Neoplasia

Question 1

What id neoplasia?

Answer 1

Autonomous/independent growth of an abnormal cell or tissue, growth of which is more rapid than normal tissues and continues to grow after the stimulus that initiated the new growth is removed

Question 2

What are the prognostic factors in cancer?

Answer 2

Is tumour benign or malignant
Tumour stage:
- carcinoma in-situ
- invasive
- metastatic
Biological characteristics

Question 3

What is dysplasia?

Answer 3

Disorderly growth of epithelium - confined to epithelium
Reversible

Question 4

When does dysplasia turn to neoplasia?

Answer 4

When an entire epithelium is dysplastic and no normal epithelial cells are left, then the process is beyond dysplasia and is now neoplasia

Question 5

What is the histological characteristics of carcinoma in situ?

Answer 5

Entire thickness of the epithelium is replaced by dysplastic cells
No orderly differentiation of squamous cells
The basement membrane is intact, no tumour in the subepithelial stroma

Question 6

What are the histological characteristics of invasive carcinoma?

Answer 6

Neoplastic cells invade the BM

Question 7

What are the differences between benign vs malignant neoplasms? Growth, metastasis, invasiveness, appearance, capsule, cellular shape and size, cell orientation, N:C, Mitoses

Answer 7

Slow, expansive vs fast, invasive
Non-metastatic vs metastatic
Non-invasive vs invasive, destructive
Encapsulated vs crab like
Capsule vs no capsule
Uniform vs pleomorphic
Normal orientation vs disorganised
1:4 vs 1:1
Low mitotic count vs high mitotic count

Question 8

Metastasis

Answer 8

Spread of tumour from primary organ to distant sites in the body
Responsible for 90% deaths in cancer patients

Question 9

What are the stages of metastasis?

Answer 9

Growth and angiogenesis of primary tumour
Local invasion
Penetration of blood vessels or lymphatics - intravasation
Survival in the circulation - CTCs
Arrest and escape from blood vessels or lymphatics - extravasation
-> colonisation and angiogenesis at the new secondary site

Question 10

What are the routes of tumour spread?

Answer 10

Blood vessels
Lymphatic system
Movement within body cavities - peritoneal and pleural

Question 11

What are the different patterns of spread of cancer?

Answer 11

Direct extension
Metastasis
Lymphatic spread

Question 12

What is direct extension as a pattern of spread of cancer?

Answer 12

Binding to ECM
Enzymatic lysis of ECM

Question 13

What is metastasis?

Answer 13

Invasion/penetration of blood/lymph vessel
Release of tumour cells into circulation - CTCs
Arrest of emboli - small vascular channels in distant organs
Growth of tumour in arresting vessels - spread to adjacent tissue
Neovascularisation

Question 14

What is lymphatic spread?

Answer 14

Main forms of spread in early carcinoma
Step wise spread
In transit deposit can occur (melanomas)
Natural routes of drainage - breast to axillary nodes, lung to mediastinal nodes