Bone tumours: bone island: practice question

A Orthopaedics 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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Orthopaedics · Bone tumours: bone island

Sample item

An incidental 7 mm round, dense, homogeneous sclerotic focus is seen in the femoral neck of a pain-free 40-year-old. Its margins radiate like thorns into the surrounding trabeculae, and a technetium bone scan shows no uptake. What is the diagnosis?

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

The answer and the reasoning

A. Bone island (enostosis)

A bone island is a benign focus of compact bone within cancellous bone, with spiculated margins blending into the trabeculae and little or no isotope uptake. It needs no treatment, though growth on follow-up or uptake should prompt a re-evaluation.

Option by option

  • A. Bone island (enostosis) (correct)

    Correct. A small, painless, spiculated dense focus that is cold on bone scan is an enostosis.

  • B. Osteoblastic metastasis

    An osteoblastic metastasis shows uptake and is usually multiple.

  • C. Osteoid osteoma

    Osteoid osteoma causes night pain, has a lucent nidus and shows intense uptake.

  • D. Low-grade osteosarcoma

    Low-grade osteosarcoma is larger, symptomatic and active on scan.

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.

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Questions about this Orthopaedics question

What is the answer to this Orthopaedics question?

The best answer is A, Bone island (enostosis). A bone island is a benign focus of compact bone within cancellous bone, with spiculated margins blending into the trabeculae and little or no isotope uptake.

Why is "Osteoblastic metastasis" not the answer?

An osteoblastic metastasis shows uptake and is usually multiple.

Why is "Osteoid osteoma" not the answer?

Osteoid osteoma causes night pain, has a lucent nidus and shows intense uptake.

Why is "Low-grade osteosarcoma" not the answer?

Low-grade osteosarcoma is larger, symptomatic and active on scan.

What concept does this question test?

It tests Bone tumours: bone island in Orthopaedics. It needs no treatment, though growth on follow-up or uptake should prompt a re-evaluation.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Bone tumours: bone island?

Pair each fracture with its classic complication and nerve injured. Then use the flashcards and the other Orthopaedics 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.