Neoplasia: alveolar rhabdomyosarcoma: 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 · Neoplasia: alveolar rhabdomyosarcoma

Sample item

A 14-year-old has a rapidly growing mass in the forearm. Biopsy shows small round blue cells in a nested pattern with fibrous septa and myogenin positivity, and a translocation fuses PAX3 with a forkhead transcription factor gene. What is the diagnosis?

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

The answer and the reasoning

B. Alveolar rhabdomyosarcoma

Alveolar rhabdomyosarcoma carries t(2;13) PAX3-FOXO1 (or t(1;13) PAX7-FOXO1), occurs in adolescents on the limbs and has a worse prognosis than the embryonal type. Ewing sarcoma carries EWSR1-FLI1 and CD99 positivity.

Option by option

  • A. Embryonal rhabdomyosarcoma

    Embryonal rhabdomyosarcoma occurs in young children and lacks this fusion.

  • B. Alveolar rhabdomyosarcoma (correct)

    Correct. PAX3-FOXO1 with myogenin positivity identifies the alveolar type.

  • C. Synovial sarcoma

    Synovial sarcoma carries t(X;18) SS18-SSX.

  • D. Ewing sarcoma

    Ewing sarcoma has t(11;22) EWSR1-FLI1 and is CD99 positive, not myogenin positive.

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, Alveolar rhabdomyosarcoma. Alveolar rhabdomyosarcoma carries t(2;13) PAX3-FOXO1 (or t(1;13) PAX7-FOXO1), occurs in adolescents on the limbs and has a worse prognosis than the embryonal type.

Why is "Embryonal rhabdomyosarcoma" not the answer?

Embryonal rhabdomyosarcoma occurs in young children and lacks this fusion.

Why is "Synovial sarcoma" not the answer?

Synovial sarcoma carries t(X;18) SS18-SSX.

Why is "Ewing sarcoma" not the answer?

Ewing sarcoma has t(11;22) EWSR1-FLI1 and is CD99 positive, not myogenin positive.

What concept does this question test?

It tests Neoplasia: alveolar rhabdomyosarcoma in Pathology. Ewing sarcoma carries EWSR1-FLI1 and CD99 positivity.

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: alveolar rhabdomyosarcoma?

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.