AIM Step 10
4th Year MBBS
Neurosciences-II
4th Year MBBS
Neurosciences-II
Student Memory Support
Tumours of the Nervous System: Brain, Spinal Cord and Peripheral Nerve Tumours
High-yield memory reinforcement for rapid KMU revision.
1. High-Yield Flashcards
Tap each question to reveal the answer.
How are nervous-system tumours broadly classified by origin?
Primary tumours arise within nervous-system structures; secondary tumours are metastases from systemic cancers.
Why can a histologically benign CNS tumour still be dangerous?
Because compression within the rigid skull or spinal canal can damage vital neural tissue.
Which microscopic features strongly support glioblastoma?
Pseudopalisading necrosis and microvascular proliferation.
Which tumour may produce a “butterfly” pattern across the cerebral hemispheres?
Glioblastoma extending through the corpus callosum.
What are the classic pathological clues of pilocytic astrocytoma?
Cyst with mural nodule, Rosenthal fibres and eosinophilic granular bodies.
Which molecular combination defines oligodendroglioma?
IDH mutation with combined 1p/19q deletion.
Which histological structure is characteristic of ependymoma?
Perivascular pseudorosettes; true ependymal rosettes may also occur.
Which embryonal brain tumour is associated with small round blue cells and Homer Wright rosettes?
Medulloblastoma.
How does medulloblastoma commonly disseminate?
Through cerebrospinal fluid, producing possible spinal “drop metastases.”
What are the hallmark microscopic features of meningioma?
Meningothelial whorls and psammoma bodies.
Where do metastatic brain tumours commonly lodge?
Near the gray-white matter junction, often with marked vasogenic edema.
What are the three main anatomical categories of spinal tumours?
Extradural, intradural-extramedullary and intramedullary.
Which spinal tumour symptoms suggest significant cord compression?
Progressive weakness, sensory level and bladder or bowel dysfunction.
Which microscopic patterns characterize schwannoma?
Antoni A and Antoni B areas with Verocay bodies.
What feature distinguishes neurofibroma from a typical schwannoma?
Neurofibroma is usually unencapsulated and incorporates nerve fibres.
What are the hallmark tumour associations of NF1 and NF2?
NF1: neurofibromas and optic pathway glioma. NF2: bilateral vestibular schwannomas with meningiomas or ependymomas.
2. Mnemonics
Mnemonic Title: Spinal Tumour Compartments
E-I-I
Meaning: Extradural → Intradural-extramedullary → Intramedullary.
Mnemonic Title: Schwannoma Histology
A-B-V
Meaning: Antoni A → Antoni B → Verocay bodies.
Mnemonic Title: NF1 Core Clinical Clues
C-F-N-L-O
Meaning: Café-au-lait macules → axillary Freckling → Neurofibromas → Lisch nodules → Optic pathway glioma.
3. Memory Tables
Schwannoma vs Neurofibroma
| Feature | Schwannoma | Neurofibroma |
|---|---|---|
| Capsule | Usually encapsulated | Usually unencapsulated |
| Relation to nerve | Eccentric; displaces fibres | Incorporates nerve fibres |
| Histology | Antoni A/B, Verocay bodies | Wavy spindle cells, myxoid stroma |
| Syndromic link | Vestibular schwannomas in NF2 | Multiple/plexiform lesions in NF1 |
NF1 vs NF2
| Feature | NF1 | NF2 |
|---|---|---|
| Protein | Neurofibromin | Merlin |
| Main tumour clue | Multiple neurofibromas | Bilateral vestibular schwannomas |
| Other clues | Café-au-lait, Lisch nodules, optic glioma | Meningiomas, ependymomas, early cataract |
| Important follow-up | Tumour change and neurological function | Hearing and neurological function |
4. Rapid Revision Points — Last-Minute Revision
Must Remember:
- Glioblastoma is infiltrative and characteristically shows necrosis with microvascular proliferation.
- Pilocytic astrocytoma commonly affects younger patients and may be cystic with a mural nodule.
- Oligodendroglioma is associated with IDH mutation and 1p/19q codeletion.
- Ependymoma characteristically shows perivascular pseudorosettes.
- Medulloblastoma is a malignant cerebellar embryonal tumour with CSF dissemination potential.
- Meningioma is typically a dura-based extra-axial tumour with whorls and psammoma bodies.
- Multiple brain metastases commonly produce marked surrounding vasogenic edema.
- Spinal tumour compartment strongly influences symptoms and surgical planning.
- Rapid painful enlargement of a plexiform neurofibroma raises concern for malignant peripheral nerve sheath tumour.
- Neurofibromatosis management centers on surveillance and treatment of symptomatic or function-threatening tumours.
Common KMU Trap: A benign nervous-system tumour may still produce severe neurological damage because anatomical compression can be clinically dangerous.
5. Clinical Memory Hooks
Rapidly progressive focal deficits + necrotic infiltrating cerebral mass
→
Think glioblastoma and aggressive infiltrative behaviour.
→
Think glioblastoma and aggressive infiltrative behaviour.
Child with cerebellar symptoms + small round blue cell tumour
→
Medulloblastoma; remember possible CSF drop metastases.
→
Medulloblastoma; remember possible CSF drop metastases.
Radicular pain followed by stiffness and weakness below a spinal lesion
→
Root compression progressing to spinal long-tract compression.
→
Root compression progressing to spinal long-tract compression.
Bilateral progressive hearing loss with vestibular schwannomas
→
Neurofibromatosis type 2.
→
Neurofibromatosis type 2.
6. Starred High-Yield Exam Points
- ⭐ Glioblastoma: pseudopalisading necrosis + microvascular proliferation.
- ⭐ Oligodendroglioma: IDH mutation + 1p/19q codeletion.
- ⭐ Medulloblastoma: malignant cerebellar embryonal tumour with CSF spread.
- ⭐ Meningioma: extra-axial dura-based mass with whorls and psammoma bodies.
- ⭐ Spinal tumour red flags: progressive weakness + sensory level + sphincter dysfunction.
- ⭐ NF1 plexiform neurofibroma with rapid enlargement or new persistent pain → suspect malignant peripheral nerve sheath tumour.