NCI Definition: A WHO grade I, relatively circumscribed, slowly growing, often cystic astrocytoma occurring in children and young adults. Histologically it is characterized by a biphasic pattern with compacted bipolar cells associated with Rosenthal fibers and multipolar cells associated with microcysts and eosinophilic bodies/hyaline droplets. (WHO) [1]

Pilocytic astrocytomas most frequently harbor alterations in BRAF, NF1, and FGFR1 [2].

Most Commonly Altered Genes in Pilocytic Astrocytoma

NF1 Mutation and FGFR1 Mutation are the most common alterations in pilocytic astrocytoma [2].

Top Alterations in Pilocytic Astrocytoma

Biomarker-Directed Therapies

Significant Genes in Pilocytic Astrocytoma


KIAA1549 +

NF1 +

Disease Details

Grade I Astrocytic Neoplasm, ASTROCYTOMA, PILOCYTIC, BENIGN, Astrocytoma, Benign, Grade I Astrocytoma, Grade I Astrocytic Tumor
Low Grade Astrocytic Tumor
Childhood Pilocytic Astrocytoma
OncoTree Name
Pilocytic Astrocytoma
OncoTree Code


1. National Cancer Institute. NCI Thesaurus Version 18.11d. https://ncit.nci.nih.gov/ncitbrowser/ [2018-08-28]. [2018-09-21].

2. The AACR Project GENIE Consortium. AACR Project GENIE: powering precision medicine through an international consortium. Cancer Discovery. 2017;7(8):818-831. Dataset Version 6. This dataset does not represent the totality of the genetic landscape; see paper for more information.

3. All assertions and clinical trial landscape data are curated from primary sources. You can read more about the curation process here.