Clinical and radiological characteristics of 17 Chinese patients with pathology confirmed tumefactive demyelinating diseases: Follow-up study

• We reported 17 Chinese patients with pathology confirmed CNS IDD.
• Most cases had tumefactive onset and were initially misdiagnosed as brain tumors.
• Cortical gray matter was frequently involved on pre-biopsy MRI.
• Venular-like enhancement was relatively common.
• Most cases remained isolated and had favorable prognosis during follow-up.

Tumefactive demyelinating disease is a rare inflammatory demyelinating disease (IDD) of the central nervous system (CNS). The literature lacks a clear and consistent description of the clinical and radiological spectrum of this disorder, and few Chinese cases have been studied. Here we report 17 Chinese patients, with pathology confirmed CNS IDD, who had distinct clinical and imaging features from those in previous reports. Median age at onset was 47 years, with a female to male ratio of 1.1:1. Multifocal lesions were present in nine cases (53%) on their pre-biopsy magnetic resonance imagings (MRIs), with locations predominantly involving periventricular white matter (41%), subcortical white matter (41%), juxtacortical regions (41%), and cortical gray matter (35%). Moderate to severe perilesional edema and/or mass effect were present in 35% of cases. A variety of enhancement patterns were observed; most were heterogenous, including ring-like, patchy, venular-like, nodular, punctate, and diffuse in a decreased frequency. Perilesional restriction on diffusion-weighted images (DWI) were evident in 70% cases. Clinical course prior to biopsy was a first neurological event in 82% cases. During a median follow-up of 4.1 years, 76% of cases remained as isolated demyelinating syndrome, and 70% experienced a total or near-total recovery regardless of whether they received immunotherapy. Further studies are needed, especially concerning series with pathological confirmation and long-term follow-up information.