Leukaemia

Question 1

What is leukaemia?

Answer 1

• neoplastic condition of the bone marrow in which neoplastic cells of lymphoid or non-lymphoid stem cells or their progeny undergo clonal expansion with or without cellular differentiation

Question 2

Clinical signs due to:

Answer 2

• Failure of normal marrow function
• Infiltrated organ dysfunction
• Hyperviscosity of blood (which can increase presence/incidence of thrombosis)
• Paraneoplastic syndromes (e.g., IMHA, hypercalcaemia)

Question 3

What tissues may leukaemia cells released into the circulation infiltrate?

Answer 3

• liver
• spleen
• LN

Question 4

ALL

Answer 4

= acute lymphoid leukaemia

Question 5

AML

Answer 5

= acute myeloid leukaemia

Question 6

Which is more responsive to aggressive chemo - ALL or AML?

Answer 6

• ALL

Question 7

Acute leukaemia - cytology

Answer 7

• can’t tell the difference between lineages (e.g. what this cell type is) as proliferate from stem cells and haven’t matured/differentiated to the point where morphological distinctions can be made
• very big cells

Question 8

How does immunophenotyping work to determine the morphology of acute leukaemia?

Answer 8

• lab antibodies against cell surface markers (antigens) tells us origin
• use immuno-labelled flow cytometry of EDTA blood or marrow

Question 9

How does lymphocyte clonality PCR work to differentiate acute leukaemia types?

Answer 9

• uses T-cell & B-cell primers to differentiate between B- & T-cell origin

Question 10

Why is it easy to distinguish the lineage of cells in chronic leukaemia?

Answer 10

• in chronic leukaemia the relevant WBCs look close to normal appearance, there are just WAY to many of them and very large (4x size of small lymphocytes)

Question 11

Chronic neutrophilic leukaemia - cytology

Answer 11

• majority are mature, segmented neutrophils

Question 12

How to differentiate a chronic leukaemia from an infection

Answer 12

• numbers high above reference range with continuous increase = neoplastic

Question 13

What does pancytopenia indicate? (in context of cancer/case suspicious of cancer)

Answer 13

• ablation of normal bone marrow

Question 14

Once you have diagnosed acute leukaemia, how would you progress?

Answer 14

• send for flow cytology which will detect antigens on surface of cells and enable us to determine if cells are lymphoid or myeloid in origins -> steers tx options

Question 15

What is lymphoma?

Answer 15

• tumour of the lymphocytes that arises in the LN

Question 16

What is myelodysplasia?

Answer 16

• a pre-neoplastic condition
• <20% marrow blasts, cytopaenia and disrupted haematopoiesis

Question 17

What % of leukaemia are aleukaemic?

Answer 17

• ~10%
• instead there may be atypical cells +/- cytopaenias

Question 18

Acute vs chronic leukaemia

Answer 18

Acute:
- neoplastic transformation during stem cell proliferation
- aggressive rapid disease
- cytopaenia very common (marrow disrupted by neoplastic expansion)

Chronic:
- neoplastic transformation following differentiation
- slow progression and less aggressive cf aute
- cytopaenia is rare

Question 19

When there is marrow disruption, which cells disappear first? then what?

Answer 19

• neutrophils (hours)
• platelets (days)
• RBCs (months)

Question 20

Lymphoma with a leukaemia phase

Answer 20

• In severe cases: stage V lymphoma
• goes to bone marrow -> infiltrates the bone marrow and then get them circulating

Question 21

Lymphoma vs lymphoid leukaemia

Answer 21

Lymphoma involving BM:
- <25% blast cells in marrow
- Lower circulating blast count
- Mild or absent cytopenia
- Massive lymphadenopathy
- May not be systemically ill

ALL:
- >25% blast cells in marrow
- Higher circulating blast count
- Severe cytopenia
- Mild to moderate lymphadenopathy
- Usually systemically ill