Pathology -carcinogenesis ; Cancer

Question 1

What is carcinogenesis?

Answer 1

Transformation of normal to neoplastic cells through permanent mutation

Question 2

What 3 things describe a neoplasm?

Answer 2

Autonomous, abnormal, persistent new growth

Question 3

What can a neoplasm only arise from?

Answer 3

A nucleated cell
Can’t arise from erythrocytes but can from their precursor (erythroblasts)

Question 4

What is a tumour?

Answer 4

Any abnormal swelling
Eg, neoplasm, inflammation, hypertrophy, hyperplasia

Question 5

What do solid tumours consist of ?

Answer 5

Neoplastic cells and stroma

Question 6

What are 2 ways tumours are classified by?

Answer 6

Behaviour (benign or malignant)
Histogenesis

Question 7

Benign vs malignant
Invading?
Rate of growth?
Spread?
Differentiation?

Answer 7

Benign:
Localized (No BM invasion)
Slow growing (little mitosis figures)
Well circumcised
Exophytic (outward growth)
Encapsulated
Rare ulceration & necrosis
Close resemblance to normal tissue
Non invasive (doesn’t spread)

Malignant:
BM invading
Very fast mitosis growth (hyper dense nuclei) -stain dark
Invasive - form metastases
Endophytic - inward growth
Common necrosis & ulceration
Poorly differentiated (little resemblance to normal tissue)

Question 8

How can benign structures still be pathological?

Answer 8

Pressure on local structures - pituitary chiasm
Obstruction
Production of hormones (prolactinoma)
Transformation —> malignant
Anxiety and stress

Question 9

What is histogenesis?

Answer 9

Origin cell of tumour

Question 10

Epithelial cells:what are they called?
Non glandular benign
Non glandular malignant
Glandular benign
Glandular malignant

Answer 10

Papilloma
Carcinoma
Adenoma
Adenocarcinoma

Question 11

Connective tissue (sarcoma) : benign & malignant
Adipocytes
Muscle (striated)
Muscle (smooth)
Cartilage
Bone

Answer 11

Lipoma, liposarcoma
Rhabdomyoma, rhabdomyosarcoma
Leiomyoma, leiomyosarcoma
Chondroma, chondrosarcoma
Osteoma, osteosarcoma

Question 12

Lymphoid:
What are they always?

Answer 12

Leukemia
Lymphoma
(Always malignant)

Question 13

A basal cell carcinoma…

Answer 13

Never metastasize

Question 14

What are:
Melanomas
Mesotheliomas
Teratoma

Answer 14

Melanocyte malignancy
Mesothelial malignancy-typically pleural
Cancer of all 3 embryonic germ layers

Question 15

What are these 3 ?
Burkitt’s lymphoma
Kaposi sarcoma
Ewing sarcoma

Answer 15

B cell malignancy caused by EBV
Vascular endothelial malignancy, HIV associated
A bone malignancy

Question 16

Tumours are graded based on?

Answer 16

Similarity to parent cell

Question 17

how are the tumours graded based on similarity to parent cell?

Answer 17

1. Well differentiated (>75% cells resemble parent)
2. 10-75%
3. Poorly differentiated (<10% cells resemble parent)

Question 18

4 Characteristics of the neoplastic cell?

Answer 18

Autocrine growth stimulation - over expression of growth factor and mutation of tumour suppressor genes eg. P53 and under expression of growth inhibitors

Evasion of apoptosis

Telomerase; prevents telomeres shortening with each replication (this normally rate limits the extent of mitosis a single cell can undergo)

Sustained angiogenesis + ability to invade BM

Question 19

Classes of carcinogens (cancer causing agents) & examples

Answer 19

Chemical - eg. Paints, dyes, rubber, soot
Viruses - EBV (burkitt’s), HPV (cervical cancer)
Ionizing + non ionizing radiation - UVB in skin cancer
Hormones, parasites, mycotoxins- eg, increased oestrogen implicated in breast cancer
MISC - eg, asbestos

Question 20

Pathways of metastasis (5 steps)

Answer 20

1. Detachment (from 1^ )
2. Invasion of other tissue
3. Invasion of BV
4. Evasion of host defense, adherence to BV wall
5. Extravasation to distant site

Question 21

What are the 3 methods of spread?

Answer 21

Haematogenous

Lymphatic

Transcolemic

Question 22

What is haematogenous spread?
Key point?

Answer 22

Via blood (go to bone,breast, lung, liver)

KEY POINT: 5 main metastasis to bone = BLT KP
Breast, Lung, Thyroid, Kidney, Prostate

Question 23

What is lymphatic spread?

Answer 23

2^ formation in lymph nodes
Eg. Lymphoma (rubbery lymphadenopathy)

Question 24

What is transcolemic spread?

Answer 24

Via exudative fluid accumulation, spread through pleural, pericardial + peritoneal effusions

Question 25

How are sarcomas and carcinomas mostly spread?

Answer 25

Sarcomas - mostly haematogenous
Carcinoma- mostly lymphatic

Question 26

What are exceptions to how carcinomas are spread?

Answer 26

Follicular thyroid
Chanocarcinoma
RCC
HCC
ft CRH

Question 27

How are tumours staged?

Answer 27

Mostly TNM
Tumour, node, metastasis

Question 28

What is tumour staging different for?
Eg?

Answer 28

Leukemias, lymphomas, CNS cancers
Eg. Lymphoma - ANN ARBOUR 1-4, A or B

Question 29

What are the 2 mutations involved in colorectal cancer called?

Answer 29

FAP (familial adenomatous polyposis)

HNPCC (lynch syndrome)

Question 30

What is FAP (familial adenomatous polyposis)?

Answer 30

Autosomal dominant gene, mutated, APC gene (adenomatous polyposis coli)
Millions of colorectal adenomas
Inevitable adenocarcinoma by 35 y/o

Question 31

What is HNPCC? (Lynch syndrome)

Answer 31

Mutated MSH gene, autosomal dominant
This genes involved in DNA mismatch repair

Question 32

What is screening?
What type of screening is cancer screening?

Answer 32

Method of early detection
2^ prevention , making management easy

Question 33

Which 3 cancers are screened for in the UK and how?

Answer 33

Cervical (cervical swab)
Breast (mammogram)
Colorectal (fecal occult - fecal immuno histochemical test)

Question 34

What test is done at birth and what does it test for?

Answer 34

Heel prick test at birth for sickle cell, CF, hypothyroid