Systemic pathology: osteochondroma malignant change: practice question

A Pathology 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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Pathology · Systemic pathology: osteochondroma malignant change

Sample item

A 40-year-old man with multiple hereditary exostoses has had painless bony outgrowths since adolescence. One lesion near the pelvis has recently begun to enlarge and become painful. Which feature suggests malignant transformation?

AOrigin from the metaphysis of a long boneBGrowth and pain in adulthood with a thickened cartilage capCPresence of a cartilage cap on the surfaceDContinuity of the lesion cortex with the host bone

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

The answer and the reasoning

B. Growth and pain in adulthood with a thickened cartilage cap

Osteochondroma is a cartilage-capped outgrowth continuous with the medullary cavity of the host bone. Malignant change to chondrosarcoma is uncommon but more likely in multiple exostoses, and should be suspected with growth, pain or a thick cartilage cap after skeletal maturity.

Option by option

A. Origin from the metaphysis of a long bone
A metaphyseal location is typical of benign osteochondroma.
B. Growth and pain in adulthood with a thickened cartilage cap (correct)
Correct. New growth and pain after maturity with a thickened cartilage cap suggest chondrosarcoma.
C. Presence of a cartilage cap on the surface
A cartilage cap is a normal, defining feature, unless unusually thick.
D. Continuity of the lesion cortex with the host bone
Continuity with the host cortex and medulla is a normal feature of osteochondroma.

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.

Questions about this Pathology question

What is the answer to this Pathology question?

The best answer is B, Growth and pain in adulthood with a thickened cartilage cap. Osteochondroma is a cartilage-capped outgrowth continuous with the medullary cavity of the host bone.

Why is "Origin from the metaphysis of a long bone" not the answer?

A metaphyseal location is typical of benign osteochondroma.

Why is "Presence of a cartilage cap on the surface" not the answer?

A cartilage cap is a normal, defining feature, unless unusually thick.

Why is "Continuity of the lesion cortex with the host bone" not the answer?

Continuity with the host cortex and medulla is a normal feature of osteochondroma.

What concept does this question test?

It tests Systemic pathology: osteochondroma malignant change in Pathology. Malignant change to chondrosarcoma is uncommon but more likely in multiple exostoses, and should be suspected with growth, pain or a thick cartilage cap after skeletal maturity.

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 Systemic pathology: osteochondroma malignant change?

Learn each disease as a bundle: cause, key histology, markers, and the clinical hallmark. Then use the flashcards and the other Pathology 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.