Lymphomatosis cerebri presenting with rapidly progressive parkinsonism and Holmes tremor: a case report.

Background: Lymphomatosis cerebri (LC) is a rare subtype of primary central nervous system lymphoma (PCNSL) characterized by diffuse infiltration without mass formation. LC typically presents with cognitive decline and gait disturbances; however, extrapyramidal manifestations, including Parkinsonism and Holmes tremor, are exceedingly rare. This report describes a unique case highlighting the diagnostic challenges and atypical manifestations of LC.

Case presentation: A 75-year-old man presented with rapidly progressive cognitive decline, Parkinsonism, and Holmes tremor. Brain magnetic resonance imaging (MRI) revealed diffuse T2 and FLAIR hyperintensities involving the deep white matter, basal ganglia, and midbrain, without contrast enhancement. Despite normal dopamine transporter imaging, biopsy confirmed diffuse large B-cell lymphoma, consistent with LC. The patient received whole-brain radiation therapy, resulting in mild improvement.

Conclusions: This case illustrates that LC can manifest with atypical parkinsonian syndromes, such as parkinsonism and Holmes tremor. Clinicians should consider LC in the differential diagnosis of rapidly progressive movement disorders, especially when neuroimaging reveals diffuse non-enhancing white matter lesions such as leukodystrophy and demyelinating disease. Advanced imaging modalities such as ASL-MRI may facilitate early diagnosis and biopsy targeting.