Quick Answer
CT and MRI brain-tumour image MCQs contribute 2-4 questions per NEET PG paper across radiology, pathology, and internal-medicine sections. Five patterns recur reliably:
- Meningioma — extra-axial dural-based mass, homogeneous enhancement, dural tail, hyperostosis of adjacent bone; most common benign tumour; observe if small and asymptomatic
- Glioblastoma multiforme (GBM) — intra-axial heterogeneous ring enhancement, central necrosis, vasogenic oedema, midline shift; butterfly glioma when crossing corpus callosum; WHO grade 4; Stupp protocol; median survival 15 months
- Brain metastases — multiple, ring-enhancing, at the grey-white junction, disproportionate oedema; commonest primaries — lung, breast, melanoma, renal, colon; SRS-first for oligometastases, WBRT for high burden
- Pituitary adenoma — micro (below 10 mm) vs macro (at or above 10 mm); suprasellar extension → bitemporal hemianopia; prolactinoma commonest — cabergoline; transsphenoidal for others
- Vestibular schwannoma (acoustic neuroma) — ice-cream cone shape at CP angle with widened internal auditory canal; unilateral sensorineural hearing loss + tinnitus; bilateral → NF2; observation, gamma knife, or microsurgery
Locking these 5 patterns plus a small set of additional lesions (craniopharyngioma, ependymoma, medulloblastoma, oligodendroglioma) over 1-2 weeks moves neuroradiology MCQ accuracy from 40 to 80 percent.
Why CT brain tumour image MCQs are high-yield for NEET PG
Neuroradiology contributes 3-5 image MCQs per NEET PG paper across radiology, pathology, and medicine sections. Brain tumour patterns are stereotyped and photogenic — meningioma dural tails, GBM butterfly patterns, metastasis disproportionate oedema, sellar masses, and CP-angle acoustic neuromas each have Aunt Minnie appearances that a trained eye recognises in under 15 seconds. Pair the imaging pattern with the clinical vignette (age, presenting complaint, focal deficit, visual field defect) and the answer usually falls out.
Drilling these 5 patterns plus a small library of paediatric posterior fossa tumours, sellar and parasellar lesions, and posterior circulation metastases over 1-2 weeks moves neuroradiology MCQ accuracy from 40 to 80 percent.
Foundational approach — the systematic CT brain read
Read every brain image on 5 axes
- Location — extra-axial (dural-based, on the surface) vs intra-axial (within parenchyma); supratentorial vs infratentorial; midline vs lateral; specific compartment (sellar, suprasellar, CP angle, pineal region)
- Density — hyperdense (blood, calcification, some tumours), isodense, hypodense (oedema, necrosis, cyst)
- Enhancement pattern — none, homogeneous, ring, nodular, dural tail, patchy
- Mass effect — sulcal effacement, ventricular compression, midline shift, herniation, hydrocephalus
- Associated findings — bone changes (hyperostosis, erosion, sellar expansion), calcification, haemorrhage, cystic component
Aunt Minnie triggers for brain tumours
| Finding | First-line diagnosis |
|---|
| Extra-axial dural-based mass with dural tail + homogeneous enhancement | Meningioma |
| Intra-axial ring-enhancing mass with central necrosis crossing corpus callosum | Glioblastoma (butterfly glioma) |
| Multiple ring-enhancing lesions at grey-white junction with disproportionate oedema | Metastases |
| Sellar/suprasellar mass with expanded sella + bitemporal hemianopia | Pituitary macroadenoma |
| CP angle mass with widened internal auditory canal (ice-cream cone shape) | Vestibular schwannoma |
| Bilateral CP angle masses | NF2 |
| Midline posterior fossa mass in a child with hydrocephalus | Medulloblastoma |
| 4th ventricle intraventricular mass in a child | Ependymoma |
| Suprasellar mass with calcification and cyst in a child | Craniopharyngioma |
| Cortical calcification with contrast enhancement | Oligodendroglioma |
MCQ 1: 48-year-old woman with 6 months of headache and left arm weakness — CT shows a dural-based frontal mass with hyperostosis of adjacent bone and homogeneous enhancement
Image description: [CT brain of a 48-year-old woman. Panel 1 — Non-contrast CT — a well-defined, homogeneously hyperdense extra-axial mass sits adjacent to the right frontal convexity, based broadly on the dura. The mass shows a broad dural attachment with obtuse angles to the dura (classic extra-axial sign). Adjacent frontal bone shows hyperostosis (thickened outer table). No haemorrhage or necrosis. Surrounding vasogenic oedema is mild-to-moderate. Panel 2 — Post-contrast CT — the mass shows intense, homogeneous contrast enhancement. Panel 3 — MRI T1 post-gadolinium (added for confirmation) — homogeneous enhancing mass with a prominent dural tail (thickened enhancing dura extending from the tumour edge along the falx and adjacent convexity dura). No parenchymal invasion. Panel 4 — Coronal reformat — the mass compresses the underlying frontal cortex causing sulcal effacement and mild midline shift.]
Clinical vignette: A 48-year-old female school teacher presents with 6 months of gradually worsening headache and progressive left arm weakness. She reports mild personality change noted by her husband. On examination — left upper limb power 4/5, hyperreflexia, normal sensation, no visual field defect. Fundoscopy shows early papilloedema. She has no history of head trauma, no seizures, no fever. She is postmenopausal. CT and MRI brain are performed.
Options:
- (a) Meningioma
- (b) Glioblastoma multiforme
- (c) Solitary metastasis from breast primary
- (d) Cerebral abscess
Correct answer: (a) Meningioma
Reasoning: The triad of extra-axial dural-based location, intense homogeneous enhancement, and a dural tail on MRI defines meningioma. The broad dural base, obtuse angles to the dura, hyperostosis of the adjacent frontal bone (a specific finding), and the well-defined margin all confirm the diagnosis. Meningiomas are the commonest primary benign intracranial tumour (over 30 percent of all primary brain tumours) and are more common in middle-aged women. Falcine, parasagittal, sphenoid ridge, olfactory groove, and cerebellopontine angle are the classic locations. Growth is typically slow.
GBM would be intra-axial with heterogeneous ring enhancement and central necrosis, not the homogeneous enhancement of a dural-based mass. A metastasis is usually multiple and at the grey-white junction. An abscess would show ring enhancement with restricted diffusion on MRI DWI and a fever history.
Teaching pearl — meningioma:
| Aspect | Detail |
|---|
| Age and epidemiology | Middle-aged women; over 30 percent of primary brain tumours; slow-growing benign in most cases |
| WHO grades | Grade 1 (benign, majority), grade 2 (atypical, higher recurrence), grade 3 (anaplastic malignant, rare) |
| Classic locations | Falcine, parasagittal, sphenoid ridge (wing), olfactory groove, CP angle, foramen magnum, cavernous sinus |
| CT features | Extra-axial, dural-based, homogeneously hyperdense, calcifications common, hyperostosis of adjacent bone |
| MRI features | T1 iso to hypointense, T2 iso to hyperintense, intense homogeneous enhancement, dural tail on post-gadolinium |
| Angiography | Sunburst appearance from external carotid supply (middle meningeal artery) |
| Symptoms | Often incidental; when symptomatic — headache, focal deficit, seizure, cranial nerve palsy depending on location |
| Management | Observation with serial imaging for small asymptomatic tumours; surgical resection (Simpson grades I-V based on completeness) for symptomatic or growing; radiation for residual, atypical, or unresectable |
| Prognosis | Excellent for grade 1 completely resected (10-year survival over 90 percent) |
- NEET PG tests the extra-axial location, dural tail sign, hyperostosis, homogeneous enhancement, and the middle-aged female preponderance
MCQ 2: 58-year-old man with 3 weeks of progressive right hemiparesis and confusion — MRI shows a heterogeneous ring-enhancing mass crossing the corpus callosum
Image description: [MRI brain of a 58-year-old male. Panel 1 — T1 post-gadolinium axial — a large, heterogeneous ring-enhancing mass involves the left frontal white matter and extends across the corpus callosum genu into the right frontal lobe, producing the classic butterfly glioma pattern. Central necrosis is prominent with irregular ring thickness. Extensive surrounding vasogenic oedema and mass effect with 8-millimetre midline shift to the right. Ventricles are compressed. Panel 2 — T2 FLAIR — extensive high-signal vasogenic oedema surrounds the mass and extends into deeper white matter tracts (the FLAIR abnormality often extends well beyond the enhancing rim, representing infiltrating tumour). Panel 3 — DWI — mixed restricted diffusion with hyperintense signal within the enhancing rim (cellular tumour) and central hypointensity (necrosis). Panel 4 — MR spectroscopy — elevated choline, decreased N-acetylaspartate (NAA), and lipid-lactate peak within the mass — consistent with high-grade glial neoplasm.]
Clinical vignette: A 58-year-old retired banker presents with 3 weeks of progressive right-sided weakness, expressive aphasia, and personality change. His wife reports he has become withdrawn and confused. Examination — right hemiparesis (upper more than lower, 3/5), Broca aphasia, hyperreflexia, up-going right plantar. No fever. CT with contrast performed first shows a heterogeneous ring-enhancing left frontal mass with midline shift; MRI confirms the diagnosis. Molecular workup on subsequent biopsy shows IDH-wildtype, MGMT-promoter unmethylated.
Options:
- (a) Meningioma
- (b) Glioblastoma multiforme (butterfly glioma)
- (c) Cerebral abscess
- (d) Cerebral toxoplasmosis
Correct answer: (b) Glioblastoma multiforme (butterfly glioma)
Reasoning: The intra-axial heterogeneous ring-enhancing mass with central necrosis crossing the corpus callosum (butterfly pattern), surrounding vasogenic oedema, mass effect, and MR spectroscopy features of high-grade glial neoplasm defines glioblastoma multiforme. IDH-wildtype status confirms primary GBM (as opposed to IDH-mutant secondary GBM which now falls under IDH-mutant astrocytoma grade 4 in the 2021 WHO classification). MGMT-promoter unmethylated status predicts poorer response to temozolomide.
Meningioma is extra-axial with homogeneous enhancement. An abscess would show restricted diffusion on DWI (bright central signal) and a fever/systemic infection history. Cerebral toxoplasmosis in an HIV-positive patient would show multiple ring-enhancing lesions with the eccentric target sign.
Teaching pearl — glioblastoma multiforme (GBM):
| Aspect | Detail |
|---|
| WHO grade | Grade 4 — the most aggressive glial tumour |
| Age | Peak 60-70 years; can occur younger |
| Location | Cerebral hemispheres (white matter); classically the butterfly glioma when crossing the corpus callosum |
| CT features | Heterogeneous mass, hypodense necrosis, hyperdense haemorrhage, thick irregular ring enhancement, vasogenic oedema |
| MRI features | T1 hypointense (mass) with central necrosis, T2 hyperintense with extensive FLAIR oedema, thick irregular ring enhancement, restricted diffusion at cellular rim, MR spectroscopy shows elevated choline and lipid-lactate |
| Molecular markers | IDH-wildtype (primary GBM, most common), MGMT promoter methylation (predicts temozolomide response), 1p/19q codeletion excludes GBM (identifies oligodendroglioma) |
| Standard of care (Stupp protocol) | Maximal safe surgical resection → concurrent temozolomide + fractionated radiotherapy (60 Gy over 6 weeks) → 6 monthly cycles adjuvant temozolomide |
| Adjuncts | Tumour-treating fields (Optune) added to adjuvant temozolomide improves survival by 4-5 months; bevacizumab for recurrence |
| Median survival | 15 months with maximal therapy; 3-6 months without treatment |
| Recurrence | Universal; re-resection where feasible, bevacizumab, clinical trial |
| Palliative care | Integrated from diagnosis given trajectory |
- NEET PG tests the butterfly glioma pattern, ring enhancement with central necrosis, Stupp protocol components, MGMT significance, and the poor median survival
MCQ 3: 65-year-old ex-smoker with new-onset seizure and multiple ring-enhancing brain lesions on CT
Image description: [CT and MRI brain of a 65-year-old male. Panel 1 — Non-contrast CT — multiple hypodense lesions in both cerebral hemispheres, predominantly at the grey-white matter junction. Panel 2 — Post-contrast CT — 5 discrete ring-enhancing lesions ranging from 8 to 25 millimetres in diameter, all at the grey-white junction bilaterally. Each lesion is surrounded by disproportionately large vasogenic oedema (the ratio of oedema to lesion size is markedly greater than would be expected for a primary tumour of similar size). Two lesions in the cerebellum. Mass effect with mild sulcal effacement but no midline shift. Panel 3 — MRI T1 post-gadolinium — confirms the multiple ring-enhancing lesions with additional smaller lesions not visible on CT (MRI is more sensitive). Panel 4 — Chest CT (performed the same day) — a 4-centimetre right upper lobe spiculated mass with mediastinal lymphadenopathy suggestive of a primary lung cancer.]
Clinical vignette: A 65-year-old male retired accountant, ex-smoker of 40 pack-years, presents with a new-onset generalised tonic-clonic seizure at home. He had reported 2 weeks of morning headache worse when lying down and a 6-month unintentional 5-kilogram weight loss. Examination — no focal neurological deficits, no papilloedema. CT brain and staging chest CT are performed. Biopsy of the lung mass is subsequently confirmed as non-small cell lung carcinoma (adenocarcinoma, EGFR-wildtype).
Options:
- (a) Multiple meningiomas (NF2)
- (b) Multifocal glioblastoma
- (c) Brain metastases from a lung primary
- (d) Neurocysticercosis
Correct answer: (c) Brain metastases from a lung primary
Reasoning: Multiple ring-enhancing lesions at the grey-white junction with disproportionate vasogenic oedema in an older patient with known or suspected extra-CNS malignancy is diagnostic of brain metastases. Lung cancer is the commonest primary tumour to metastasise to the brain. The grey-white junction location reflects haematogenous embolic seeding (small vessels narrow abruptly there). The disproportion between lesion size and surrounding oedema (oedema out of proportion) is the classic radiological teaching point distinguishing metastasis from primary tumour.
Multiple meningiomas would be extra-axial and dural-based. Multifocal glioblastoma is possible but less common than metastases at this age and would show more heterogeneous solid enhancement rather than uniformly small ring-enhancing lesions. Neurocysticercosis produces multiple lesions but usually shows a scolex within a cyst, is more common in endemic areas, and shows a spectrum of stages (vesicular, colloidal vesicular, granular nodular, calcified) rather than uniform ring enhancement.
Teaching pearl — brain metastases:
| Aspect | Detail |
|---|
| Frequency | 20-40 percent of cancer patients develop brain metastases; far more common than primary brain tumours |
| Common primaries | Lung (both NSCLC and SCLC — commonest), breast, melanoma (highest per-primary rate), renal cell, colorectal |
| Location | Grey-white matter junction (embolic seeding); cerebral hemispheres 80 percent, cerebellum 15 percent, brainstem 5 percent |
| CT features | Ring or nodular enhancing lesions, disproportionate vasogenic oedema, mass effect |
| MRI features | Multiple T1 hypointense to isointense lesions with contrast enhancement (MRI more sensitive than CT and often shows additional lesions), extensive FLAIR oedema |
| Symptoms | Headache (morning, positional, from raised ICP), focal deficits, seizures (10-20 percent), altered mental status |
| Steroid response | Dexamethasone reduces oedema and improves symptoms rapidly |
| Treatment — oligometastatic (1-4 lesions) | Surgical resection or stereotactic radiosurgery (SRS — gamma knife, CyberKnife) for good local control with preserved cognition |
| Treatment — multiple (over 4-10) | SRS for as many as feasible; whole brain radiotherapy reserved for high burden or leptomeningeal disease (WBRT causes cognitive decline) |
| Targeted/immune therapy | EGFR TKIs for EGFR-mutant NSCLC with brain metastases (osimertinib has CNS activity); immunotherapy for melanoma and NSCLC |
| Prognosis | Wide range (3 to over 24 months) depending on primary, systemic disease control, performance status, and RPA/GPA prognostic scores |
- NEET PG tests the grey-white junction location, disproportionate oedema sign, common primary tumours, and the shift from WBRT to SRS-first management
MCQ 4: 42-year-old woman with 8 months of amenorrhoea, galactorrhoea, and gradually worsening visual disturbance — MRI shows a sellar/suprasellar mass
Image description: [MRI pituitary of a 42-year-old woman. Panel 1 — T1 sagittal midline — a well-defined homogeneous mass fills the sella turcica and extends superiorly through the diaphragma sellae into the suprasellar cistern (macroadenoma, 18 millimetres). The sella turcica is expanded and the floor is thinned. Panel 2 — T1 coronal post-gadolinium — the mass shows homogeneous enhancement (mildly less than normal pituitary tissue on delayed imaging). The optic chiasm is compressed and displaced superiorly by the tumour. Both cavernous sinuses show no clear invasion. Panel 3 — Automated Humphrey visual field test — bilateral bitemporal hemianopia with the superior fields affected first. Panel 4 — Endocrine workup — serum prolactin 4800 ng/mL (normal below 25) confirming a prolactinoma. Other pituitary hormones — TSH, FT4, morning cortisol, IGF-1, LH, FSH, oestradiol — mildly reduced consistent with stalk-effect hyperprolactinaemia and partial hypopituitarism.]
Clinical vignette: A 42-year-old female software engineer presents with 8 months of amenorrhoea, bilateral galactorrhoea, and gradually worsening peripheral vision — she has been bumping into doorframes and misses cars entering from the sides while driving. She has gained 3 kilograms and reports fatigue. She has no history of pregnancy in the last 5 years and is not on any dopamine-antagonist medications. Examination — bitemporal hemianopia on confrontation, mild visual acuity reduction, no papilloedema. Serum prolactin 4800 ng/mL, MRI pituitary as described.
Options:
- (a) Pituitary macroadenoma (prolactinoma)
- (b) Craniopharyngioma
- (c) Meningioma of the tuberculum sellae
- (d) Rathke cleft cyst
Correct answer: (a) Pituitary macroadenoma (prolactinoma)
Reasoning: A sellar mass measuring 10 millimetres or more with suprasellar extension, homogeneous enhancement, expanded sella, compressed optic chiasm producing bitemporal hemianopia, and markedly elevated serum prolactin (above 200 ng/mL practically confirms a prolactinoma rather than stalk-effect hyperprolactinaemia from another cause) defines a prolactinoma macroadenoma. The classic bitemporal hemianopia results from compression of the crossing nasal retinal fibres in the optic chiasm as the tumour extends superiorly through the diaphragma sellae. Superior fields are affected first (inferior chiasmal fibres compressed initially).
Craniopharyngioma classically shows a suprasellar mass with cystic and solid components plus calcification (visible on CT), commonly in children and young adults. A meningioma of the tuberculum sellae would be dural-based on the anterior sellar surface with a dural tail and typically shows more homogeneous enhancement. A Rathke cleft cyst is a benign cystic sellar lesion without solid enhancing tissue.
Teaching pearl — pituitary adenoma:
| Aspect | Detail |
|---|
| Size classification | Microadenoma below 10 millimetres; macroadenoma at or above 10 millimetres |
| Hormone secretion | Prolactinoma (commonest secreting, 40 percent), GH-secreting (acromegaly), ACTH-secreting (Cushing disease), TSH-secreting (rare), non-functioning (30-40 percent, present with mass effect) |
| Presentation — hormonal excess | Prolactinoma — amenorrhoea, galactorrhoea, infertility in women; loss of libido, ED in men; Acromegaly — coarsening features, macroglossia, sweating, cardiomyopathy; Cushing — central obesity, moon face, striae, hyperglycaemia, hypertension, osteoporosis |
| Presentation — mass effect | Bitemporal hemianopia (chiasm compression, superior fields first), cranial nerve III/IV/VI/V1-V2 palsies (cavernous sinus extension), headache, hypopituitarism (compression of normal gland) |
| Diagnosis | MRI pituitary with dynamic contrast (best), hormonal panel (prolactin, TSH, FT4, cortisol, ACTH, IGF-1, LH, FSH, oestradiol/testosterone), visual field testing |
| Prolactinoma management | Dopamine agonists first-line — cabergoline (twice weekly, better tolerated) or bromocriptine (older); shrink tumour and normalise prolactin in over 80 percent without surgery |
| Other adenomas | Transsphenoidal endoscopic resection (Cushing, acromegaly, TSHoma, non-functioning); post-op medical therapy for residual (somatostatin analogues for acromegaly, ketoconazole for Cushing) |
| Radiation | Reserved for residual or recurrent tumours not amenable to further surgery |
| Post-op complications | Transient or permanent diabetes insipidus, CSF leak, meningitis, hypopituitarism requiring lifelong hormone replacement, SIADH, hyponatraemia |
| Pituitary apoplexy | Sudden haemorrhage or infarction of adenoma — thunderclap headache, visual loss, hypopituitarism, hypotension — emergency, needs steroids and often urgent surgery |
- NEET PG tests the size cutoff (10 mm), bitemporal hemianopia mechanism, prolactinoma medical management with cabergoline, transsphenoidal approach for others, and the postoperative DI risk
MCQ 5: 45-year-old man with 2 years of progressive unilateral hearing loss and tinnitus — MRI shows an ice-cream cone shaped mass at the left CP angle
Image description: [MRI brain of a 45-year-old male. Panel 1 — T1 post-gadolinium axial at the level of the internal auditory canal — a well-defined enhancing mass sits at the left cerebellopontine angle with a narrow intracanalicular component within the widened left internal auditory canal (the cone) and a broader extra-canalicular component protruding into the CP angle cistern (the ice-cream scoop) — the classic ice-cream cone appearance. Panel 2 — T2 CISS/FIESTA (high-resolution) — the mass appears T2 hypointense against the T2 hyperintense CSF background, and the trigeminal nerve, facial nerve, and cochlear/vestibular divisions of the 8th nerve are visualised in relation to the tumour. Panel 3 — High-resolution CT temporal bone — the left internal auditory canal is widened compared to the right (classic finding), no bone destruction. Panel 4 — Pure tone audiometry — unilateral left sensorineural hearing loss with high-frequency dominance. The right ear is normal.]
Clinical vignette: A 45-year-old male banker presents with 2 years of gradually progressive left-sided hearing loss and constant left-sided tinnitus (a ringing sound). Over the last 6 months he has developed intermittent left-sided facial numbness (mostly in the cheek) and mild imbalance especially when walking in the dark. No headache, no facial weakness, no diplopia. Family history is unremarkable. Examination — left sensorineural hearing loss, mild left corneal reflex reduction, no facial weakness, no cerebellar signs. He has NO cutaneous findings suggestive of NF2 (no café-au-lait spots, no cutaneous schwannomas).
Options:
- (a) Vestibular schwannoma (acoustic neuroma)
- (b) Meningioma of the CP angle
- (c) Epidermoid cyst
- (d) Metastasis to the CP angle
Correct answer: (a) Vestibular schwannoma (acoustic neuroma)
Reasoning: A well-defined enhancing mass at the cerebellopontine angle with a narrow intracanalicular component within a widened internal auditory canal and a broader extra-canalicular component (the ice-cream cone appearance), plus unilateral sensorineural hearing loss and tinnitus in middle age, defines a vestibular schwannoma. Absence of bilateral tumours and no NF2 stigmata make sporadic unilateral vestibular schwannoma the most likely diagnosis.
CP angle meningioma sits broadly on the dura, has less internal auditory canal involvement, and often shows a dural tail. Epidermoid cyst is T1 hypointense, T2 hyperintense, does not enhance, and shows restricted diffusion on DWI. Metastasis to the CP angle is rare and usually seen with disseminated malignancy.
Teaching pearl — vestibular schwannoma (acoustic neuroma):
| Aspect | Detail |
|---|
| Origin | Schwann cells of the vestibular division (usually superior vestibular nerve) of the 8th cranial nerve; WHO grade 1 benign |
| Location | Cerebellopontine angle; extends into internal auditory canal |
| Age | Middle age; sporadic cases mostly unilateral |
| Presentation | Progressive unilateral sensorineural hearing loss (high-frequency dominant), unilateral tinnitus, imbalance; large tumours cause trigeminal numbness (V), facial weakness (VII, uncommon until late), cerebellar signs, brainstem compression, hydrocephalus |
| Imaging | MRI is gold standard — T1 iso to hypointense, T2 hyperintense, strongly enhancing after gadolinium, ice-cream cone shape; high-resolution CT temporal bone shows widened internal auditory canal |
| Audiology | Unilateral sensorineural hearing loss on pure tone audiometry; asymmetric ABR (auditory brainstem response) |
| NF2 association | Bilateral vestibular schwannomas are pathognomonic of NF2 — autosomal dominant, NF2 gene mutations on 22q12, merlin protein; also multiple meningiomas, ependymomas, other CNS schwannomas |
| Management options | Observation with serial MRI for small asymptomatic tumours; stereotactic radiosurgery (gamma knife, CyberKnife — for tumours below 3 centimetres with good tumour control and hearing preservation); microsurgical resection (translabyrinthine — no hearing preservation, best facial nerve access; retrosigmoid — hearing preservation possible; middle fossa — small intracanalicular tumours with hearing preservation) |
| Prognosis | Excellent with modern management; facial nerve preservation approaches 90 percent in specialised centres |
- NEET PG tests the ice-cream cone shape, CP angle location, unilateral sensorineural hearing loss, NF2 bilateral association, and the three management options (observation, SRS, microsurgery)
Common pitfalls in brain tumour image MCQs
Pitfall 1 — Missing the extra-axial vs intra-axial distinction
Extra-axial masses (meningioma) sit on the dura with obtuse angles, produce hyperostosis, and have dural tails. Intra-axial masses (glioma, metastasis) sit within brain parenchyma with acute angles to the surface and infiltrate white matter. This distinction is the single most important first step in reading any brain tumour image.
Pitfall 2 — Not recognising the butterfly glioma pattern
A mass crossing the corpus callosum from one hemisphere to the other in a bat-wing or butterfly configuration is almost always high-grade glioma (GBM), less commonly primary CNS lymphoma. This pattern is unique to infiltrative midline tumours.
Pitfall 3 — Missing the disproportionate oedema of metastases
Metastases classically show ring enhancement with vasogenic oedema much larger than the enhancing lesion. A primary glioma tends to have oedema more proportionate to the tumour size. When multiple lesions with disproportionate oedema appear in an older patient, think metastases and screen for a primary.
Pitfall 4 — Confusing pituitary microadenoma with normal gland variation
Small hypoenhancing regions within a pituitary of normal size on dynamic contrast MRI can represent microadenomas — but a similar appearance can occur in normal glands. Correlate with hormonal excess (prolactin, IGF-1, ACTH/cortisol) before diagnosing a microadenoma on imaging alone.
Pitfall 5 — Forgetting to consider NF2 in bilateral CP angle tumours
Bilateral vestibular schwannomas are pathognomonic of NF2. Any bilateral CP-angle enhancing mass in a young patient should prompt NF2 genetic testing and screening for other CNS tumours (meningiomas, ependymomas, other schwannomas).
How to study brain tumour radiology for NEET PG
- Master the extra-axial vs intra-axial distinction — the first step in every brain tumour image
- Learn the 5 Aunt Minnie patterns — meningioma dural tail, GBM butterfly, metastasis disproportionate oedema, pituitary macroadenoma with bitemporal hemianopia, CP-angle ice-cream cone
- Learn the WHO 2021 CNS classification updates — IDH-mutant vs wildtype astrocytoma, 1p/19q codeleted oligodendroglioma, MGMT methylation
- Learn the Stupp protocol — surgery + concurrent temozolomide/radiotherapy + adjuvant temozolomide
- Learn the visual field defects — bitemporal hemianopia from pituitary macroadenoma, homonymous hemianopia from occipital lesions
- Learn the CP angle differential — vestibular schwannoma vs meningioma vs epidermoid vs metastasis
- Learn the paediatric posterior fossa tumours — medulloblastoma, ependymoma, pilocytic astrocytoma, brainstem glioma
- Learn the sellar/parasellar differential — pituitary adenoma, craniopharyngioma, meningioma, Rathke cleft cyst, germinoma
- Practice 10 brain tumour MCQs per day for 2-3 weeks using NEETPGAI radiology bank
- Pair every image with a clinical vignette — age, presenting complaint, focal deficit, visual field defect, hormonal features
Key takeaways
- Brain tumour image MCQs contribute 2-4 questions per NEET PG paper
- Meningioma — extra-axial, dural-based, dural tail, hyperostosis; observe if small; surgical resection if symptomatic
- Glioblastoma multiforme — intra-axial ring enhancement with central necrosis; butterfly pattern when crossing corpus callosum; Stupp protocol; median survival 15 months
- Brain metastases — multiple, grey-white junction, disproportionate oedema; commonest primaries lung, breast, melanoma, renal, colon; SRS-first for oligometastases
- Pituitary macroadenoma — bitemporal hemianopia; prolactinoma treated with cabergoline; others with transsphenoidal resection
- Vestibular schwannoma — ice-cream cone at CP angle with widened internal auditory canal; unilateral sensorineural hearing loss; NF2 if bilateral
- The extra-axial vs intra-axial distinction is the single most important first step in every brain tumour image
- Molecular markers (IDH, MGMT, 1p/19q) increasingly guide brain tumour treatment and prognosis
Frequently asked questions
What are the classic CT features that distinguish meningioma from glioblastoma multiforme and from a solitary metastasis?
Three CT features separate meningioma, glioblastoma, and metastasis cleanly on NEET PG image MCQs. Meningioma is an extra-axial dural-based mass — the tumour sits on the dura rather than within brain parenchyma, produces a broad dural base on adjacent bone, causes an obtuse angle with the dura on CT, shows intense homogeneous contrast enhancement, and typically displays a dural tail (thickened enhancing dura extending from the tumour edge) on post-contrast MRI. Hyperostosis of the adjacent bone is a specific finding especially with sphenoid ridge and en plaque meningiomas. Common locations include falcine, parasagittal, sphenoid ridge, olfactory groove, and cerebellopontine angle. Glioblastoma multiforme (GBM, WHO grade 4 glial tumour) is an intra-axial parenchymal mass with heterogeneous ring enhancement, central necrosis, surrounding vasogenic oedema, and mass effect with midline shift; when the tumour crosses the corpus callosum it produces the pathognomonic butterfly glioma pattern. GBM has a very poor prognosis (median survival 15 months even with maximal surgery plus temozolomide and radiotherapy). Metastases are usually multiple, sited at the grey-white matter junction (embolic seeding), show ring enhancement with disproportionate vasogenic oedema relative to lesion size (oedema out of proportion is the classic teaching point), and the commonest primary tumours are lung, breast, melanoma, renal cell, and colon; a solitary metastasis can be indistinguishable from a primary tumour and mandates a full-body workup. NEET PG frequently tests the extra-axial vs intra-axial distinction, the dural tail sign, the butterfly pattern of GBM, and the disproportionate oedema of metastases.
How does a pituitary macroadenoma present and what are the specific visual field defects it produces?
Pituitary adenomas are classified by size — microadenoma below 10 millimetres and macroadenoma at or above 10 millimetres. Microadenomas typically present with hormonal syndromes (Cushing disease from ACTH excess, acromegaly from GH excess, galactorrhoea and amenorrhoea from prolactinoma, secondary hyperthyroidism from TSHoma) or as incidental findings. Macroadenomas present with a combination of hormonal excess (if secreting) or hypopituitarism (from compression of normal pituitary tissue), local mass effect (headache, cranial nerve palsies especially of nerves III, IV, VI, and the first two divisions of the trigeminal from lateral extension into the cavernous sinus), and visual field defects from suprasellar extension. The classic visual field defect is bitemporal hemianopia — the optic chiasm sits directly above the pituitary and the crossing nasal retinal fibres carrying temporal visual field information are compressed by upward extension of the tumour. Superior bitemporal quadrantanopia appears first because the inferior chiasmal fibres are compressed initially. Progressive compression causes complete bitemporal hemianopia and eventual optic atrophy with reduced visual acuity. On CT the sella turcica is expanded and eroded; MRI is the modality of choice showing a well-defined enhancing mass extending superiorly through the diaphragma sellae. Prolactinoma is the commonest hormone-secreting adenoma and responds to dopamine agonists (cabergoline first-line, bromocriptine older alternative) — medical therapy shrinks the tumour and normalises prolactin without surgery in most cases. Non-functioning macroadenomas and other secreting adenomas (except prolactinoma) are treated with transsphenoidal endoscopic resection. Post-op complications include diabetes insipidus (transient in most cases, permanent in some), cerebrospinal fluid leak, meningitis, and hypopituitarism requiring lifelong hormone replacement. NEET PG tests the size cutoff, bitemporal hemianopia mechanism, prolactinoma medical management, and transsphenoidal approach.
How do you recognise a vestibular schwannoma (acoustic neuroma) on imaging and what is the association with neurofibromatosis type 2?
Vestibular schwannoma (misnomer acoustic neuroma) is a benign WHO grade 1 tumour arising from the Schwann cells of the vestibular division of the 8th cranial nerve. Almost all sporadic cases are unilateral and present in middle age with unilateral sensorineural hearing loss (progressive, high-frequency dominant), tinnitus, and imbalance. As the tumour enlarges it fills the internal auditory canal and extends into the cerebellopontine angle producing an ice-cream cone shape on axial MRI (the wide extra-canalicular component is the ice-cream scoop and the narrow intracanalicular component is the cone), widens the internal auditory canal (visible on high-resolution CT temporal bone), and eventually compresses the trigeminal nerve (facial numbness), the facial nerve (facial weakness, though the facial nerve is often preserved until late), and the brainstem (ataxia, hydrocephalus). MRI shows a well-defined mass at the CP angle, T1 hypointense to isointense, T2 hyperintense, and strongly enhancing after gadolinium. The main differential is meningioma of the CP angle, which sits on the dura with a broader dural base, has less internal auditory canal involvement, and may show a dural tail. Bilateral vestibular schwannomas are pathognomonic of neurofibromatosis type 2 (NF2) — an autosomal dominant disorder caused by NF2 gene mutations on chromosome 22q12 encoding the merlin protein; bilateral schwannomas plus other CNS schwannomas, meningiomas, and ependymomas are typical. Management options include observation for small asymptomatic tumours (many grow slowly), stereotactic radiosurgery (gamma knife or CyberKnife for tumours below 3 centimetres with good tumour control and hearing preservation in selected cases), and microsurgical resection (translabyrinthine, retrosigmoid, or middle fossa approaches — chosen based on tumour size, hearing status, and facial nerve preservation goals). NEET PG tests the ice-cream cone shape, CP angle location, unilateral sensorineural hearing loss presentation, NF2 association with bilateral tumours, and the choice between observation, radiosurgery, and microsurgery.
What is the current standard of care for glioblastoma multiforme and why is prognosis so poor despite treatment?
Glioblastoma multiforme (GBM, WHO grade 4 astrocytoma) is the commonest and most aggressive primary brain tumour in adults with median survival of approximately 15 months despite maximal therapy. The current standard of care is the Stupp protocol — maximal safe surgical resection followed by concurrent temozolomide (an oral alkylating agent) plus fractionated external beam radiotherapy (60 Gy in 30 fractions over 6 weeks), followed by 6 monthly cycles of adjuvant temozolomide. Tumour-treating fields (Optune device delivering low-intensity alternating electric fields to the scalp) added to adjuvant temozolomide improves survival by 4-5 months in randomised trials and is now approved but expensive and not universally available in India. Molecular markers guide prognosis and treatment intensity — MGMT promoter methylation predicts better response to temozolomide (unmethylated tumours respond poorly); IDH1 mutation predicts a distinct secondary glioblastoma with slightly better prognosis (though IDH-mutant glioblastoma has been reclassified in the 2021 WHO classification as an IDH-mutant astrocytoma grade 4, not a true GBM); 1p/19q codeletion identifies oligodendroglioma rather than GBM. Prognosis is poor for several biological reasons — the tumour is highly infiltrative with malignant cells extending far beyond the visible enhancing rim (why complete resection is essentially impossible without removing eloquent brain), the blood-brain barrier limits drug penetration, tumour cells rapidly develop temozolomide resistance, the tumour has extensive intratumoural heterogeneity limiting single-target therapies, and the tumour recruits an immunosuppressive microenvironment that has resisted checkpoint inhibitors so far. Recurrence is universal and is treated with re-resection where feasible, bevacizumab (anti-VEGF), or clinical trial enrolment. Palliative care integration from diagnosis is standard given the trajectory. NEET PG tests the Stupp protocol components, temozolomide plus radiation timing, MGMT methylation significance, and the biological reasons for poor prognosis.
How do brain metastases present and what is the modern approach — whole brain radiotherapy vs stereotactic radiosurgery vs surgery?
Brain metastases are far more common than primary brain tumours; approximately 20-40 percent of cancer patients develop brain metastases during their disease course. The commonest primaries are lung cancer (both non-small cell and small cell), breast cancer, melanoma, renal cell carcinoma, and colorectal cancer; less commonly gastric, ovarian, prostate. Metastases seed haematogenously and preferentially lodge at the grey-white matter junction (small vessels narrow abruptly there), most often in the cerebral hemispheres (80 percent), then cerebellum (15 percent), then brainstem (5 percent). Presentation is with headache (often morning, worse with recumbency, from raised intracranial pressure), focal neurological deficits (weakness, aphasia, visual field defects depending on location), seizures (10-20 percent), and altered mental status. Imaging shows ring-enhancing lesions at the grey-white junction with disproportionate vasogenic oedema relative to lesion size (the disproportion is the classic teaching point compared with primary tumours). MRI with gadolinium is more sensitive than CT and often reveals additional smaller lesions not visible on CT. Modern management is tailored to number of lesions, size, location, primary tumour biology, patient performance status, and systemic disease burden. Steroids (dexamethasone) reduce oedema and improve symptoms rapidly. For a solitary or oligometastatic lesion (1-4 metastases) in a patient with controlled or absent systemic disease, surgical resection (if surgically accessible) or stereotactic radiosurgery (gamma knife or CyberKnife delivering a single high dose or hypofractionated regimen focused on the lesion with sharp fall-off outside) offers excellent local control and preserved cognition. For multiple metastases (over 4-10) or diffuse involvement, whole brain radiotherapy (WBRT) was historically standard but has fallen out of favour due to cognitive decline; the trend now is stereotactic radiosurgery for as many lesions as feasible, WBRT reserved for high burden or leptomeningeal disease. Immunotherapy (immune checkpoint inhibitors for melanoma and NSCLC) and targeted therapy (EGFR inhibitors for EGFR-mutant NSCLC, HER2-directed therapy for HER2-positive breast) have CNS activity in specific settings. Prognosis varies widely by primary and treatment response — median survival from brain metastasis diagnosis ranges from 3 months (poor prognosis groups) to over 24 months (favourable biology plus targeted therapy). NEET PG tests the grey-white junction location, disproportionate oedema sign, common primary tumours, and the shift from WBRT to SRS-first management.
This content is for educational purposes for NEET PG exam preparation. It is not a substitute for professional medical advice, diagnosis, or treatment. Clinical information has been reviewed by qualified medical professionals.
Written by: NEETPGAI Editorial Team
Reviewed by: Pending SME Review
Last reviewed: September 2026
