Lab Diagnosis

Question 1

What are the types of tissues that can be sent to the histology lab?

Answer 1

Tissue

• diagnostic biopsy including incisional or needle core
• excisional specimen

Cytology

• exfoliative (scraped or shed cells)
• fine-needle aspiration

Question 2

Examples of cytology samples which are shed? Why is it not great for cancer diagnosis?

Answer 2

Those that fall off a surface

• sputum
• urine
• pleural and ascitic fluids

Cells usually degenerate so cancer pick-up rate is low

Question 3

What is a scrape?
Examples
Good for cancer diagnosis?

Answer 3

From a surface eg

• cervical smear
• bronchial bushings

Yes - they are intact and viable cells so cancer pick-up rate is higher

Question 4

When is an aspirate used? When is image guidance needed?

Answer 4

When there is no surface available eg accessible ku o, breast or lymph node
Can have image guidance to help for inaccessible lumps, the liver or pancreas

Question 5

When processing samples, the tissues a cut up and a macro description is given. What observations does this include?

Answer 5

Tumour size
Appearance
Spread

Question 6

Why might some tissues be inked?

Answer 6

If it is tissue resected during cancer surgery - demonstrates the excisional margin when looking down a microscope

Question 7

What is used to support tissue so it can be cut up to 4μm sections? What happens next?

Answer 7

Impregnated with wax

Mounted on a glass slide and stained

Question 8

What are some problems when trying to diagnose cancers?

Answer 8

Can be difficult to tell if some cases are malignant or benign - on a spectrum

Question 9

What aspects are normally considered in a histology report?

Answer 9

Lesion present?
Is it malignant?
Type of malignancy?
Grade
Stage (spread)
Is it all out?

Question 10

What are the tissue changes that indicate a tumour is malignant?

Answer 10

Dysplasia
Invasio
Infiltrative margin

Question 11

What cytological changes indicate that a tumour is malignant?

Answer 11

Nuclear pleomorphism - size, shape and staining
Increased proliferation
Abnormal mitotic figures

Question 12

What are the different histogenic classifications of tumours?

Answer 12

Differentiation

• squamous
• glandular
• lymphoid
• melanocytic

Molecular classification may be more useful in the future eg BRAF mutation

Question 13

What are the different considerations when considering the type of malignancy?

Answer 13

The differentiation/histogenic class
Architectural arrangements eg glands
Cytological differentiation

Question 14

What are the cytological differentiations considered?

Answer 14

Morphology eg desmosomes, mucin, melanin

Protein expression - lymphocyte differentiation pathogens

Question 15

What aspects are looked at in protein expression?

Answer 15

Filaments - are they low or high molecular weight cytokeratins
Specific protein produces eg thyroglobulin
Enzyme production

Question 16

What is the gold standard for cancer diagnosis?

Answer 16

Histology

Question 17

What is assessment of grade based on?

Answer 17

Proliferation
Architectural differentiation
Pleomorphism

Question 18

What is grade used for?

Answer 18

Prognostication

Management

Question 19

What is stage used for?

Answer 19

Predictor of prognosis and management

Question 20

Where do carcinomas and sarcomas spread to/via?

Answer 20

Carcinomas - to lymph nodes

Sarcomas - via blood stream

Question 21

What does TNM stand for in staging?

Answer 21

Tumour
Nodes
Metastasis

Question 22

What is wrong with axillary clearance in treating breast cancer?

Answer 22

Has significant morbidity due to lymphoedema

Question 23

What cancers is sentinel lymph node biopsy commonly used for?

Answer 23

Breast
Melanoma
Penile squamous cell carcinoma
Head and neck squamous cell carcinoma

Question 24

How is sentinel lymph node biopsy done?

Answer 24

Inject a dye and short half-life isotope
Tumour will reach the first lymph node in the draining site first
Therefore if the lymph node is negative of dye, the patient does not need clearance as it has not spread to the lymph node

Question 25

What is done in Moh’s micrographic surgery?

Answer 25

A layer of skin is removed each time and assessed under a microscope there and then. Allows for close examination of skin to look for cancer cells

Question 26

What are some ancillary techniques (supportive) to aid in diagnosis?

Answer 26

Histochemical stains to characterise tissue components such as collagen and melanin
Electron microscopy 
PCR 
In situ hybridisation
Cytogenetics - detect translocations

Question 27

What is PCR used for in cancer diagnosis?

Answer 27

Assess monoclonality

See if there is an infection eg HHV8 in Kaposi’s sarcoma

Question 28

How is immunohistochemistry done?

Answer 28

Antibodies bind to specific proteins in tissues
Antibodies are applied to tissue sections and detected via a colour-producing peroxidase reaction
Antigens of interest can be injected into animals to stimulate an immune response

Question 29

Give some examples of biological markers which can help to determine therapy

Answer 29

Steroid receptors - tamoxifen
HER-2 - Herceptin
C-KIT expression - imatinib
CD-20 expression - rituximab

Question 30

How does oestrogen affect growth of some tumours?

Answer 30

Can regular genes that promote growth

Question 31

Which receptor family is HER-2 a member of?

Answer 31

The EGF receptor family

Question 32

What can in situ hybridisation be used for?

Answer 32

Assessment of clonality in B cell lymphoid neoplasms via kappa and lambda light chain expression

Detection of EBV in EBV-encoded RNA

Identification of tumour-specific translocations

Question 33

What type of receptor is HER-2?

Answer 33

A member of the EGFR family

It is a tyrosine kinase which promotes cell growth

Question 34

What are the core members of an MDT who discuss the results of histology?

Answer 34

Surgeon
Radiologist
Oncologist
Histopathologist

Question 35

What information is presented at MDT meetings?

Answer 35

Clinical, pathological and radiological information