Pathology in diagnosis and management

Question 1

Why is tumour pathology important?

Answer 1

Useful for clinical presentation, classifying neoplasms and determining treatment options.

Question 2

What are the main gross characteristics of a benign tumour?

Answer 2

Well circumscribed
Smooth
Mobile

Question 3

What the main gross characteristics of a malignant tumour?

Answer 3

Irregular
Poorly defined
Fixed to adjacent tissue

Question 4

What are the two types of breast lumps that can develop?

Answer 4

Fibroadenoma - benign glandular neoplasm in women <30. ‘Breast mice’ due to mobility
Breast carcinoma - Malignant neoplasma and commonest cause of female death. >50yrs mainly. Invades local structures

Question 5

Where do most cases of colon cancer arise and why?

Answer 5

Glandular epithelium = adenocarcinoma.
It is the area exposed to the highest concentration of carcinogens and has a high turnover rate, making it susceptible to mutations.

Question 6

How does cecum or ascending colon cancer present?

Answer 6

Often polypoid and rarely causes obstruction.

Weight loss and anaemia from low grdde blood loss

Question 7

How does sigmoid colon cancer present?

Answer 7

Most common site. Stenosing and causes bowel obstruction.

Altered bowel habit, constipation due to hard stool and narrow lumen or diarrhoea as only watery stool passes through.

Question 8

What specimens can be obtained from a neoplasm and how are they obtained?

Answer 8

Biopsy - small piece of tissue from endoscopy or needle / punch biopsy
Cytology specimens - individual or small group of cells from smears, brushing, fluids, FNA
Surgical resection

Question 9

Why are specimens needed?

Answer 9

To confirm diagnosis and identify histology type to plan future treatment.
A surgical resection can be used to see if the resection had good margins.

Question 10

What is offered to a Pt if metastasis is established?

Answer 10

No surgery

Chemo or radiotherapy

Question 11

What are the limitations of biopsies?

Answer 11

Tumours are heterogenous and have varying appearances in different parts so may not select all types.
Targeting the lesion may be difficult do to size or accessibility or near vulnerable/dangerous structures.

Question 12

Why can pancreatic cancer not be biopsied?

Answer 12

Because there is a surrounding stromal reaction occurring at the site, would lead to rapid deterioration and seeding.

Question 13

What are the advantages and disadvantages of cytology specimens?

Answer 13

Obtained via less invasive methods e.g. cystoscopy and FNA uses a thinner needle than biopsy.
Provides access to sites not suitable for biopsy due to thin needle.
Smaller tissue samples but may make interpretation more difficult

Question 14

Why might a surgical resection be used?

Answer 14

With the aim to cure.
Also used in pallative treatment to reduce symptoms.
To determine if further treatment is required and if good margins.

Question 15

What does a resection confirm?

Answer 15

The diagnosis
Aggressiveness and grade of tumour
Extent of spread = staging and node involvement
Resection margins
necrosis or haemorrhage
Micro and macro - shape, size, histology, origin

Question 16

What does staging show?

Answer 16

The extent of spread and therefor determines prognosis.

Question 17

Name three types of staging.

Answer 17

TNM
Duke’s system for colorectal
Breast cancer uses T1-T4 for description of invasion into chest wall

Question 18

What increases the stage of cancer if present?

Answer 18

Capsular or vascular invasion

Question 19

What data must be included in a histopathology report?

Answer 19

Prognostic information
Data for cancer registration
Quality of resection feedback
Adjuvant therapy decision
Evealuate effectiveness of neoadjuvant therapy

Question 20

What is immunohistochemistry?

Answer 20

A fluorescently labelled Ig used to identify an Ig bound to an antigen of a cell.

Question 21

How is immunohistochemistry used to estabilish malignancy ?

Answer 21

Reactive inflammatory infiltrates will have a mixed population of mostly T and some B cells.
Neoplastic infiltrates with have a PURE population of cells, composed of B cells, showing clonal population

Question 22

How is immunohistochemistry used as a prognostic marker?

Answer 22

Show cell turnover

Determines the metastatic potential and grade

Question 23

How is immunohistochemistry used to identify theraputic options?

Answer 23

The expression of a specific antigen marker will identify if the tumour is likely to respond to specific targeting therapies that target these antigens.
e.g. HER2 in breast cancer = Herceptin
Oestrogen R in breast = Hormonal Tx

Question 24

What is in-situ hybridisation?

Answer 24

A molecular technique that uses probes to recognise specific DNA sequences within tissue sections. Can test for kappa and lamda chains for the presence of plasma cell infiltrates for reactive v neoplastic.
EBV is encoded into RNA

Question 25

What is post-transplant lymphoproliferative disease and what causes it?

Answer 25

An abnormal lymphoid proliferation when immunosuppressed. May be due to polyclonal lymphoid hyerplasia or monoclonal malignant lymphoma.

Question 26

Which virus is mostly associated with PTLD?

Answer 26

EBV - Virus infects B cells and remains latent under control of T cell response but when imunnosuppressed T cell function is reduced and EBV proliferation within B cells occurs.

Question 27

How does PTLD present?

Answer 27

Within 12 months post-transplant with focal masses or diffuse infiltrates.

Question 28

How can extracted RNA or DNA be used in diagnosis?

Answer 28

Can identify Ig gene rearrangments ot TCR rearrangement to demonstrate clonality in B and T cell neoplasms. Determines gene mutations and the treatment options.

Question 29

Why is a MDT needed?

Answer 29

To make decisions regarding diagnosis, treatment etc using the specialist knowledge from a variety of different HCP.