E4518. Pediatric Head Tumors and Mimics
  1. Joseph Yang; Memorial University
  2. Matthew Beniuk; Memorial University
  3. Mark Hayward; Memorial University
  4. Eugenia Khorochkov; Memorial University
  5. Angela Pickles; Memorial University
Primary brain tumors are the most common form of neoplasm in the pediatric population. As pediatric patients can often present with variable clinical symptoms with possibly limited ability to communicate, radiologists should be aware of common pediatric tumors that may be contributory. Benign and malignant tumors, as well as pseudotumors of the brain, can result in obstructive compression of the CSF circulation, which can have fatal clinical outcomes. Additionally, there are a subset of nonmalignant tumors often associated with underlying syndromes, often prospectively diagnosed based on their neurological imaging findings with constellation of other imaging findings. The purpose of this exhibit is to present an overview of pediatric primary brain tumors and masslike mimics for practicing general radiologists and trainees to promote prompt diagnosis and direct further management.

Educational Goals / Teaching Points
The goal of this exhibit is to present both common and rarer entities of primary pediatric brain tumors and their imaging features. Additionally, pseudotumor entities that can also present similarly which will be discussed. Role of CT and MRI will be demonstrated, along with additional imaging suggestions that a radiologist can recommend for lesions commonly associated with multiorgan syndromes. A few select nuclear medicine studies will also be included. Critical imaging findings that must be urgently conveyed to the ordering physician will also be demonstrated in a case-based format.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
This exhibit will be divided into three main sections including primary brain tumors, tumors associated with syndromes, and intracranial pseudotumors with findings on both CT and MRI. Common malignant tumors such as medulloblastoma, juvenile pilocystic astrocytoma, and ependymoma will be presented. Cases of spinal drop metastases from ependymoma will be included with associated acute hydrocephalus. Lesser common lesions such as ganglioglioma, DNET, and pontine glioma will also be shown subsequently. In the syndromic lesion section, tumors commonly associated with multiorgan syndromes (such as VHL and tuberous sclerosis) such as hemangioblastoma and subependymal hamartomas will be displayed. This section will also include images of associated findings such pancreatic neuroendocrine tumor associated with VHL and renal angiomyolipoma, rhabdomyoma and lymphangioleiomyomatosis of the lungs for TS. The last section will include cases of cerebellitis mimicking a tumor, multiple cavernoma and a rare case of psudocompression of medulla by the vertebral artery.

Pediatric patients present with unique set of neurological tumors that are distinct from adult counterparts. Both benign and malignant tumors, as well as pseudotumors, can have adverse clinical outcomes if not diagnosed in a timely manner. Radiologists also play an integral role in guiding further workup for syndromes that may be yet diagnosed based on intracranial tumor findings. Therefore, familiarity with these entities remains essential for both trainees and general radiologists in their daily practice.