Tumefactive multiple sclerosis: the lethal chameleon

Abstract

Tumefactive multiple sclerosis (TMS) is a rare variant of multiple sclerosis that presents with a large demyelinating lesion in the central nervous system, accompanied by peripheral ring-like enhancement, perilesional oedema and mass effect. We report a case of a 59-year-old woman who was admitted to the hospital with a four-day history of somnolence, muscle weakness in her left extremities and ultimately, loss of consciousness. Over the following 48 hours, the patient’s condition worsened with progressive consciousness impairment. Although the results of the initial head computed tomography (CT) scan supported the diagnosis of a multifocal ischaemic stroke, toxoplasmosis was proposed as the most credible diagnostic hypothesis by brain magnetic resonance imaging (MRI). Due to the adverse clinical progression following the initiation of targeted therapy and inconclusive investigation, a brain biopsy was performed, which was indicative of active TMS in a subacute phase. The patient was started on plasmapheresis and natalizumab along with corticosteroids, with a very good response. In conclusion, we report a biopsy-proven TMS diagnosis in a patient that clinically mimicked an acute stroke and was radiographically confounded with intracranial toxoplasmosis. It highlights that TMS is an uncommon neurological demyelinating disease that is often misdiagnosed. It also emphasises the importance of establishing an accurate differential diagnosis to promptly initiate aggressive immunosuppressive treatment, which may result in a more favourable prognosis.