Hyalinized vessel with multiplel lumina in a case of pilocytic astrocytoma. Pilocytic astrocytoma is considered to be a benign neoplasm (WHO Grade 1). The primary modality of treatment is surgery. Some cases produce significant morbidity or mortality due to their location (e.g. hypothalamus) and may not be completely resectable. Subtotally resected cases are further treated with radiation and/or chemotherapy. There is a pilomyxoid variant that is more aggressive and prone to local recurrence and spread via cerebrospinal fluid.