Oral hairy leukoplakia arising in a patient with hairy cell leukaemia: the first reported case.

Oral hairy leukoplakia (OHL) is an oral mucosal lesion that is associated with Epstein-Barr virus infection. It commonly presents as an asymptomatic, non-removable white patch on the lateral borders of the tongue in individuals who are immunocompromised. Historically, OHL was thought to be pathognomonic of HIV infection; however, it is now an established phenomenon in a range of conditions affecting immune competence. Hairy cell leukaemia (HCL) is a rare chronic B cell lymphoproliferative disease named after the distinctive cytology of the atypical cells. We report the first case of OHL arising in an individual with HCL that resolved following remission of the haematological malignancy.