From the Guidelines
Referral to a hematologist and consideration of flow cytometry is not immediately necessary for this asymptomatic patient with slightly elevated neutrophils and a history of previous normalization. Given the patient's age, 43, and the fact that the elevated white blood cell count (WBC) is not significantly high, watchful waiting with repeat complete blood counts in 1-3 months is a reasonable approach 1. The patient's previous normalization of WBC counts after a similar elevation two years ago suggests that this could be a transient or benign condition. However, it is crucial to monitor the patient's condition closely for any signs of progression or development of symptoms such as fatigue, night sweats, weight loss, or recurrent infections, which would warrant prompt referral to a hematologist. Flow cytometry would be particularly important if there are concerns for a chronic lymphoproliferative disorder, which would typically show lymphocytosis rather than neutrophilia, but this is not indicated in the current scenario. The key factor that should trigger further investigation is the persistence of elevated WBCs without a clear cause, such as infection, inflammation, medication effect, or smoking, but given the patient's asymptomatic status and previous normalization, a conservative approach is justified 1. Some important considerations in the management of elevated WBC counts include the prevention of tumor lysis syndrome and the management of hyperleukocytosis, but these are not relevant in this patient's case given the mild elevation of WBC counts. In general, the management of elevated WBC counts should be guided by the underlying cause and the presence of symptoms, and referral to a hematologist should be considered if the elevation persists or if there are concerns for an underlying hematologic disorder.
From the Research
Leukocytosis Evaluation
- An elevated white blood cell count has many potential etiologies, including malignant and nonmalignant causes 2.
- A repeat complete blood count with peripheral smear may provide helpful information, such as types and maturity of white blood cells, uniformity of white blood cells, and toxic granulations 2.
- The leukocyte differential may show eosinophilia in parasitic or allergic conditions, or it may reveal lymphocytosis in childhood viral illnesses 2.
Referral and Flow Cytometry
- If malignancy cannot be excluded or another more likely cause is not suspected, referral to a hematologist/oncologist is indicated 2.
- Flow cytometry can be used to confirm and characterize lymphoproliferative disorders, and to distinguish between reactive lymphoid proliferation and lymphoproliferative neoplasm 3.
- Flow cytometry can also be used to evaluate myeloid leukocytosis and to distinguish between myeloid leukemoid reactions and myeloid malignancies 3.
Asymptomatic Leukocytosis
- Asymptomatic leukocytosis can be caused by a variety of factors, including stress, exercise, and certain medications 4.
- Primary bone marrow disorders should be suspected in patients who present with extremely elevated white blood cell counts or concurrent abnormalities in red blood cell or platelet counts 4.
- In this case, since the patient is asymptomatic and has a slightly elevated neutrophil count, it is likely that the leukocytosis is benign, but further evaluation is needed to rule out malignancy 2, 4, 3.