Tumefactive demyelinating lesion is a special type of neuro-inflammatory disease with unusual variants to be found in magnetic resonance imaging. It manifests as a solitary or multiple lesion greater than 2 cm in diameter and often clinically challenging because of its varieties of symptoms. We present a rare case of a 40-year-old male, presented with initial complaints of headache and unconsciousness. Yet, the physical examination findings showed normal results. Magnetic resonance imaging revealed a tumefactive demyelinating lesion suspected with brain neoplasm.