Image Description
The morphology of hairy cells is best appreciated in the thin areas of a well-prepared peripheral blood smear. The hairy cells are 1.5 to 2 times the size of a small lymphocyte and have an oval or a bean-shaped nucleus with dispersed chromatin and inconspicuous nucleoli. The cells have moderate amount of flocculent, pale blue cytoplasm with hairy projections. The hairy cell morphology is difficult to appreciate in aspirate smears.
About the Disease
Hairy Cell Leukemia (HCL) is a mature B-cell neoplasm that mainly involves the blood, bone marrow, and splenic red pulp. It makes up only about 2% of all leukemias and predominantly affects middle-aged men (M:F = 4:1).The clinical features are often related to cytopenias and include recurrent infections (due to neutropenia) and weakness and fatigue (due to anemia). Monocytopenia is one of most sensitive markers of HCL. Splenomegaly is seen in 80% to 90% of cases; lymphadenopathy is uncommon. A small proportion of patients show polyclonal hypergammaglobulinemia. In about one-fourth of the patients, HCL is diagnosed incidentally.The neoplastic lymphocytes have an ill-defined, ruffled cytoplasmic border with hair-like surface projections. They express B-cell associated antigens CD19, CD20, and CD22. In addition, they are positive for CD103, CD25, and CD11c.