Primary Central Nervous System Lymphoma Presenting as Parkinsonism with Atypical MRI Findings and Elevated 14-3-3 Protein.

Primary central nervous system lymphoma (PCNSL) is a rare neoplasm with an incidence of 2 to 3% of all CNS malignancies. The diagnosis can be challenging, especially with atypical presentations. Movement disorders can be one of the rare presentations of PCNSL. Here, we present an unusual case of gradually progressing Parkinsonism with an elevation of cerebrospinal fluid (CSF) 14-3-3 protein and atypical imaging findings found to have PCNSL. A 76-year-old female patient presented with gait and intermittent speech difficulty. Initial workup revealed a contrast-enhancing lesion in the bilateral putamen and head of caudate without any mass effect. Her symptoms were rapidly progressed over 6 months and presented with mild dysarthria, bradykinesia, mild rigidity, and reduced left arm swinging. These features were consistent with Parkinsonism. The repeat imaging showed the progression of hyperintensities in the bilateral putamen. The patient underwent a stereotypic biopsy of the right caudate nucleus, which revealed PCNSL. She was treated with high-dose methotrexate and is currently in remission. Diagnosis of movement disorders remains clinical and rapid progression of symptoms, and atypical presentation must warrant further imaging and workup.