Neoplasia: sentinel lymph node: 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: sentinel lymph node

Sample item

A 52-year-old woman has a 2-cm invasive ductal carcinoma of the breast with a clinically node-negative axilla. A sentinel lymph node biopsy is planned. What does the term sentinel node mean, and what does a negative result imply?

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

The answer and the reasoning

C. The first node draining the tumour, so a negative result makes involvement of other axillary nodes unlikely

The sentinel node is the first lymph node to receive lymph from the tumour, identified using blue dye or radiotracer. If it is free of tumour, the remaining nodes in the basin are very likely free, so complete axillary clearance and its morbidity, such as lymphoedema, can be avoided.

Option by option

  • A. The node with the highest nodal level, so a negative result confirms stage I disease

    The sentinel node is defined by drainage order, not nodal level, and final stage also depends on tumour size and distant disease.

  • B. The largest axillary node, so a negative result excludes distant metastasis

    Size does not define a sentinel node, and a negative node cannot exclude haematogenous distant spread.

  • C. The first node draining the tumour, so a negative result makes involvement of other axillary nodes unlikely (correct)

    The first draining node is the one most likely to harbour early metastasis, so its status predicts the rest of the basin.

  • D. A random axillary node, so a negative result provides no information

    A sentinel node is identified deliberately by mapping, which is what makes it informative.

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, The first node draining the tumour, so a negative result makes involvement of other axillary nodes unlikely. The sentinel node is the first lymph node to receive lymph from the tumour, identified using blue dye or radiotracer.

Why is "The node with the highest nodal level, so a negative result confirms…" not the answer?

The sentinel node is defined by drainage order, not nodal level, and final stage also depends on tumour size and distant disease.

Why is "The largest axillary node, so a negative result excludes distant meta…" not the answer?

Size does not define a sentinel node, and a negative node cannot exclude haematogenous distant spread.

Why is "A random axillary node, so a negative result provides no information" not the answer?

A sentinel node is identified deliberately by mapping, which is what makes it informative.

What concept does this question test?

It tests Neoplasia: sentinel lymph node in Pathology. If it is free of tumour, the remaining nodes in the basin are very likely free, so complete axillary clearance and its morbidity, such as lymphoedema, can be avoided.

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: sentinel lymph node?

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.