And while astrocytomas can be graded I through IV, juvenile pilocytic astrocytomas are only grade I because they are generally benign and slow-growing.

尽管星形细胞瘤可分为I到IV级，青少年毛细胞型星形细胞瘤只有I级，是因为它们通常为良性且生长缓慢。

Now, while medulloblastoma may be the most common malignant tumor, the most common primary pediatric tumor is a type of astrocytoma called a juvenile pilocytic astrocytoma.

尽管髓母细胞瘤可能是最常见的恶性肿瘤，最常见的儿童原发脑肿瘤是一种星形细胞瘤，称为青少年毛细胞型星形细胞瘤。

Because astrocytes are found through the brain and spinal cord, astrocytomas can form throughout those locations, but juvenile pilocytic astrocytomas are mostly infratentorial tumors in the cerebellum or near the brainstem.

因为星形细胞遍布大脑和脊髓，星形细胞瘤也可以遍布在这些部位，但青少年毛细胞星形细胞瘤大多数是位于小脑内或脑干旁的脑幕下肿瘤。