Head and neck tumours: depth of invasion in oral cancer staging: practice question

A ENT 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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ENT · Head and neck tumours: depth of invasion in oral cancer staging

Sample item

A 4 cm lateral tongue carcinoma has a depth of invasion of 12 mm and no extranodal extension. In the AJCC eighth edition, how does depth of invasion affect T category?

ADepth of invasion above 10 mm upstages the tumour by one category from the size-based TBDepth of invasion is not consideredCDepth below 5 mm is automatically T4DDepth of invasion only matters for the N category

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

The answer and the reasoning

A. Depth of invasion above 10 mm upstages the tumour by one category from the size-based T

In the eighth edition, depth of invasion modifies oral cavity T staging: for a tumour 2 cm or less, a depth over 5 mm upgrades it to T2, and for tumours of 2 to 4 cm, a depth over 10 mm upgrades to T3. A 4 cm tumour with 12 mm depth is therefore T3. Depth is measured from the basement membrane of adjacent normal mucosa.

Option by option

A. Depth of invasion above 10 mm upstages the tumour by one category from the size-based T (correct)
Correct. Greater depth of invasion upstages the T category.
B. Depth of invasion is not considered
It is a key addition in the eighth edition.
C. Depth below 5 mm is automatically T4
Shallow tumours are not T4 on depth alone.
D. Depth of invasion only matters for the N category
It modifies the T category, not N.

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 ENT question

What is the answer to this ENT question?

The best answer is A, Depth of invasion above 10 mm upstages the tumour by one category from the size-based T. In the eighth edition, depth of invasion modifies oral cavity T staging: for a tumour 2 cm or less, a depth over 5 mm upgrades it to T2, and for tumours of 2 to 4 cm, a depth over 10 mm upgrades to T3.

Why is "Depth of invasion is not considered" not the answer?

It is a key addition in the eighth edition.

Why is "Depth below 5 mm is automatically T4" not the answer?

Shallow tumours are not T4 on depth alone.

Why is "Depth of invasion only matters for the N category" not the answer?

It modifies the T category, not N.

What concept does this question test?

It tests Head and neck tumours: depth of invasion in oral cancer staging in ENT. A 4 cm tumour with 12 mm depth is therefore T3. Depth is measured from the basement membrane of adjacent normal mucosa.

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 Head and neck tumours: depth of invasion in oral cancer staging?

Learn tuning fork results and audiogram patterns by sketching them. Then use the flashcards and the other ENT 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.