Tumefactive demyelination or tumefactive multiple sclerosis are defined as demyelinating lesions (~ 2 cm or greater) or lesions between 0.5 and 2 cm with possible mass effect that can be mistaken for tumor-like space occupying lesions and have a characteristic radiographic appearance. The prevalence of tumefactive demyelination is estimated to be approximately 1–2 per 1000 cases of MS although others suggest an incidence as high as 1.4% to 8%.  We reviewed our own experience of MS subjects diagnosed by MS Research Group (MSRG) physicians at UTHealth to determine the relationship between clinical outcomes (EDSS) and tumefactive demyelination lesion evolution, tumefactive demyelination lesion evolution and clinical outcomes in relation to different therapeutic agents in MS patients and the effect of changes in Gd+ enhancement on decreasing lesion size. In particular we asked if these lesions were truly benign, if treatment was necessary, if corticosteroids were the best therapy for reducing tumefactive demyelinating lesions and whether any DMT showed increasedbeneficial effects on clinical outcomes over time.

No patient increased in EDSS.  Overall, lesion regression was associated with improved EDSS.  Lesion regression was also associated with therapy versus no therapy. No specific therapy or corticosteroid infusions improved EDSS over the long term. The absence of enhancement on follow up on magnetic resonance imaging portended lesion regression.  

Tumefactive demyelination may predict a more benign overall course and is susceptible to traditional immunomodulatory treatments.