Tumours of the Nervous System: Brain, Spinal Cord and Peripheral Nerve Tumours

A rapid integration of tumour origin, morphology, anatomical location, neurological effects and management principles.

1. THE TOPIC IN ONE CONNECTED FLOW

Nervous-system tumours become clinically important through a combination of tumour type, biological behaviour and anatomical location. The same basic sequence links brain, spinal and peripheral nerve tumours: abnormal cell growth produces structural change, which disturbs neural function and determines the clinical presentation and management approach.

Tumour Origin
Glial cells, meninges, nerve sheath or metastatic deposits

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Growth Pattern
Circumscribed compression or infiltrative malignant growth

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Structural Effect
Compression, infiltration, edema or CSF-flow obstruction

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Neural Dysfunction
Focal deficits, seizures, raised pressure, myelopathy or nerve dysfunction

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Diagnostic Clue
Site, imaging pattern and characteristic histopathology

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Management
Maximal safe treatment while preserving neurological function

Key integration: Location modifies behaviour. A histologically benign meningioma or schwannoma can still cause major disability when it compresses the brain, spinal cord or an important nerve.

2. KEY CLINICAL CONNECTIONS

Brain Tumour Pattern

Infiltrative cerebral tumour → poorly defined margin → seizures or focal deficits.

Necrosis + microvascular proliferation → aggressive high-grade behaviour → supports glioblastoma.

Spinal Tumour Localization

Nerve-root compression → radicular pain → enlarging lesion may then compress long tracts.

Cord compression → weakness + sensory level + sphincter dysfunction → urgent neurosurgical assessment.

Peripheral Nerve Tumours

Encapsulated eccentric nerve mass → displaced fibres → schwannoma.

Nerve fibres incorporated into an unencapsulated lesion → neurofibroma; plexiform pattern strongly links with NF1.

3. AIM HIGH-YIELD INTEGRATION REVIEW

⭐ Glioblastoma: infiltrative growth + necrosis + pseudopalisading cells + vascular proliferation → rapid neurological deterioration.

Pilocytic astrocytoma: younger patient + cerebellar location + cyst with mural nodule + Rosenthal fibres → comparatively circumscribed low-grade tumour.

⭐ Medulloblastoma: cerebellar embryonal tumour → small round blue cells → CSF dissemination → possible spinal drop metastases.

Meningioma: dura-based extra-axial mass → whorls and psammoma bodies → progressive compressive neurological symptoms.

⭐ Spinal compartment matters: extradural, intradural-extramedullary or intramedullary location → predicts compression pattern and surgical approach.

Schwannoma versus neurofibroma: encapsulated eccentric growth favours schwannoma; nerve incorporation and plexiform growth favour neurofibroma.

⭐ NF1: neurofibromas + plexiform neurofibroma + café-au-lait pigmentation + optic pathway glioma → monitor for malignant peripheral nerve sheath tumour.

NF2: bilateral vestibular schwannomas + possible meningiomas/ependymomas → hearing and neurological surveillance are central to follow-up.

AIM Exam Trap: “Benign” describes biological behaviour, not clinical harmlessness. A benign nervous-system tumour may still cause severe neurological damage because of its anatomical location and compressive effect.