémique, Leucemoïde, réaction, Réaction leucémoïde |
| German | LEUKAEMOIDE REAKTION, Reaktion leukomoid, leukaemoide Reaktion, Leukämoide Reaktion |
| Dutch | reactie leukemoïd, leukemoïd; reactie, reactie; leukemoïd, leukemoïde reactie, Leukemoïde reactie, Reactie, leukemoïde |
| Japanese | 類白血病反応, ﾙｲﾊｯｹﾂﾋﾞｮｳﾊﾝﾉｳ |
| Swedish | Leukemoid reaktion |
| Czech | leukemoidní reakce, Leukemoidní reakce |
| Finnish | Leukemoidireaktio |
| Russian | LEIKEMOIDNYE REAKTSII, ЛЕЙКЕМОИДНЫЕ РЕАКЦИИ |
| Spanish | LEUCEMOIDE, REACCION, reacción leucemoide (trastorno), reacción leucemoide, Reacción leucemoide, Reacción Leucemoide |
| Portuguese | REACCAO LEUCEMOIDE, Reação Leucemoide, Reacção leucemóide |
| Polish | Reakcja białaczkopodobna |
| Hungarian | leukaemoid reakció, Leukemoid reakció |
| Norwegian | Leukemoid reaction |
| Italian | Reazione leucemoide |
Ontology: Leukocytosis (C0023518)
| Definition (MSH) | A transient increase in the number of leukocytes in a body fluid. |
| Definition (CSP) | transient increase in the number of leukocytes in a body fluid. |
| Concepts | Pathologic Function (T046) |
| MSH | D007964 |
| ICD9 | 288.60 |
| ICD10 | D72.829 |
| SnomedCT | 154832004, 191368009, 267568006, 191364006, 142918008, 111583006 |
| English | Leukocytoses, LEUKOCYTOSIS, Leukocytosis, unspecified, leukocytosis (diagnosis), leukocytosis, Leucocytosis NOS, Leukocytosis, Leukocytosis NOS, Leukocytosis [Disease/Finding], leucocytosis, leukocytoses, Leucocytosis (finding), Disorder characterized by leukocytosis, Leucocytosis, Leukocytosis (disorder), Leucocytosis, NOS, Leukocytosis, NOS |
| French | LEUCOCYTOSE, Leucocytose SAI, Leucocytose, Hyperleucocytose |
| Portuguese | LEUCOCITOSE, Leuocitose NE, Leucocitose |
| Spanish | LEUCOCITOSIS, Leucocitosis NEOM, leucocitosis (trastorno), leucocitosis, Leucocitosis |
| German | LEUKOZYTOSE, Leukozytose NNB, Leukozytose |
| Dutch | leukocytose NAO, leukocytose, Leukocytose |
| Italian | Leucocitosi NAS, Leucocitosi |
| Japanese | 白血球増加症ＮＯＳ, 白血球増加症, ﾊｯｹｯｷｭｳｿﾞｳｶｼｮｳNOS, ﾊｯｹｯｷｭｳｿﾞｳｶｼｮｳ |
| Swedish | Leukocytos |
| Czech | leukocytóza, Leukocytóza, Leukocytóza NOS |
| Finnish | Leukosytoosi |
| Russian | LEIKOTSITOZ, ЛЕЙКОЦИТОЗ |
| Croatian | Not Translated[Leukocytosis] |
| Polish | Leukocytoza |
| Hungarian | leukocytosis, Leukocytosis k.m.n. |
| Norwegian | Leukocytose, Økt mengde hvite blodceller |
