Prognostic factors in Tumefactive demyelinating lesions: A retrospective study.

Introduction: Demyelinating lesions occasionally present as mass-like lesions on imaging, raising concern for malignancy. The disease course of such tumefactive demyelinating lesions (TDLs) is still being defined.

Methods: We retrospectively analyzed 21 patients with new-onset neurologic symptoms and mass-like lesions on brain magnetic resonance imaging (MRI), which resulted in biopsy-proven diagnoses of demyelination. 18 patients had a median follow-up of 52 months. The clinical, radiologic and histologic features were associated with disease course.

Results: An aggressive disease course (ADC) was noted in 33% of the patients and was associated with an initial largest lesion size ≥35 mm (p = 0.0007), mass effect (p = 0.01) and perilesional edema (p = 0.01) on MRI. Age 30 years and older, at presentation (p = 0.05), as well as the absence of a prior tonsillectomy (p = 0.0128) were also associated with an ADC.

Conclusions: We identified several factors, including initial larger lesion size, mass effect and perilesional edema on MRI, presentation after 30 years of age and the absence of a prior tonsillectomy, that predict an ADC in patients presenting with TDLs. These predictors of disease course can help guide patient follow-up and stratification for intervention.