Blood Smear Analysis for Malignant Cells

Indications and Diagnostic Process

The American Society of Hematology recommends a peripheral blood smear examination as part of a complete blood count (CBC) with differential and manual review to check for malignant cells in patients with suspected hematologic malignancy 1
Follow-up of known hematologic malignancy should include a peripheral blood smear examination 1, 2

If malignant cells are suspected or identified on peripheral blood smear, a bone marrow examination is typically the next step for definitive diagnosis, as recommended by the National Comprehensive Cancer Network 3, 4
Flow cytometry immunophenotyping may be performed on peripheral blood if sufficient abnormal cells are present, according to the College of American Pathologists 4, 5
Cytogenetic studies, including FISH and/or conventional karyotyping, may be indicated for patients with suspected hematologic malignancy, as suggested by the American College of Medical Genetics and Genomics 5, 2
Molecular studies may be needed for specific genetic abnormalities in patients with hematologic malignancies, as recommended by the International Society for Laboratory Hematology 3, 5

A peripheral blood smear alone may not be sufficient for definitive diagnosis of malignancy, and additional specialized testing is typically required, according to the American Society of Clinical Oncology 1, 3
For suspected leukemia, bone marrow examination remains the gold standard diagnostic test, as recommended by the National Cancer Institute 3, 4
In cases with dry tap or inability to obtain bone marrow, peripheral blood with sufficient blast cells may be used as an alternative, as suggested by the European Hematology Association 5