Pathology Cheat Sheet
Site Changes the Diagnosis
CNS tumours for NEET-PG exams: glioblastoma pseudopalisading, meningioma psammoma, oligodendroglioma 1p19q, medulloblastoma rosettes, and brain metastases.
MedNext Academy | 3 min read
Site Changes the Diagnosis
CNS tumours for NEET-PG exams: glioblastoma pseudopalisading, meningioma psammoma, oligodendroglioma 1p19q, medulloblastoma rosettes, and brain metastases.
The classification and differentiating features of central nervous system tumours by site and morphology.
High-yield lines
- In adults most brain tumours are supratentorial, while in children most are infratentorial.
- Glioblastoma is the most common malignant primary brain tumour in adults and shows necrosis with pseudopalisading and microvascular proliferation.
- Meningioma is a benign extra-axial tumour arising from arachnoid cells with whorls and psammoma bodies.
- Oligodendroglioma shows a fried-egg appearance and a chicken-wire vascular pattern with 1p19q codeletion.
- Pilocytic astrocytoma is a common benign childhood tumour of the cerebellum with Rosenthal fibres.
- Medulloblastoma is a malignant cerebellar small round blue cell tumour of childhood with Homer-Wright rosettes.
- Ependymoma arises from ventricular lining and shows perivascular pseudorosettes.
- Schwannoma of the eighth cranial nerve is a common cerebellopontine angle tumour with Antoni A and B areas.
- Craniopharyngioma is a suprasellar tumour of children with calcification and machinery-oil cyst fluid.
- Metastasis is the most common intracranial tumour overall and is usually multiple at the grey-white junction.
- The site of a brain tumour is a strong clue to its likely diagnosis.
- GFAP immunostaining identifies tumours of astrocytic origin.
Mapped competency codes
- PA35.2
Continue into the full chapter
This summary maps to PA35-central-nervous-system.
Frequently Asked Questions
What is the most common malignant primary brain tumour in adults?
Glioblastoma, which shows pseudopalisading necrosis and microvascular proliferation and carries a poor prognosis.
What are the features of medulloblastoma?
A malignant cerebellar small round blue cell tumour of childhood that shows Homer-Wright rosettes and can seed the cerebrospinal fluid.
What distinguishes oligodendroglioma?
A fried-egg appearance with a chicken-wire capillary pattern and 1p19q codeletion, which predicts a better response to therapy.
What is the most common intracranial tumour overall?
Metastatic tumour, which is usually multiple and located at the grey-white matter junction, most often from lung and breast primaries.
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