Haematology: acute lymphoblastic leukaemia: 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 · Haematology: acute lymphoblastic leukaemia

Sample item

A 5-year-old child has pallor, bone pain, hepatosplenomegaly and lymphadenopathy. The smear shows blasts with scant cytoplasm and no granules that are negative for myeloperoxidase. Which flow cytometry profile is expected?

AMyeloperoxidase, CD13 and CD33 positiveBCD3 and CD7 positive with a mediastinal massCCD5, CD23 and CD19 positive with weak surface immunoglobulinDTdT, CD10 and CD19 positive

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

The answer and the reasoning

D. TdT, CD10 and CD19 positive

Most childhood acute lymphoblastic leukaemia is of precursor B-cell type and expresses terminal deoxynucleotidyl transferase (TdT), CD10 (CALLA), CD19 and CD79a. Blasts are myeloperoxidase negative. Favourable features include age 2 to 10 years, low white count and the t(12;21) translocation.

Option by option

A. Myeloperoxidase, CD13 and CD33 positive
Myeloperoxidase with CD13 and CD33 indicates myeloid differentiation, as in AML.
B. CD3 and CD7 positive with a mediastinal mass
CD3 and CD7 positivity with a mediastinal mass suggests T-cell ALL, typically in adolescent boys.
C. CD5, CD23 and CD19 positive with weak surface immunoglobulin
CD5, CD23 and CD19 with weak surface immunoglobulin is the profile of chronic lymphocytic leukaemia in older adults.
D. TdT, CD10 and CD19 positive (correct)
Correct. TdT with CD10 and CD19 defines precursor B-cell ALL.

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 D, TdT, CD10 and CD19 positive. Most childhood acute lymphoblastic leukaemia is of precursor B-cell type and expresses terminal deoxynucleotidyl transferase (TdT), CD10 (CALLA), CD19 and CD79a.

Why is "Myeloperoxidase, CD13 and CD33 positive" not the answer?

Myeloperoxidase with CD13 and CD33 indicates myeloid differentiation, as in AML.

Why is "CD3 and CD7 positive with a mediastinal mass" not the answer?

CD3 and CD7 positivity with a mediastinal mass suggests T-cell ALL, typically in adolescent boys.

Why is "CD5, CD23 and CD19 positive with weak surface immunoglobulin" not the answer?

CD5, CD23 and CD19 with weak surface immunoglobulin is the profile of chronic lymphocytic leukaemia in older adults.

What concept does this question test?

It tests Haematology: acute lymphoblastic leukaemia in Pathology. Blasts are myeloperoxidase negative. Favourable features include age 2 to 10 years, low white count and the t(12;21) translocation.

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 Haematology: acute lymphoblastic leukaemia?

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.