[A case of pilocytic astrocytoma in an adult].

Pilocytic astrocytoma is the most common glioma in children, in whom the majority arise in the cerebellum. In contrast, pilocytic astrocytomas are less common in adults. The most frequent locations involved are the basal ganglia, cerebellum, optic chiasm, and hypothalamus. Overall survival rates are good. The case presented involved a pilocytic astrocytoma of the right parietal lobe in a 36-year-old man. Cranial magnetic resonance imaging (MRI) revealed a small mural nodule in the wall of the cyst, with no edema around the tumor. This nodule showed a hyperintense signal on gadolinium-enhanced MRI. Computed tomography (CT) scanning revealed a hypodense right parietal lobe mass with calcification. At surgery, the cyst contents were aspirated, and the mural nodule was excised. Postoperative radiotherapy was not given. Neuropathological examination revealed a pilocytic astrocytoma (Grade I). The MIB-index was 3.3%. There has been no recurrence after 1 year of postoperative follow-up.