Magnetic resonance imaging (MRI) and positron emission tomography (PET). (A) T2-weighted image showing a huge multicystic mass in the right occipitoparietal area with marked surrounding edema and shift of the midline structures to the left side. (B) Each cyst wall and adjacent cortical mass was enhanced with contrast medium. (C) Fluorodeoxyglucose (FDG) PET showing high accumulation in the right occipitoparietal area. (D) Methionine (MET) PET showing high accumulation in the right occipitoparietal area. (E, F) MRI and PET findings at the time of recurrence. (E) Small enhanced mass adjacent to the cavity formed by removal of the tumor. (F) FDG-PET showing no accumulation in the mass. (G) MET-PET showing high accumulation in the mass. (H) MRI 4 years after the first operation.