Haematology: secondary polycythaemia: practice question

A General Medicine 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.

Try it

General Medicine · Haematology: secondary polycythaemia

Sample item

A 60-year-old smoker with severe COPD has a haemoglobin of 19 g/dL. Which pattern supports secondary polycythaemia rather than polycythaemia vera?

ARaised leucocyte and platelet counts with splenomegalyBRaised erythropoietin with low arterial oxygen saturationCLow erythropoietin with JAK2 V617F mutationDNormal oxygen saturation with low erythropoietin

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

The answer and the reasoning

B. Raised erythropoietin with low arterial oxygen saturation

In secondary polycythaemia, hypoxia drives appropriate erythropoietin production, so EPO is high. Polycythaemia vera is a clonal JAK2-driven disorder with suppressed EPO, often with leucocytosis, thrombocytosis and splenomegaly. Treating the hypoxia, for example with oxygen, is the key.

Option by option

A. Raised leucocyte and platelet counts with splenomegaly
Pan-myeloproliferation with splenomegaly favours polycythaemia vera.
B. Raised erythropoietin with low arterial oxygen saturation (correct)
Correct. Hypoxia-driven high EPO indicates a secondary cause.
C. Low erythropoietin with JAK2 V617F mutation
Low EPO with JAK2 mutation indicates polycythaemia vera.
D. Normal oxygen saturation with low erythropoietin
Low EPO with normal saturation also points to polycythaemia vera.

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 General Medicine question

What is the answer to this General Medicine question?

The best answer is B, Raised erythropoietin with low arterial oxygen saturation. In secondary polycythaemia, hypoxia drives appropriate erythropoietin production, so EPO is high.

Why is "Raised leucocyte and platelet counts with splenomegaly" not the answer?

Pan-myeloproliferation with splenomegaly favours polycythaemia vera.

Why is "Low erythropoietin with JAK2 V617F mutation" not the answer?

Low EPO with JAK2 mutation indicates polycythaemia vera.

Why is "Normal oxygen saturation with low erythropoietin" not the answer?

Low EPO with normal saturation also points to polycythaemia vera.

What concept does this question test?

It tests Haematology: secondary polycythaemia in General Medicine. Polycythaemia vera is a clonal JAK2-driven disorder with suppressed EPO, often with leucocytosis, thrombocytosis and splenomegaly. Treating the hypoxia, for example with oxygen, is the key.

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: secondary polycythaemia?

For each disease know the classic presentation, the best test, and the first-line treatment. Then use the flashcards and the other General Medicine 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.