Cytology Flashcards

1
Q

How to Make a CellBlock

A

Centrifuge sample and discard supernatant.

Add plasma and thrombin to form a small pellet

Fix in formalin and then process / embed / cut as per FFPE block

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2
Q

Trouble shoot Histo / Cyto Discordance

A

1) Double check patient ID and clinical details (right specimen, right patient?)
2) Levels on histology, review original cytology

3) Still discordant?
- discuss at MDM
- consider lesion elsewhere in gynae / GI / GU tract
- repeat biopsy

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3
Q

DDx Unilateral Pleural Effusion

A

NON NEOPLASTIC

  • infection eg. bacterial pneumonia, TB
  • PE
  • LVF
  • Cirrhosis
  • Autoimmune / CTD - RA / SLE

NEOPLASTIC

  • Mesothelioma
  • Lung carcinoma
  • Pleural metastases from breast, ovary, GI tract
  • Lymphoma (primary e.g. PEL or secondary)
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4
Q

Adeno versus Meso Panel

A

Adeno (Epithelial):
MOC31, BerEp4, claudin 4

Meso:
WT1, calretinin, D240
BAP1 lost
Homozygous deletion of p16 / CDKN2A by FISH

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5
Q

Explain how you would report this urine cyto using the Paris system

A

Standardised reporting system based on cytomorphology that stratifies urine specimens into risk groups

  • NHGUC
  • LGUN (TPS 2.0)
  • AUC
  • SHGUC
  • HGUC

Key point in decision tree = N:C ratio >0.5

Additional features: hyperchromasia, coarse chromatin and irregular nuclear membranes

2 features plus N:C ratio >0.7 - SHGUC or HGUS depending on quantity / number of cells

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6
Q

Reasons for False Negative Results in Cytology

A

False negative = wrongly stating a disease is absent

(Can divide into specimen problems and pathologist problems)

1) Sampling error

2) Obscuring artefact (blood, inflammation, air drying)

3) Poor preservation of cells / degenerate cells

4) Scarcity of neoplastic cells

5) Misinterpretation / misclassification

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7
Q

Reasons for False Positive Results in Urine Cytology

A

False positive= wrongly stating a disease is present when it’s not(

(think of benign mimics)

1) Reactive atypia: bladder stones, IDC, chemo / rads

2) Viral cytopathic effect: BK virus

3) Contaminant cells: upper GU tract, gynae tract, via ileal conduit

4) Not urothelial carcinoma!

  • other primary bladder: SCC, adeno, SCNEC, paraganglioma
  • secondary epithelial: metastasis from breast, prostate, GI, gynae
  • non epithelial tumours: melanoma, lymphoma
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8
Q

Causes of False Positives in Thyroid FNA

A

False positive = stating a disease is present when it’s not

(Think of benign mimics)

1) Inflammation - thyroiditis

2) Hyperplasia - nodular / MNG

3) Benign neoplasms - follicular adenoma, NIFTP, HTT

4) Not thyroid! : parathyroid gland

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9
Q

Causes for False Positives in Effusion Cytology

A

False Positive = stating a disease is present when it’s not

(Think benign mimics)

1) Misinterpretation of cytologic artefacts from specimen collection and preparation - degenerative nuclear features (hyperchromasia, cytoplasmic vacuolation)

2) Reactive mesothelial cells

3) Mullerian inclusions / endosalpingiosis (peritoneum)

3) Unexpected / unusual findings e.g lymphoma, megakaryocytes from bleeding

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10
Q

How is a Papinicolau stain performed?

A

Papanicolau stain is a modified H&E stain which is most useful for identifiying nuclear features in cells.

  1. Fix with Ethanol.
  2. Nuclear stain = Alum Haematoxylin
  3. Cytoplasmic stain = mix of two stains Orange G (good for keratin) and Eosin Azure (mix of three dyes)
  4. Dehydration, clearing, mounting
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11
Q

How do you perform a DQ stain?

A

The DQ or “Diff Quik” stain is a commerical Rominowsky stain variant used to rapidly stain and differentiate cytology specimens.

  1. Air dry and fix with ethanol / methanol
  2. DQ I (pink) = Eosin Y, xanthene + ph Buffer
  3. DQ II (blue) = Thiazine, methylene blue, azure + pH buffer
  4. Rinse and admire!
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12
Q

How do you assess adequacy in LBC?

A

Adequacy = 5000 well preserved and well visualised cells or diagnostic material.

Look at 10 x 40x fields - should have 5 - 10 cells in each.

In NZ: Two LBC systems - Surepath and Thin Prep. Similar principles but slightly different technology / process for each.

ThinPrep gives bigger, thinner circle of cells.

SurePath gives a small, dense circle of cells.

Basic process = cervibroom -> vial with fixative 56 or 24% ethanol.

Vial put into machine (may get agitated), fluid extracted via a filter or via gravitation sediment then cells concentrated and deposited on slide.

Can do HPV genotyping on vial contents (and make a cell block).

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13
Q

Role of HPV testing in NZ

A

The NZ Cervical Screening Programme is planned to become HPV first in July 2023. At moment hrHPV testing is performed on squamous lesions for:

1. Triage of ASCUS / LSIL in people over age of 30

  • if no abnormal smear in past 5 years and over 30
  • hrHPV subtype present - go to colp
  • hrHPV subtype absent - repeat cytology in 12 months

2. Test of Cure after Treatment for HSIL

  • paired testing with cyto and hrHPV on 2 occasions, 12 months apart

3. On Specialist request after discordant results

  • usually requested at time of colposcopy due to discrepancies in histo, cyto and colposcopy findings
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14
Q

Bethesda System for Thyroid Cytology

A

Standardised tiered reporting system that ensures unambiguous communication to clinician re: the ROM and what next management steps should be.

Always need to interpret cytology findings in clinical and radiologic context.

I - Non - Diagnostic

  • virtually acellular specimens

II- Benign

  • benign follicular nodule, lymphocytic thyroiditis, subacute thyroiditis

III - Atypia of Uncertain Significant (or FLUS)

  • lots of criteria but not to be used as a wastebasket…

IV - Follicular Neoplasm (Suspicious for Follicular Neoplasm)

  • specify if oncocytic type

V - Suspicious for Malignancy

  • specify if PTC, medullary, lymphoma, metastasis

VI - Malignant

  • specify if PTC, PDTC, anaplastic thyroid carcinoma, medullary, metastatic, NHL
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15
Q

Breast FNA Diagnostic Categories

A

C1 Inadequate

C2 Benign

C3 Atypia uncertain significance

C4 Suspicious for malignancy

C5 Malignant

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16
Q

False Negatives in Breast FNA

A

False negative = missing a diagnosis when it is actually present

Specimen Issues

  • target lesion not sampled or undersampled
  • obscuring artefacts (blood, air drying, US gel, inflammatory cells)
  • minimal / scant diagnostic material on slide

Pathologist Issues

  • Mistinterpretation / under and overcalling
  • Well differentiated tumour with miminal atypia
  • Invasive lobular carcinoma mimics histiocytes and lymphocytes
  • Failure to correlate with clinical or radiologic findings
17
Q

False Positives in Breast FNA

A

False positive = diagnosing or calling malignant when not

  • failure to correlate with clinical or radiologic findings
  • difficult / impossible to separate papillary lesions on cytology
  • difficult / impossible to distinguish DCIS from IBC
  • difficult / impossible to separate LGDCIS / ADH
  • overinterpreting pregnancy related changes, fibrocystic changes
18
Q

Milan System for Salivary Gland Cytopathology

A

Evidence based, standardised, tiered reporting system for salivary gland cytology.

Allows clear communication between clinicians with a focus on risk stratification.

Six diagnostic categories, one non-diagnostic category. Primary salivary gland tumours plus others.

I - Non Diagnostic

  • insufficient material for diagnosis, having processed and examined everything
  • exceptions: matrix material and mucinous cyst content

II - Non Neoplastic

  • Inflammatory, metaplastic and reactive changes e.g. chronic sialadenitis, reactive lymph node, granulomas

III - Atypia of Uncertain Significance

  • Neoplasm cannot be excluded, most will represent reactive atypia or undersampled neoplasm

IV - Neoplasm

IVA - Benign neoplasm: eg. PA, WArthins, lipoma

IVB - SUMP: where a malignant neoplasm cannot be excluded. Most will be cellular benign neoplasms, neoplasms with atypical features and low grade carcinomas

V - Suspicious for Malignancy

  • suggestive but non-diagnostic of malignancy. Should state what type of tumour is suspected or provide a list of differential diagnoses, e.g basaloid neoplasms, oncocytic neoplasms etc.

VI - Malignant

  • try to classify / subclassify into type and grade of carcinoma
  • includes other neoplasms such as lymphoma, metastases, sarcomas
19
Q

Types of Respiratory Cytology Specimens

A

Sputum specimen

Bronchiolar lavage, washings and brushings

Pleural fluid

FNA of lesion or lymph node via EBUS

20
Q

False Positives in Respiratory Cytology

A

Common Benign Mimics:

Reactive and reparative changes (infection / inflammation, post chemo / radiotherapy. Meso’s and bronchial cells esp.)

Squamous metaplasia and atypia (esp. next to abscess cavity / aspergilloma)

Degenerative histiocytes

Pink cytoplasm can be artefactual (don’t mistake for keratin)

21
Q

False Negatives in Respiratory Cytology

A

Sampling issues

Poor specimen preparation /