Defining the course of tumefactive multiple sclerosis: A large retrospective multicentre study

Background and purpose: Tumefactive multiple sclerosis (TuMS) (i.e., MS onset presenting with tumefactive demyelinating lesions [TDLs]) is a diagnostic and therapeutic challenge. We performed a multicentre retrospective study to describe the clinical characteristics and the prognostic factors of TuMS. Methods: One hundred two TuMS patients were included in this retrospective study. Demographic, clinical, magnetic resonance imaging (MRI), laboratory data and treatment choices were collected. Results: TuMS was found to affect women more than men (female:male: 2.4), with a young adulthood onset (median age: 29.5 years, range: 11–68 years, interquartile range [IQR]: 38 years). At onset, 52% of TuMS patients presented with the involvement of more than one functional system and 24.5% of them with multiple TDLs. TDLs most frequently presented with an infiltrative MRI pattern (38.7%). Cerebrospinal fluid immunoglobulin G oligoclonal bands were often demonstrated (76.6%). In 25.3% of the cases, more than one acute-phase treatment was administered, and almost one-half of the patients (46.6%) were treated with high-efficacy treatments. After a median follow-up of 2.3 years (range: 0.1–10.7 years, IQR: 3.4 years), the median Expanded Disability Status Scale (EDSS) score was 1.5 (range: 0–7, IQR: 2). Independent risk factors for reaching an EDSS score ≥3 were a higher age at onset (odds ratio [OR]: 1.08, 95% confidence interval [CI]: 1.03–1.14, p < 0.01), a higher number of TDLs (OR: 1.67, 95% CI: 1.02–2.74, p < 0.05) and the presence of infiltrative TDLs (OR: 3.34, 95% CI: 1.18–9.5, p < 0.001) at baseline. Conclusions: The management of TuMS might be challenging because of its peculiar characteristics. Large prospective studies could help to define the clinical characteristics and the best treatment algorithms for people with TuMS.