Neoplasia: keratoacanthoma: 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.

Try it

Pathology · Neoplasia: keratoacanthoma

Sample item

A 65-year-old man has a dome-shaped nodule with a central keratin-filled crater on the sun-exposed cheek. It grew to 2 cm in six weeks. Histology shows a symmetrical, well-differentiated squamous proliferation with a keratin-filled centre and lips of epithelium at the edge. What is the most likely diagnosis?

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

The answer and the reasoning

B. Keratoacanthoma

Keratoacanthoma grows rapidly over weeks, forms a crateriform nodule filled with keratin and often regresses spontaneously, but it is difficult to separate from well-differentiated squamous cell carcinoma and is usually excised. Basal cell carcinoma has a pearly rolled edge and grows slowly.

Option by option

  • A. Actinic keratosis

    Actinic keratosis is a flat scaly premalignant patch and not a rapidly growing nodule.

  • B. Keratoacanthoma (correct)

    Correct. Rapid growth with a keratin-filled crater and symmetrical squamous architecture indicates keratoacanthoma.

  • C. Basal cell carcinoma

    Basal cell carcinoma grows slowly with palisading basaloid cells and a pearly rolled edge.

  • D. Seborrhoeic keratosis

    Seborrhoeic keratosis is a stuck-on greasy plaque with horn cysts and no crater.

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 Pathology questions

Questions about this Pathology question

What is the answer to this Pathology question?

The best answer is B, Keratoacanthoma. Keratoacanthoma grows rapidly over weeks, forms a crateriform nodule filled with keratin and often regresses spontaneously, but it is difficult to separate from well-differentiated squamous cell carcinoma and is usually excised.

Why is "Actinic keratosis" not the answer?

Actinic keratosis is a flat scaly premalignant patch and not a rapidly growing nodule.

Why is "Basal cell carcinoma" not the answer?

Basal cell carcinoma grows slowly with palisading basaloid cells and a pearly rolled edge.

Why is "Seborrhoeic keratosis" not the answer?

Seborrhoeic keratosis is a stuck-on greasy plaque with horn cysts and no crater.

What concept does this question test?

It tests Neoplasia: keratoacanthoma in Pathology. Basal cell carcinoma has a pearly rolled edge and grows slowly.

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 Neoplasia: keratoacanthoma?

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.