C7T1L3 CNS Tumors

Introduction

  • Welcome and Happy New Year greetings

  • Overview of the topic of CNS tumors

  • Encouragement to ask questions during the lecture

  • Introduction of the speaker, Gino Pip Rowe, a practicing pathologist

Goals

  • List components of the brain and their locations

  • Compare intra-axial and extra-axial tumors

  • Discuss the W.H.O. grading system for CNS tumors

  • Differentiate childhood and adult tumors and their locations

  • Explore common tumors and their pathologic features

Components of the Central Nervous System (CNS)

  • Neurons: main cells of the brain found in the gray matter (cell bodies) and white matter (axons)

  • Neuroglial Cells (Glia): supporting cells in the CNS; includes astrocytes, oligodendrocytes, ependymal cells, and microglia

  • Ventricles: spaces in the brain containing cerebrospinal fluid (CSF)

  • Choroid Plexus: produces CSF

  • Meninges: protective layers covering the brain

  • Blood Vessels: supply nutrients to the brain

Neuroglial Cells

  • Astrocytes: star-shaped cells providing structural support, forming the blood-brain barrier, and regulating blood flow

  • Oligodendrocytes: myelinate axons in the CNS

  • Ependymal Cells: line the ventricles, produce and filter CSF

  • Microglial Cells: act as macrophages, removing waste and responding to injury/infection

Meninges Anatomy

  • Dura Mater: outermost layer, closely associated with skull

  • Arachnoid Mater: middle layer, with vascular supply

  • Pia Mater: inner layer tightly adhered to brain surface

Key Symptoms of Brain Tumors

  • Headache: most common symptom, often worse in the morning due to increased intracranial pressure during sleep

  • Other symptoms: nausea, vomiting, altered mental status, seizures, visual/auditory problems, papilledema, focal neurological deficits

Pediatric vs. Adult Brain Tumors

  • Pediatric Tumors: Primarily infra-axial, mainly in the posterior fossa (cerebellum/brainstem), highly curable, rare metastasis

  • Adult Tumors: Mostly super-axial (cerebral hemispheres), lower cure rates, approximately 50% are metastatic tumors

Intra-axial vs. Extra-axial Tumors

  • Intra-axial Tumors: Located within brain parenchyma (e.g., gliomas)

  • Extra-axial Tumors: Located outside brain parenchyma (e.g., meningiomas, cranial nerve tumors)

W.H.O. Grading System

  • Grade 1: Benign tumors (e.g., pilocytic astrocytoma)

  • Grade 2: Low-grade, more cellularity (e.g., diffuse astrocytoma)

  • Grade 3: Anaplastic tumors with increased mitosis (e.g., anaplastic astrocytoma)

  • Grade 4: Malignant tumors with necrosis and vascular proliferation (e.g., glioblastoma)

Types of CNS Tumors

Astrocytomas

  • Diffuse Astrocytoma (Grade 2): Increased cytoplasmic atypia in adults; mean survival >5 years

  • Anaplastic Astrocytoma (Grade 3): Increased cellularity, mitosis; mean survival 2 years

  • Glioblastoma (Grade 4): Most aggressive; approx. 50% of primary brain tumors; mean survival <1 year

Oligodendroglioma

  • Grade 2 Tumor: Mostly in middle-aged patients (30-50 years); better prognosis with 1p/19q codeletion

Ependymoma

  • Can occur in children and adults, Grade 2 tumor: Commonly found in the fourth ventricle (children) and spinal cord (adults); can cause hydrocephalus

Medulloblastoma

  • Grade 4 Tumor: Most common malignant pediatric brain tumor; located in posterior fossa; potential for hydrocephalus and drop metastases; 5-year survival 60-75%

Germinoma

  • Most common CNS germ cell tumor, found in pineal region; highly radiosensitive with 85% 10-year survival

Craniopharyngioma

  • Grade 1 Benign Tumor: Occurs in children (5-14 years) and adults (50-74 years); causes bitemporal hemianopsia

Primary CNS Lymphoma

  • Associated with HIV; aggressive B-cell type tumors with poor prognosis; characterized by angiocentric lesions

Metastatic Tumors

  • Common sources include lung and breast cancers; tend to appear at gray-white junction; often necrotic

Meningiomas

  • Extra-axial Tumor: Derives from arachnoid cap cells; accounts for 15% of primary brain tumors; mass effect symptoms

Schwannomas

  • Benign, derived from Schwann cells; associated with neurofibromatosis type 2 if bilateral

Neurofibromatosis

  • Grade 1 Tumors: Arise from peripheral nerve sheath; can undergo malignant transformation

Conclusion

  • Overview of CNS tumors, types, symptoms, and classifications

  • Reminder for further questions and discussion

  • Encouragement to utilize provided email for any future queries