Breast pathology: 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 · Breast pathology

Sample item

A woman has an ill-defined breast mass. Histology shows small discohesive cells infiltrating the stroma in single files, with some signet ring cells. Which molecular abnormality is characteristic of this tumour?

AHER2 gene amplification as the defining lesionBGermline BRCA1 mutation as the defining lesionCLoss of E-cadherin expressionDAbsence of oestrogen receptor expression

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

The answer and the reasoning

C. Loss of E-cadherin expression

This is invasive lobular carcinoma, in which loss of E-cadherin (CDH1) causes the cells to lose cohesion and infiltrate in single files. Most of these tumours are strongly oestrogen receptor positive and are often multicentric or bilateral.

Option by option

A. HER2 gene amplification as the defining lesion
HER2 amplification is uncommon in invasive lobular carcinoma and does not define it.
B. Germline BRCA1 mutation as the defining lesion
BRCA1 mutations are linked mainly to high-grade, triple-negative ductal-type cancers rather than lobular carcinoma.
C. Loss of E-cadherin expression (correct)
Correct. E-cadherin loss explains the discohesive, single-file growth pattern.
D. Absence of oestrogen receptor expression
Invasive lobular carcinoma is usually oestrogen receptor positive, so absence of the receptor is not characteristic.

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 Pathology question

What is the answer to this Pathology question?

The best answer is C, Loss of E-cadherin expression. This is invasive lobular carcinoma, in which loss of E-cadherin (CDH1) causes the cells to lose cohesion and infiltrate in single files.

Why is "HER2 gene amplification as the defining lesion" not the answer?

HER2 amplification is uncommon in invasive lobular carcinoma and does not define it.

Why is "Germline BRCA1 mutation as the defining lesion" not the answer?

BRCA1 mutations are linked mainly to high-grade, triple-negative ductal-type cancers rather than lobular carcinoma.

Why is "Absence of oestrogen receptor expression" not the answer?

Invasive lobular carcinoma is usually oestrogen receptor positive, so absence of the receptor is not characteristic.

What concept does this question test?

It tests Breast pathology in Pathology. Most of these tumours are strongly oestrogen receptor positive and are often multicentric or bilateral.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Breast pathology?

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.