Non‐nodal mantle cell lymphoma mimicking hairy cell leukemia

Key Clinical Message This case of non‐nodal mantle cell lymphoma (MCL) showcases atypical hairy cell‐like features, distinguishing it via next‐generation sequencing. Despite a TP53 mutation indicating poor prognosis, our case followed an indolent course, highlighting the importance of genetic testing and phenotypical examination in MCL.