Diagnostic Approach to Leukopenia

Bone Marrow Evaluation and Specialized Testing

• Bone marrow aspiration and biopsy are indicated for persistent unexplained leukopenia, especially when accompanied by other cytopenias, and should include morphologic evaluation, cytochemical studies, conventional cytogenetic analysis, flow cytometry immunophenotyping, and molecular genetic testing 1
• Flow cytometry immunophenotyping should include markers sufficient to distinguish between various hematologic malignancies, as recommended by the American Society of Clinical Oncology 1, 2
• Molecular genetic testing should be guided by clinical suspicion and initial findings, with a focus on identifying specific hematologic disorders 3
• Cytogenetic analysis can identify chromosomal abnormalities that may indicate specific hematologic disorders, such as those associated with leukemia or lymphoma 4
• The American Society of Hematology recommends considering testing for infectious causes of leukopenia, including viral studies, and coagulation studies including prothrombin time, partial thromboplastin time, and fibrinogen 2
• In cases with suspected malignancy, additional tests such as serum lactate dehydrogenase and uric acid levels should be obtained, as recommended by the National Comprehensive Cancer Network 2

Sample Handling and Storage

• The College of American Pathologists recommends storing samples appropriately for potential future molecular or genetic studies, to ensure that diagnostic opportunities are not missed 1