Huge arachnoidal cyst with recent onset of seizure in an adult
Mohamed El Biadi1,&, Salah Bellasri1
&Corresponding author
A 68-year-old right-handed man, having consulted for the occurrence of a first epileptic seizure. Brain computerized tomography (CT) scan and magnetic resonance imaging (MRI) showed a giant congenital supratentorial arachnoidal cyst occupying the anterior two-thirds of the right hemisphere, measuring 14.09x6.07 (APxT) cm and 11.67 cm high, compressing the right cerebral hemisphere and the right cerebral peduncle with a midline shift. Arachnoidal cysts are congenital malformations containing cerebrospinal fluid. They may be asymptomatic and discovered incidentally on imaging. When they are large, as in this patient, they can cause a mass effect.
Figure 1: magnetic resonance imaging of the brain (axial T1-weighted: A) and coronal T2-weighted; B) cerebral computerizing tomography scan in spontaneous contrast, sagittal section; C) huge compressive arachnoidal cyst of the non-dominant hemisphere