title: Atypical hairy cell leukemia.
abstract: The morphologic differential diagnosis of mature B-cell neoplasms with cytoplasmic projections includes splenic lymphoma with villous lymphocytes and hairy cell leukemia. Although the classification of hairy cell leukemia is not universally recognized, 3 variants have been described, namely, classic, variant, and Japanese variant, each of which has different clinical and immunophenotypic features. Classic hairy cell leukemia is virtually always CD11c(+), CD25(+), and CD103(+). Variant and Japanese variant hairy cell leukemias are usually CD11c(+), always CD25(-), and occasionally CD103(+). Each variant is characteristically CD10(-). We present a case of hairy cell leukemia with a unique immunoprofile in that the cells were CD10(+), CD25(+), and CD103(-), and we review the criteria helpful in differentiating "hairy" B-cell neoplasms. This case emphasizes the variability of hairy cell leukemia and the need to correlate all clinical and pathologic data in reaching a diagnosis.
authors.affiliation: Department of Pathology, Northwestern University Medical School, Chicago, IL, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Wu
authors.forename: H C
authors.initials: HC
authors.lastname: Kwaan
authors.forename: C L
authors.initials: CL
authors.lastname: Goolsby
mesh_terms: D000368:Aged; D015703:Antigens, CD / Q000032:analysis; D003937:Diagnosis, Differential; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D039001:Integrin alpha Chains; D007943:Leukemia, Hairy Cell / Q000276:immunology / Q000473:pathology*; D008297:Male; D015260:Neprilysin / Q000032:analysis; D015375:Receptors, Interleukin-2 / Q000032:analysis
chemical_list: D015703:Antigens, CD; D039001:Integrin alpha Chains; D015375:Receptors, Interleukin-2; C091367:alpha E integrins; D015260:Neprilysin