Clinico-radiologic Features and Therapeutic Strategies in Tumefactive Demyelination: a Retrospective Analysis of 50 Consecutive Cases.

Aims: Our goal was to expand the spectrum of clinico-radiologic characteristics and the possible therapeutic choices in patients with tumefactive demyelinating lesions (TDLs). Methods: A retrospective analysis of 50 patients with at least one TDL was performed at an academic neurology center (2008–2020). Results: Our cohort comprised mostly women (33/50) with a mean age of 38 years at TDL onset. The mean follow-up time was 76 months. The mean Expanded Disability Status Scale score at TDL onset and at the latest neurological evaluation was 3.7 and 2.3, respectively. We subcategorized the patients into seven groups based mainly on the clinical/radiological findings and disease course. Group A included patients presenting with a Marburg-like TDL ( n = 4). Groups B and C comprised patients presenting with monophasic ( n = 7) and recurrent TDLs ( n = 12), respectively. Multiple sclerosis (MS) patients who subsequently developed TDL ( n = 16) during the disease course were categorized as Group D. Group E comprised patients who initially presented with TDL and subsequently developed a classical relapsing–remitting MS without further evidence of TDL ( n = 5). Groups F ( n = 2) and G ( n = 4) involved MS patients who developed TDL during drug initiation (natalizumab, fingolimod) and cessation (interferon, fingolimod), respectively. Regarding long-term treatments applied after corticosteroid administration in the acute phase, B-cell-directed therapies were shown to be highly effective especially in cases with recurrent TDLs. Cyclophosphamide was spared for more aggressive disease indicated by a poor response to corticosteroids and plasma exchange failure. Conclusion: Tumefactive central nervous system demyelination is an heterogenous disease; its stratification into distinct groups according to different phenotypes can establish more efficient treatment strategies, thus improving clinical outcomes in the future.