E2119. Juvenile Pilocytic Astrocytoma: Uncommon Presentations of a Common Entity
  1. Yunus Hussain; Morristown Medical Center
  2. Enrique Vilarello; Morristown Medical Center
  3. Jose Rios; Morristown Medical Center
Juvenile pilocytic astrocytoma (JPA) are the most common CNS tumors in children, representing 15% of all brain tumors. These tumors have a predilection for certain locations and have a classic imaging appearance. However, occasional atypical imaging manifestations can be seen. Careful consideration of the patients’ demographics and lesion location are essential when considering JPA in a differential for an atypical lesion.

Educational Goals / Teaching Points
In this exhibit, we will review the typical features of JPAs, including patient demographics, location, presenting signs/symptoms, imaging features, pathology, and prognostic factors. We present several cases of JPAs which either occur in an unusual patient population, occur in an atypical location, or demonstrate abnormal imaging characteristics. We will also review characteristics of JPA described in literature that may mimic more aggressive lesions and those that may signal increased malignant potential.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
JPAs have the best survival rate of any glioma and demonstrate an indolent course, with signs and symptoms related to size, location, and any associated hydrocephalus. The classic imaging appearance of JPA is a cystic mass with an enhancing mural nodule. However, other imaging appearances have been described including necrotic masses and solid masses. The lack of significant surrounding edema is crucial in distinguishing JPA and other low-grade lesions from more aggressive lesions.

Juvenile pilocytic astrocytomas can present with varying imaging patterns and atypical features should not exclude the possibility of JPA. Patient demographics and lesion location should be considered when evaluating a lesion and can help narrow the differential.