Tumefactive multiple sclerosis masquerade as a central nervous system tumor: a case report

INTRODUCTION: Tumefactive multiple sclerosis is a demyelinating disorder that appears tumor-like on MRI. To most physicians, diagnosing tumefactive MS by applying clinical, radiological, or laboratory examination like Cerebrospinal fluid (CSF) analysis, can be challenging and ultimately biopsy is necessary to confirm the diagnosis. CASE PRESENTATION: This paper reports a case of a 37-year-old woman who presented with progressive headache and a strong family history of cancer and was misdiagnosed as having a CNS glioma. After considering the MRI features, CSF analysis results and observing improvement with IV steroids, the diagnosis of tumefactive MS was made. The patient refused biopsy to rule out the possibility of tumor or abscess. Nine months later, she presented with another relapse and an injectable disease modifying treatment (DMT) was initiated, and her course has been stable in follow up. TAKE-AWAY LESSON: The overall clinical importance of this case report is to highlight the real possibility of being forced to decide between Tumefactive demyelinating lesions (TDLs) and brain tumors in clinical practice, in order to avoid unnecessary biopsy.