Hairy cell lymphoma: a unique presentation of hairy cell leukaemia

Abstract

Very rarely, hairy cell leukaemia presents as an isolated mass (lymphomatous form) without apparent bone marrow, blood or spleen involvement. This unusual form of hairy cell leukaemia expresses the distinctive immunohistochemical and genetic hallmarks of classical hairy cell leukaemia, and is a plausible consideration in the differential diagnosis of B-cell neoplasms presenting as a mass. The effectiveness of cladribine therapy in these cases suggests that this variant is comparable to hairy cell leukaemia presenting classically.