Tumefactive demyelinating lesions versus CNS neoplasms, a comparative study

•Sensorimotor deficits and ataxia were common amongst TDL.•Mild mass effect and lack of central enhancement are characteristics of TDL.•Peripheral diffusion restriction does not reliably differentiate TDL.•CNS lymphomas can closely mimic TDL. Differentiating tumefactive demyelinating lesions (TDL) from neoplasms of the central nervous system continues to be a diagnostic dilemma in many cases. Our study aimed to examine and contrast the clinical and radiological characteristics of TDL, high-grade gliomas (HGG) and primary CNS lymphoma (CNSL). This was a retrospective review of 66 patients (23 TDL, 31 HGG and 12 CNSL). Clinical and laboratory data were obtained. MRI brain at presentation were analyzed by two independent, blinded neuroradiologists. Patients with TDLs were younger and predominantly female. Sensorimotor deficits and ataxia were more common amongst TDL whereas headaches and altered mental status were associated with HGG and CNSL. Compared to HGG and CNSL, MRI characteristics supporting TDL included relatively smaller size, lack of or mild mass effect, incomplete peripheral rim enhancement, absence of central enhancement or restricted diffusion, lack of cortical involvement, and presence of remote white matter lesions on the index scan. Paradoxically, some TDLs may present atypically or radiologically mimic CNS lymphomas. Careful evaluation of clinical and radiological features helps in differentiating TDLs at first presentation from CNS neoplasms.