Characteristics of BM

Question 1

List 3 reasons/indications for a BM aspirate

Answer 1

• cytopenia, bicytopenia, pancytopenia
• Persistent RBC, WBC abnnormality
• haematological neoplasia

Question 2

List 3 reasons/indications for a BM trephine biopsy

Answer 2

• fail/inconclusive BM aspiration
• accurate assessment of cellularity, architecture, vascular system
• Suspect focal lesion, BM fibrosis

Question 3

why is at least 1 squash sample required for a BM aspirate (not just wedge-smear)

Answer 3

bc cells of interest may be trapped w/in marrow particles

Question 4

How might the wedge method affect cellular characteristics?

Answer 4

Wedge method is prone to haemodilution => dec cellularity => less reliable interpretation

Question 5

What are pitfalls of BM assessment

Answer 5

• inappropriate collection of BM i.e. not needed (e.g. wrong collection => false interpretation e.g. pancytopenia but collected on same drip)
• BM aspirate not interpreted w/ trephine biopsy
• aspirate is misinterpreted

Question 6

What are the effects of excess EDTA on BM cells

Answer 6

• damage nuclear & cytoplasmic membrane
• Non-lobulated nucleus in nuetrophils
• Small cells (Cytoplasmic & nuclear contraction)

Question 7

what are the 3 stages of cytotoxic chemotherapy on the BM

Answer 7

1. wk 1: cell death
2. wk 1-2: hypocellularity
3. wk 2: regeneration (*check for neoplasm & if BM regenerating normally)

Question 8

Describe the cellularity of BM on the 1-2 wks (10-14 days) after cytotoxic chemotherapy (3-4)

Answer 8

• inc lymphoc,
• adipocytes shrunken,
• marrow sinusoid contain fibrin, haemorrh, faomy macrophages
• (persistent blast = poor prognosis)

Question 9

Describe the regeneration of BM on 2nd wk after cytotoxic chemotherapy (order of appearance)

Answer 9

order of appearance
1. small erythroid colonies
2. myeloid precursorcells
3. megakaryocytes
4. haematopoitic dysplasi may be evident
5. hyperplasia may resut = inc blast cells
(PB reflects BM composition = immature)

Question 10

Describe the effects on the BM after radiotherapy (@ 2wks & 2-3 months)

Answer 10

• 2 wks: odema & necrosis; osteopenia, osteosclerosis, focal fibrosis, inflammation
• 1-2 mth: Adipose tiss. replace haematopoetic tiss => hypoplasia (/aplasia) & persistent cytopenia

Question 11

Whats the % of pts that get therapy related myeloid neoplasms?

Answer 11

<2% of pts undergoing chemoth.

Question 12

Which factors can cause therapy related neoplasms in th 3 cell lines & briefly describe effect/result

Answer 12

• RBC: Epo => inc cellularity & erythropoeisis, dec intracell. Fe stores (exhausted), dec Mye:Ery
• WBC: granulocyte & Granulo. macroph, colony stim. factors => inc [WBC]; *neutro (mature & immature - blast, L-shift)
• Plt: Tpo => Inc MKpoeisis = atypical MK in BM & MK in PB; inc plt in PB, fibrosis in BM

Question 13

Describe the complications of collecting a BM biopsy

Answer 13

• haemorrhage
• needle breaks
• infection at collection site