Cytology in practice Flashcards

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1
Q

Why do cytology?

A

quick, easy, cheap, non-invasive, low risk, screening tool, can establish a diagnosis or disease process

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2
Q

Limitations - cytology

A

relies on sample quality (collector skill, smear, tissu eexfoliation, site of collection), interpreter of smears, no information about tissue architecture (vs histopathology), diagnostic challenges

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3
Q

Histopathology - advantages

A

more expensive (sterile), slow (48 hr), poor detail for round cell tumours

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4
Q

Histopathology - disadvantages

A

tissue architecture, tumour grading, immunohistochemistry more available.

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5
Q

What samples can you take for cytology?

A

ASPIRATION OR IMPRINTS: superficial masses, LN, organs and deep masses
FLUIDS: body cavity, joints, respiratory space, CSF

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6
Q

When to do fine needle biopsy?

A

solid or fluid filled masses, visual or US guidance, no negative pressure applied to syringe, small guage needle (22-24), insert into mass several times, masses with necrotic centre you must sample the wall not just the centre then use air filled syringe to expel cells onto slide.

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7
Q

Distinguish FNA and FNP

A

FNA = fine needle aspirate. negative pressure applied to syringe. use only if FNB not possible.

FNB = fine needle biopsy, NO negative pressure applied to syringe. first choice method.

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8
Q

What makes a smear of a good quality? 3

A

cells nicely spread out, not ruptured, not just chromatin fibres from nuclei visible.

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9
Q

3 goals of smear preparation

A

thin areas with good cell spread, minimise cell damage, minimise blood content

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10
Q

Another name for a touch impression?

A

Imprint

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11
Q

What are imprints good for?

A

Evaluation of excised tissue or superficial lesions. Made before the tissue is placed in 10% buffered formalin and submitted for histopathology

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12
Q

How to make an imprint

A

Use fresh cute surface of tissue, blot until dry, imprint directly onto glass slide, tissue should be roled agaunst the slide, 4-5 imprints per slide, allow to air dry and then stain.

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13
Q

How is fluid collected? 3

A

With EDTA - clot prevention
sterile pot - bacteriology
fresh - slide preparation (direct smear, line preparation, squash preparation, concentration techniques)

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14
Q

What is the most important thing to determine from a cytology smear?

A

Inflammatory or neoplastic

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15
Q

What to determine if lesion is inflammatory

A

Septic or non-septic

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16
Q

What to determine if lesion is neoplastic

A

Round cell, epithelial or spindle cell

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17
Q

Indicators of sample quality - 5

A
  • enough cells to examine
  • preservation of cells
  • adequate spreading
  • representative of the lesion?
  • do we expect normal cells/what are normal cells from this area?
18
Q

How to tell if sample is inflammatory?

A

Dominated by inflammatory cells - neutrophils, eosinophils, lymphocytes, macrophages

19
Q

How to tell if sample is neoplastic?

A

Sample dominated by tissue cells

20
Q

What if the sample is BOTH inflammatory AND neoplastic?

A

Need experience/2nd opinion to tell if:

  • inflammation with secondary dysplasia OR
  • neoplasia with secondary inflammation
21
Q

Indicators of septic inflammation

A

contains bacteria/organisms, degenerate/lytic neutrophils, bacteria must be intracellular, if extracellular may be contaminants

22
Q

Indicators of non-septic inflammation

A

no bacteria or organisms seen, neutrophils are non-degenerate, lack of identifiable bacteria and presence of non-degenerate neutrophils

23
Q

Outline degenerative changes in neutrophils 4

A
  • nuclear change
  • nucleus swells, loses lobulation and becomes paler (chromatin less condensed)
  • secondary to release of bacterial toxins
  • if present, consider septic inflammation even if bacteria not seen.
24
Q

What does an increased number of macrophages suggest? What if neutrophils are present too?

A
  • Inflammatory lesion - a granulomatous inflammation (e.g. mycobacterium spp).
  • If neutrophils too - pyogranulomatous inflammation (fungal infections).
25
Q

What inflammatory reaction is seen with a FB?

A

Either granulomatous or pyogranulomatous

26
Q

Describe round cells - 6

A

individual cells, small to medium size, round to oval cells and nuclei, well defined cell broders, good cell yield

27
Q

List the finite list of Round (discrete) cell tumours - 6

A

lymphoma, plasmacytoma, histiocytoma, mast cell tumour, transmissible venereal tumour (TVT), (melanoma)

28
Q

Describe epithelial cells

A

often found in sheets/rafts/clusters, large cell size, cell to cell junctions, oval to angular in shape, round nuclei which are centrally located, cytoplasm often abundant, good cell yield.

29
Q

Examples of epithelial cell tumours

A

sebaceous, mammary, liver

30
Q

Describe mesenchymal cells

A

individual cells or clumps, small to medium size cells, spindle to fusiform to stellate, indistinct cell borders, elongated nucleus, poor exfoliation, matrix production (collagen, osteoid).

31
Q

Name for benign epithelial tumour

A

adenoma

32
Q

Define carcinoma

A

Malignant epithelial cell

33
Q

Define fibroma

A

benign mesenchymal tumour

34
Q

What is a malignant mesenchymal tumour called?

A

fibrosarcoma

35
Q

What does the behaviour of plasmacytoma tumours depend on?

A

Depends on type

36
Q

What are criteria of malignancy?

A

Cytoplasmic and nuclear features:

  • uniformity vs. pleomorphism (carcinoma, sarcoma)
  • monotony (lymphoma)
  • nuclear criteria are most reliable
  • need at least 3 nuclear criteria of malignancy before calling a tumour malignant
37
Q

Define anisocytosis

A

variation in cell size

38
Q

Cellular criteria of malignancy 3

A

anisocytosis, macrocytosis, cell crowding

39
Q

Nuclear criteria of malignancy - 11

A

anisokaryosis, multinucleation (vary in size, odd numbers of nuclei), macrocytosis, high N:C ratio (in large cells), increased mitotic figures, abnormal mitotic figures, coarse chromatin, nuclear moulding,macronucleoli, varying nucleolar shape and size

40
Q

Important points to remember when submititng samples to the lab - 8

A

send multiple unstained smears, label slides/tubes, use pencil, signalment, history, important clinical findings, describe location of lesion, duration and rate of growth, previous lesions and diagnosis, current therapy

41
Q

Common problems with cytology samples - 5

A

formalin fumes (ruins blood smears), refrigerating glass slides (–> shatter), breakage during shipping, lack of freshly made smears, (flies)

42
Q

What are the most common causes of masses/tumours and are easy to identify? 4

A

lipoma, mast cell tumour, melanoma, follicular cyst