MS4A1 and Pancytopenia: However, the clinical data in association with morphological and immunophenotyping data made it possible to safely rule out diagnoses of hairy-cell leukemia (absence of pancytopenia, no cells with the classical morphology of “hairy cell” and immunophenotyping not characterized by strong expression of CD11c, CD25, CD103 and CD123 antigens) or hairy-cell leukemia variant (no lymphocytes with morphology characterized by the presence of central vesicular nucleolus, cytoplasm similar to hairy cell and absence of strong expression of CD11c and CD20 antigens).