The unusual case of an exclusively intracranial localization of fasciitis (CF) in a man aged 47 is reported. The cystic lesion had been accidentally discovered 10 years before when the patient sustained a contralateral ischemic stroke; the cyst, being absolutely silent, was not operated on at that time. After 10 years, the patient complained of seizures and mild right-sided paresis. CT scan revealed a dramatic increase of the lesion whose mass effect caused an initial subfalcial herniation of the brain. The mass was grossly removed, the patient recovered and become seizure-free. CF, rare in childhood, is exceptional in the adult age. The importance of a correct histological diagnosis is hereby stressed, because CF is absolutely benign, self-limiting, and does not require further treatment, but may be misdiagnosed as sarcoma.