Hairy cell leukemia with isolated bone lesions.

Key Clinical Message: 18F-FDG PET/CT has clinical relevance in HCL at diagnosis and for the follow-up of patients treated, especially in case of atypical presentations such as bone involvements (which are probably underestimated) and poor bone marrow infiltration. Abstract: Bone lesions are rarely reported in Hairy Cell Leukemia (HCL). We report two BRAFV600E mutated HCL patients presented bone lesions at foreground, poor bone marrow involvement, and the important role 18F-FDG PET/CT played in their management. We discuss the crucial role that 18F-FDG PET/CT could play in HCL routine practice.