Neoplasia: tuberous sclerosis pathway: 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: tuberous sclerosis pathway

Sample item

A child with seizures, ash-leaf macules and facial angiofibromas has a cardiac rhabdomyoma and renal angiomyolipomas. Mutations in TSC1 or TSC2 lead to excessive activity of which pathway?

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

The answer and the reasoning

C. mTOR signalling

Hamartin (TSC1) and tuberin (TSC2) form a complex that inhibits mTOR. Loss of either releases mTOR, increasing growth and protein synthesis, and the hamartomas respond to mTOR inhibitors such as everolimus.

Option by option

  • A. Wnt/beta-catenin signalling

    Wnt/beta-catenin is dysregulated by APC loss in familial adenomatous polyposis.

  • B. Hedgehog signalling

    Hedgehog signalling is activated by PTCH1 loss in Gorlin syndrome.

  • C. mTOR signalling (correct)

    Correct. Loss of the TSC1/TSC2 brake leaves mTOR overactive.

  • D. Notch signalling

    Notch signalling is activated in T-cell acute lymphoblastic leukaemia.

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 Pathology question

What is the answer to this Pathology question?

The best answer is C, mTOR signalling. Hamartin (TSC1) and tuberin (TSC2) form a complex that inhibits mTOR.

Why is "Wnt/beta-catenin signalling" not the answer?

Wnt/beta-catenin is dysregulated by APC loss in familial adenomatous polyposis.

Why is "Hedgehog signalling" not the answer?

Hedgehog signalling is activated by PTCH1 loss in Gorlin syndrome.

Why is "Notch signalling" not the answer?

Notch signalling is activated in T-cell acute lymphoblastic leukaemia.

What concept does this question test?

It tests Neoplasia: tuberous sclerosis pathway in Pathology. Loss of either releases mTOR, increasing growth and protein synthesis, and the hamartomas respond to mTOR inhibitors such as everolimus.

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: tuberous sclerosis pathway?

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.