Pathologically Proven Gadolinium-enhanced MRI Lesions in the Bilateral Corticospinal Tracts in Lymphomatosis Cerebri

A 78-year-old woman in complete remission of mass-forming primary central nervous system lymphoma (PCNSL) showed diffuse leukoencephalopathy as well as corticospinal tract lesions with intense gadolinium enhancement on magnetic resonance imaging (MRI). She died 3 months later. In line with the MRI findings, pathological examination revealed dense infiltration of atypical lymphoid cells, consistent with a diagnosis of lymphomatosis cerebri (LC)-type PCNSL. This is the first report of LC in which the corticospinal tracts demonstrated robust contrast enhancement directly corresponding to the neuropathological findings, and it is also a rare instance in which LC presented as a recurrence of typical PCNSL.