Blood/Blood Cells and Cellular Components ›› Lymphocytes ›› Abnormal
Hairy Cell Leukemia
›Microscopic Features:
- Peripheral blood smear shows lymphocytes with hair-like cytoplasmic projections
- Abnormal lymphocytes with hair-like projections are intermediate in size
- Lacks a nucleolus
- The neoplastic cells typically involve the Red Pulp area of the Spleen (as opposed to splenic Marginal zone lymphoma which involves the White pulp)
›Normal % blood-PB, marrow-BM, lymphoid tissue-LN:
- PB: None
- BM: None
- LN: None
›May Resemble:
›Differential Diagnoses:
Splenic Marginal Zone Lymphoma
Reactive Lymphocytosis
CLL
Reactive Lymphocytosis
CLL
›Classic Immunophenotype:
- CD19+
- CD20+
- CD5-
- CD10-
- CD103+
- CD11c+
- CD25+
- Annexin1+
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›Misc:
Many cases present with splenomegaly, cytopenia or pancytopenia (many with monocytopenia), and a dry bone marrow aspirate.