W5 Lecture 4: the spread of milignant tumours

Question 1

types of spread in malignant tumours?

Answer 1

local spread
Distant/ Disseminated spread

Question 2

local spread??

Answer 2

-Direct invasion and infiltration between tissues
- Tissue planes
- Bone, cartilage and fascia are more resistant to direct invasion
- Invasion of body surfaces e.g. ulceration of mucosa or skin
- Fixed to underlying tissue or skin e.g. CA of breast can ulcerate through skin or be
fixed to fascia and/or skeletal muscle.
- Histology: confirms tumour invasion microscopically
- Tumour cells destroy the cellular basement membrane and invade into adjacent
tissue

Question 3

distant spread

Answer 3

-METASTASIS
- Tumour cells become detached from main tumour mass and spread to a distant
site forming a secondary mass of tumour
- METHODS OF DISTANT SPREAD:
1) LYPHATIC VESSELS
2) BLOOD VESSELS
3) BODY CAVITIES
4) IMPLANTATION

Question 4

lymphatic spread

Answer 4

CARCINOMAS
Early spread
Gain access through local invasion of lymphatics
LYMPHATIC CHANNELS: (a) EMBOLISE (detach)
(b) PERMEATION (continuous growth
along lymphatic channel)

Question 5

outline the emboli??

Answer 5

-Travel in normal direction of lymph flow
- Spread to regional lymph nodes
- Perinodal soft tissue spread beyond nodal capsule
- Spread via lymphatic efferent vessels to reach central/distant
nodes
- Retrograde embolism: occurs when onward flowing
lymphatics are blocked

Question 6

hematogenous spread

Answer 6

-SARCOMAS
-After lymphatic spread in carcinomas
-Direct venous invasion
-Arterial invasion rare (except in lung)
- COMMON SITES for blood borne metastasis
- LUNG: tumour invades systemic veins and traverses right side of heart
- LIVER: tumour form emboli in the portal venous system and impact in the portal
hepatic capillary system
-BRAIN
-BONE / SPINE
-ADRENAL GLAND

Question 7

lymphatic permeation

Answer 7

Tumour cells grow and infiltrate along lymphatic channels in a
solid cord
-Blockage of lymphatic channels can cause lymphedema
- Peaud’orange: skin of breast with lymphatic permeation
Other:
-Perineural spread
- Infiltration along nerve sheaths

Question 8

what is the process of metastatic spread?

Answer 8

-Actual invasion and penetration into vessels
- Cell motility
-Tumour expresses receptors which bind to proteins of the basement membrane and
extracellular matrix
-Tumour secretes proteolytic enzymes ( Collagenases) which destroy the extracellular
matrix
- Tumour cells must survive
- Adherence to platelets (PDGF) and endothelial surface
- Proliferation of tumour (ability to replicate)
- Angiogenesis (new vessel formation)
- Oncogene expression (promotes metastasis)
- Evade immune response: NK cells, macrophages, cytotoxic T-lymphocytes

Question 9

How do the ovarien tumours spread?

Answer 9

pertitoneal seeding