Neuroimaging: posterior fossa tumours in children: practice question

A Radiology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

Try it

Radiology · Neuroimaging: posterior fossa tumours in children

Sample item

A 5-year-old child with morning vomiting and ataxia has a midline vermian mass that is hyperdense on non-contrast CT and shows restricted diffusion, with hydrocephalus. What is the most likely diagnosis?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. Medulloblastoma

Medulloblastoma is a densely cellular embryonal tumour, therefore hyperdense on CT and with restricted diffusion on MRI. It arises from the vermis and fills the fourth ventricle, with a tendency to seed along the CSF pathways, so spine MRI is done. Pilocytic astrocytoma is usually cystic with an enhancing mural nodule.

Option by option

  • A. Haemangioblastoma

    Haemangioblastoma occurs in adults and is a cyst with a nodule.

  • B. Ependymoma

    Ependymoma extends through the foramina of the fourth ventricle, often with calcification.

  • C. Medulloblastoma (correct)

    Correct. A hyperdense vermian mass with restricted diffusion is a medulloblastoma.

  • D. Pilocytic astrocytoma

    Pilocytic astrocytoma shows a cyst with a mural nodule and is not hyperdense.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More Radiology questions

Questions about this Radiology question

What is the answer to this Radiology question?

The best answer is C, Medulloblastoma. Medulloblastoma is a densely cellular embryonal tumour, therefore hyperdense on CT and with restricted diffusion on MRI.

Why is "Haemangioblastoma" not the answer?

Haemangioblastoma occurs in adults and is a cyst with a nodule.

Why is "Ependymoma" not the answer?

Ependymoma extends through the foramina of the fourth ventricle, often with calcification.

Why is "Pilocytic astrocytoma" not the answer?

Pilocytic astrocytoma shows a cyst with a mural nodule and is not hyperdense.

What concept does this question test?

It tests Neuroimaging: posterior fossa tumours in children in Radiology. It arises from the vermis and fills the fourth ventricle, with a tendency to seed along the CSF pathways, so spine MRI is done. Pilocytic astrocytoma is usually cystic with an enhancing mural nodule.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Neuroimaging: posterior fossa tumours in children?

Learn signs with the image, and the disease they point to. Then use the flashcards and the other Radiology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.