Neuroimaging: primary CNS lymphoma: 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.

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Radiology · Neuroimaging: primary CNS lymphoma

Sample item

An immunocompetent 65-year-old has confusion and a periventricular mass that is hyperdense on CT, shows homogeneous enhancement and marked restricted diffusion, and crosses the corpus callosum. What is the most likely diagnosis?

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

The answer and the reasoning

A. Primary CNS lymphoma

Lymphoma is densely cellular, hence hyperdense on CT, with homogeneous enhancement and low ADC in immunocompetent patients. Steroids may cause the lesion to vanish, so biopsy should precede them.

Option by option

  • A. Primary CNS lymphoma (correct)

    Correct. Hyperdense, homogeneously enhancing and restricting masses suggest lymphoma.

  • B. Abscess

    An abscess has a thin rim and central restricted diffusion without solid enhancement.

  • C. Glioblastoma with necrosis

    Glioblastoma has ring enhancement and central necrosis.

  • D. Metastasis with haemorrhage

    Haemorrhagic metastases show heterogeneity and oedema.

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 A, Primary CNS lymphoma. Lymphoma is densely cellular, hence hyperdense on CT, with homogeneous enhancement and low ADC in immunocompetent patients.

Why is "Abscess" not the answer?

An abscess has a thin rim and central restricted diffusion without solid enhancement.

Why is "Glioblastoma with necrosis" not the answer?

Glioblastoma has ring enhancement and central necrosis.

Why is "Metastasis with haemorrhage" not the answer?

Haemorrhagic metastases show heterogeneity and oedema.

What concept does this question test?

It tests Neuroimaging: primary CNS lymphoma in Radiology. Steroids may cause the lesion to vanish, so biopsy should precede them.

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: primary CNS lymphoma?

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.