[Malignant or benign hyperleukocytosis ?]

Area of Science:

• Hematology
• Oncology
• Clinical Pathology

Background:

• Leukocytosis, an elevated white blood cell count, is a common finding requiring prompt differentiation between benign and malignant causes.
• Accurate diagnosis is essential for appropriate patient management and treatment strategies.

Purpose of the Study:

• To outline the diagnostic approach for evaluating leukocytosis.
• To differentiate between various causes of elevated white blood cell counts, including leukemias, lymphoproliferative disorders, myeloproliferative disorders, and benign leukemoid reactions.

Main Methods:

• Initial assessment involves a complete blood count (CBC) with differential.
• Identification of abnormal cells (e.g., blast cells, lymphoma cells, myeloid precursors) guides further investigation.
• Flow cytometry is used to determine lymphocytic phenotypes and identify clonal populations.

Main Results:

• The presence of blast cells strongly suggests leukemia, necessitating medullogram analysis.
• Lymphoma cells indicate a lymphoproliferative disorder, while myeloid precursors point to a myeloproliferative disorder.
• Monomorphic lymphocytes with a specific phenotype suggest malignancy, whereas pleomorphic lymphocytosis may indicate reactive causes like viral infections or autoimmune diseases.

Conclusions:

• A systematic approach to leukocytosis evaluation, starting with blood cell analysis, is critical for accurate diagnosis.
• Distinguishing between reactive and neoplastic processes is key, utilizing morphological and immunophenotypic characteristics.
• Exclusion of benign leukemoid reactions is an important step in the diagnostic workup.