# Leukaemias and Myeloproliferative Neoplasms for NEET PG Pathology: ALL, AML, CLL, CML, MDS, Polycythaemia Vera

Source: https://tracknation.in/story/leukaemias-and-myeloproliferative-neoplasms-for-neet-pg-pathology-all-aml-cll-cml-mds-polycythaemia-vera (TrackNation — free UPSC notes with PYQs)

> NEET PG Pathology: neutropenia grades and leukaemoid reaction, acute vs chronic leukaemias, ALL, AML with Auer rods and APL, CLL markers, CML and the Philadelphia chromosome, myelodysplastic syndromes, polycythaemia vera, essential thrombocythaemia and myelofibrosis, with a diagram, hooks, vignette MCQs and cards.

## Start Here

🎯 **Exam priority: Very high.** *Expect: a child with bone pain and blasts (ALL), Auer rods, APL treated with tretinoin,
an elderly man with lymphocytosis (CLL markers), massive spleen with Philadelphia chromosome, and a leukaemoid reaction vs CML.*

CBME mapping: **PA 18.1–18.2**.

## White-Cell Counts: Low and High

- **Neutropenia**: below 1500/µL (lower normal in Black people); moderate 500–1000; severe < 500, when gut and mouth flora
start causing infections.

- **Leukaemoid reaction**: neutrophils > 50,000/µL without malignant transformation — usually from another cancer or a
systemic infection; it can be mimicked by CML.

## The Four Leukaemias

*ALL, AML, CLL and CML compared, from MSD's comparison table. Drawn by TrackNation.*

- **Acute** leukaemias have immature blasts; **chronic** ones have more mature cells. Pancytopenia with
blasts on the smear suggests acute leukaemia.

- **ALL**: commonest childhood cancer; 60% of cases in children, peak 2–5 years; TdT positive (lymphoid); can infiltrate the
CNS and testes.

- **AML**: myeloperoxidase positive (myeloid); Auer rods are crystallised MPO granules. **APL**: t(15;17) PML::RARA,
treated with tretinoin and arsenic trioxide.

- **CLL**: CD5+ B cells expressing CD5, CD19, CD20, CD23; hypogammaglobulinaemia in up to two-thirds; autoimmune haemolysis;
can transform to diffuse large B-cell lymphoma (Richter).

- **CML**: t(9;22) — ABL from chromosome 9 fuses to BCR on 22 (Philadelphia chromosome, > 90%); low leukocyte alkaline
phosphatase; rising basophils herald progression; treated with tyrosine kinase inhibitors.

## Myelodysplastic and Myeloproliferative Neoplasms

- **MDS**: marrow failure with < 20% blasts (not enough for AML); 40–60% evolve into AML. **Del(5q)**: severe
anaemia with thrombocytosis.

- **Polycythaemia vera**: JAK2 (rarely CALR) mutation; aquagenic pruritus (itch after hot water); treated with phlebotomy,
low-dose aspirin, ruxolitinib or interferon.

- **Essential thrombocythaemia**: JAK2 V617F in about 50%.

- **Primary myelofibrosis**: marrow fibrosis, extramedullary haematopoiesis in the spleen, teardrop and nucleated red cells.

## Traps the Examiner Sets

- TdT = lymphoid (ALL); myeloperoxidase and Auer rods = myeloid (AML).

- APL: t(15;17), treated with tretinoin and arsenic.

- Leukaemoid reaction vs CML: CML has the Philadelphia chromosome and low LAP.

- Itching after a hot shower with high haemoglobin: polycythaemia vera (JAK2).

## Memory Hooks & Shortcuts

*Shortcuts to lock in this article's numbers and lists. Each one only re-packages facts proven above.*

- 🧠 **TdT = Toddler's leukaemia (ALL)** — lymphoid marker

- 🧠 **Auer = AML** — MPO rods in myeloblasts

- 🧠 **APL: 15 + 17, Retinoic and arsenic Rescue** — t(15;17), tretinoin, arsenic

- 🧠 **CML: 9 and 22, BCR-ABL, Philadelphia's Pair** — t(9;22)

- 🧠 **CLL: Five-Twenty-Three (CD5, CD23)** — markers

- 🧠 **PV: Hot shower Itch, JAK2** — aquagenic pruritus

## Rapid-Revision Cards

- < 1500; moderate 500–1000; severe < 500.

- Neutrophils > 50,000, non-malignant; cancer or infection.

- Blasts vs more mature cells.

- Commonest childhood cancer; peak 2–5 y; TdT+; CNS, testes.

- MPO+; Auer rods.

- t(15;17) PML::RARA; tretinoin + arsenic.

- CD5, 19, 20, 23; hypogammaglobulinaemia; AIHA.

- CLL → diffuse large B-cell lymphoma.

- t(9;22) BCR::ABL1; Ph+ > 90%; low LAP; TKI.

- Rising basophils and blasts.

- < 20% blasts; 40–60% → AML.

- Severe anaemia + thrombocytosis.

- JAK2; aquagenic pruritus; phlebotomy, aspirin.

- JAK2 V617F ~50%.

- Teardrop cells; splenic EMH.

## Sources

*Facts in this article were checked against these documents.*

- MSD Manual Professional: Overview of Leukemia; Acute Lymphoblastic Leukemia; Acute Myeloid Leukemia; Chronic Lymphocytic Leukemia; Chronic Myeloid Leukemia; Myelodysplastic Syndromes; Neutropenia; Polycythemia Vera; Essential Thrombocythemia; Primary Myelofibrosis — Merck & Co. (MSD Manuals), reviewed 2025–2026 (link)

- Competency Based Undergraduate Curriculum, Pathology (PA 18) — National Medical Commission, 2024

## Test Yourself: Practice Questions

Twenty-five questions in NEET PG style, most of them clinical vignettes.

## Practice Questions (NEET PG pattern)

*Original questions written in the style of the exam: +4 for a correct answer, −1 for a wrong one. Every answer
was checked against the sources listed above. NEET PG papers are not published by NBEMS, so these are not past-paper questions.*

**Q1.** A 4-year-old has fever, pallor, bruising and bone pain; the smear shows pancytopenia with blasts that are TdT positive. The diagnosis is

- (a) acute myeloid leukaemia

- (b) acute lymphoblastic leukaemia

- (c) aplastic anaemia

- (d) CLL

**Answer: (b)** — Commonest childhood cancer; peak 2–5 years; TdT marks lymphoid cells.

**Q2.** The commonest cancer in children is

- (a) retinoblastoma

- (b) acute lymphoblastic leukaemia

- (c) Wilms tumour

- (d) neuroblastoma

**Answer: (b)** — MSD.

**Q3.** Without prophylaxis, a leukaemia that commonly involves the central nervous system is

- (a) CLL

- (b) ALL

- (c) CML

- (d) AML

**Answer: (b)** — MSD comparison table; also testicular infiltration.

**Q4.** A 50-year-old has blasts with linear azurophilic cytoplasmic inclusions that stain for myeloperoxidase. The inclusions are

- (a) Heinz bodies

- (b) Dohle bodies

- (c) Howell-Jolly bodies

- (d) Auer rods (AML)

**Answer: (d)** — Crystallised MPO-rich granules.

**Q5.** Acute promyelocytic leukaemia carries the translocation

- (a) t(11;14)

- (b) t(15;17) PML::RARA

- (c) t(8;14)

- (d) t(9;22) BCR::ABL1

**Answer: (b)** — MSD AML page.

**Q6.** APL is now commonly treated without conventional chemotherapy using

- (a) hydroxyurea alone

- (b) rituximab

- (c) imatinib

- (d) tretinoin and arsenic trioxide

**Answer: (d)** — Very well tolerated.

**Q7.** A 70-year-old man has painless lymphadenopathy and a lymphocyte count of 40,000/µL; cells express CD5, CD19, CD20 and CD23. The diagnosis is

- (a) chronic lymphocytic leukaemia

- (b) CML

- (c) infectious mononucleosis

- (d) ALL

**Answer: (a)** — CD5+ B cells.

**Q8.** A CLL patient has recurrent bacterial infections. A likely cause is

- (a) neutrophilia

- (b) iron overload

- (c) hypogammaglobulinaemia (in up to two-thirds)

- (d) hypersplenism only

**Answer: (c)** — MSD.

**Q9.** A man with long-standing CLL suddenly develops rapidly enlarging nodes and fever; biopsy shows diffuse large B-cell lymphoma. This is

- (a) Hodgkin lymphoma

- (b) blast crisis of CML

- (c) leukaemoid reaction

- (d) Richter syndrome

**Answer: (d)** — MSD.

**Q10.** A 45-year-old has massive splenomegaly, a very high white count with the whole myeloid series, and low leukocyte alkaline phosphatase. The key test is

- (a) Philadelphia chromosome / BCR::ABL1

- (b) JAK2 alone

- (c) TdT staining

- (d) flow cytometry for CD55

**Answer: (a)** — CML: Ph-positive in > 90%.

**Q11.** In CML, the Philadelphia chromosome arises from

- (a) t(8;14)

- (b) t(9;22), fusing ABL from chromosome 9 to BCR on chromosome 22

- (c) t(15;17)

- (d) deletion of 5q

**Answer: (b)** — MSD.

**Q12.** First-line treatment of chronic-phase CML is

- (a) a tyrosine kinase inhibitor

- (b) rituximab

- (c) splenectomy

- (d) tretinoin

**Answer: (a)** — MSD.

**Q13.** In a patient with CML, increasing blood basophils and blasts suggest

- (a) infection only

- (b) progression to accelerated phase

- (c) response to treatment

- (d) iron deficiency

**Answer: (b)** — MSD accelerated-phase features.

**Q14.** A man with severe pneumonia has neutrophils of 60,000/µL; no blasts or Philadelphia chromosome. This is

- (a) AML

- (b) a leukaemoid reaction

- (c) CML

- (d) CLL

**Answer: (b)** — Neutrophils > 50,000/µL without malignant transformation.

**Q15.** A patient on chemotherapy has an absolute neutrophil count of 300/µL. The neutropenia is

- (a) moderate

- (b) normal

- (c) mild

- (d) severe (< 500), with risk of infection from own gut and mouth flora

**Answer: (d)** — MSD grades.

**Q16.** MSD gives the usual lower limit of a normal absolute neutrophil count in adults (somewhat lower in some ethnic groups) as about

- (a) 500/µL

- (b) 1500/µL

- (c) 4000/µL

- (d) 100/µL

**Answer: (b)** — Somewhat lower in Black patients.

**Q17.** An elderly patient has cytopenias, a dysplastic marrow and 12% blasts. The diagnosis is

- (a) AML

- (b) aplastic anaemia

- (c) myelodysplastic syndrome (blasts < 20%)

- (d) CLL

**Answer: (c)** — 40–60% evolve into AML.

**Q18.** An older woman has severe anaemia with a raised platelet count; marrow cytogenetics shows deletion of the long arm of chromosome 5. This is

- (a) CML

- (b) essential thrombocythaemia

- (c) MDS with isolated del(5q)

- (d) iron deficiency

**Answer: (c)** — MSD.

**Q19.** A man has a raised haemoglobin and itching after hot showers. The test to order is

- (a) TdT

- (b) JAK2 mutation

- (c) BCR::ABL1

- (d) CD5

**Answer: (b)** — Polycythaemia vera: aquagenic pruritus.

**Q20.** Treatment of polycythaemia vera includes

- (a) iron supplements

- (b) splenectomy first

- (c) erythropoietin

- (d) phlebotomy and low-dose aspirin (ruxolitinib or interferon if needed)

**Answer: (d)** — MSD.

**Q21.** In essential thrombocythaemia, the JAK2 V617F mutation is found in about

- (a) 90%

- (b) 5%

- (c) 50% of patients

- (d) 100%

**Answer: (c)** — MSD.

**Q22.** A man with splenomegaly and marrow fibrosis has teardrop and nucleated red cells. The diagnosis is

- (a) ALL

- (b) primary myelofibrosis

- (c) CML

- (d) iron deficiency

**Answer: (b)** — Extramedullary haematopoiesis mainly in the spleen.

**Q23.** Myeloperoxidase staining is positive in

- (a) red cells

- (b) lymphoid cells

- (c) myeloid cells (AML)

- (d) plasma cells

**Answer: (c)** — TdT marks lymphoid cells.

**Q24.** Compared with acute leukaemias, chronic leukaemias have

- (a) no spleen involvement

- (b) more mature cells

- (c) more blasts

- (d) always pancytopenia

**Answer: (b)** — MSD.

**Q25.** A patient with a very high white count and splenomegaly has a low leukocyte alkaline phosphatase (LAP) score. This favours

- (a) primary myelofibrosis

- (b) polycythaemia vera

- (c) a reaction to infection

- (d) chronic myeloid leukaemia

**Answer: (d)** — MSD: raised LAP suggests a myeloproliferative neoplasm; decreased LAP suggests CML.

### Active Recall

From memory: define neutropenia grades and a leukaemoid reaction; contrast ALL, AML, CLL and CML (cells, markers, counts, nodes, spleen, genetics, treatment); and describe MDS, polycythaemia vera, essential thrombocythaemia and myelofibrosis.