Tumefactive multiple sclerosis: an uncommon diagnostic challenge

This case report describes a rare presentation of multiple sclerosis (MS) that was initially diagnosed as a peripheral nerve lesion in the emergency department. A 30-year-old woman presented to a chiropractic teaching clinic with a complaint of a sudden right foot drop. Magnetic resonance imaging of the brain revealed a large mass in the left parietal lobe with additional white matter lesions. The mass and smaller lesions were consistent with a rare presentation of demyelinating disease, tumefactive MS. The patient was referred to a neurologist for further evaluation and treatment. Her short-term clinical course was punctuated by recurrent myospasms and neurologic deficits. Tumefactive MS may mimic the clinical and magnetic resonance imaging characteristics of glioma or a cerebral abscess. The clinical presentation, pathophysiology, differential diagnosis, role of diagnostic imaging, and treatment options of MS are described. This case report illustrates that the timely diagnosis and optimal treatment of MS require recognition of its varied, sometimes atypical, and often nonspecific clinical and imaging manifestations.