Pathology Flashcards
What three factors could cause thrombosis?
- Change in vessel wall
- Change in blood flow
- Change in blood constituents
Define a Carcinoma In Situ
A malignant epithelial neoplasm that hasn’t invaded the original basement membrane
Define an Invasive Carcinoma
A carcinoma that has breached the basement membrane and is now free to spread elsewhere
Define a Micro-Invasive Carcinoma
A carcinoma that has breached the basement membrane BUT hasn’t invaded far from original carcinoma
Invasion of malignant neoplastic cells - what 3 factors is it dependant on?
- Decreased cellular adhesion
- Abnormal cellular motility
- Production of enzymes that have a lytic effect on surrounding tissues
What does invasion of neoplastic cells allow?
The cells to spread through tissue and gain access to blood vessels and lymphatic channels
Define metastasis
The process by which a malignant tumour spreads from its primary site to produce secondary tumours at a distant site.
Metastasis can occur through (5) …
- Blood vessels
- Lymphatics
- Across Body cavities
- Along nerves
- Through direct implantation of neoplastic cells during a surgical procedure
What are the 7 stages of the Metastasis cascade?
Detachment
Invasion
Intravasation
Survival in circulation
Arrest
Extravasation
Colonisation
What occurs during Invasion (Metastasis Cascade)?
Invading through the basement membrane
What occurs in Intravasation (Metastasis Cascade)?
Collagenases and Cell motility
What occurs during the Survival in Circulation (Mestastasis Cascade)?
Aggregation with platelets
Shedding of surface antigens
Adhesion to other tumour cells
What occurs during Extravasation (Metastasis Cascade)?
Adhesion Receptors
Collagenases
Cell motility
Growth at the metastatic site occurs using…
Autocrine growth factors
Name the process of a tumour growing its own blood vessels
Angiogenesis
At what diameter does angiogenesis occur?
1mm
What are some angiogenesis promoters?
Vascular endothelial growth factors
Basic fibroblast growth factors
What are some Angiogenesis inhibitors?
Angiostatin, endostatin, vasculostatin
What are the routes of metastasis?
- Can invade arterial side if grows large enough and breaks off
- Haematogenous (via blood stream)
- Lymphatic (lymph channels)
- Trans-coelomic (pericardial and peritoneal cavities)
Describe the haematogenous route of metastasis
Forms secondary tumours in organs perfused by blood that’s drained from a tumour
Describe the lymphatic route of metastasis
Forms secondary tumours in regional lymph nodes
What does the Trans-Coelomic route of metastasis result in?
Invariably results in neoplastic effusion
Which tumours commonly metastasise to the lung?
Sarcomas and any common cancers
Which tumours commonly metastasise to the liver?
Colon, stomach, pancreas and carcinoid tumour of the intestine