Tumefactive Multiple Sclerosis Presenting with Seizures and Leptomeningeal Enhancement Mimicking Neoplasm: A Diagnostic and Therapeutic Challenge
Anusha Sanivarapu1, Tracey Nicole Webb1, Daniel Kaufman1, Yakov Isakov1
1Neurology, Zucker SOM Hofstra/Northwell at Vassar Brothers Medical Center
Objective:
To highlight diagnostic challenges of tumefactive multiple sclerosis presenting with seizures and leptomeningeal enhancement mimicking neoplasm, and emphasize the role of steroid responsiveness and CSF findings in guiding management.
Background:
Tumefactive multiple sclerosis (TMS) is a rare demyelinating variant that can mimic neoplasm or infection, particularly when associated with mass effect or atypical imaging features such as leptomeningeal enhancement.
Design/Methods:

A 49-year-old female with a history of multiple sclerosis (off disease-modifying therapy) and untreated focal seizures presented with a generalized tonic-clonic seizure. Prehospital hypoglycemia (glucose 54 mg/dL) was corrected. In the emergency department, she had recurrent seizures requiring benzodiazepines and was noted to be obtunded with vomiting and inability to follow commands. CT head revealed left parietal cortical thickening and sulcal effacement. CTA/CTV were negative. EEG demonstrated focal slowing in the left temporoparietal region. MRI brain showed diffuse left parietal and occipital leptomeningeal enhancement, proteinaceous sulcal material, and extensive T2 hyperintense white matter lesions concerning for demyelination versus neoplasm or encephalitis. CSF demonstrated elevated oligoclonal bands; spinal MRI showed non-enhancing T2 lesions. Given broad differential including malignancy and infection, neurosurgical biopsy was considered but deferred. The patient was treated with corticosteroids and levetiracetam with rapid clinical improvement. Initiation of ocrelizumab was delayed due to recurrent flares, medication nonadherence, and breakthrough seizures. The patient developed neuropsychiatric symptoms, including mood lability and behavioral changes, complicating adherence and requiring multiple readmissions. She was managed with dimethyl fumarate and extended-release levetiracetam.


Results:
N/A
Conclusions:
TMS can present with atypical features such as leptomeningeal enhancement, closely mimicking neoplasm. Recognition of steroid responsiveness and supportive CSF findings can help avoid unnecessary biopsy. Early initiation of high-efficacy therapy is critical, though adherence and neuropsychiatric comorbidities may significantly impact management.
Generative AI Usage
No, did not use generative AI in the drafting or editing in this abstract.
Disclaimer: Abstracts were not reviewed by Neurology® and do not reflect the views of Neurology® editors or staff.