MOD S10 - Neoplasia II Flashcards Preview

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Flashcards in MOD S10 - Neoplasia II Deck (24)
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Define invasion

The ability of cells to break through the basement membrane and spread into other tissue


Define metastasis

The spread of a malignant tumour into a distant (aka non-adjacent) site


What are the mechanisms facilitating cell invasion and metastasis

Altered cell adhesion
Altered enzyme synthesis and interaction


Describe how altered cell adhesion assists the invasion and metastasis of cells

Cell to cell interactions: reduced expression of cadherins (which usually bind cells together) allow cells to move apart
Cell to stromatolites interactions: reduced expression of integrins in malignant cells allows movement


Describe how altered enzyme synthesis and interaction facilitates invasion and metastasis

Metastatic cells produce matrix metalloproteinases which digest collagen
This allows the cell to digest the extracellular matrix to reach and break through the basement membrane


Give specific examples of matrix metalloproteinases

MMP1 acts on type I collagen
MMP2/9 acts on type IV collagen


Describe how angiogenesis facilitates invasion and metastasis of cells

Once a tumour reaches 1-2mm cubed, it's growth is halted by lack of nutrients and oxygen
This causes the tumours micro environment to become hypoxic, triggering the up regulation of pro-angiogenesis factors eg angiopoietin, VEGF
This causes the growth of new, thin walled blood vessels, allowing continued tumour growth and providing opportunity for metastasis


What are the common routes of metastasis?



Describe metastasis via lymphatics

Spread to local and distant lymph nodes
Frequent route for carcinoma spread
Can involve lymphatics of the lung


Describe metastasis via the vascular system

Spread through capillaries and veins to various organs
Common sites are bone, brain, lung and liver


What cancers commonly metastasise to the lung?

Sarcomas eg osteosarcoma
Carcinomas eg breast, stomach, large intestine
Testis eg malignant teratoma


What cancers commonly metastasise to the liver?

Carcinomas eg breast, bronchial, large intestine
Very common from the large intestine as the metastases travel via the portal vein


What cancers commonly metastasise to bone and what are the common effects of this?

Carcinoma eg bronchial, breast, renal, thyroid
(These usually cause destruction of bone leading to pathological fractures)
Prostate (can cause production of dense bone aka osteosclerosis)


What cancers commonly metastasise to the brain and what are the common effects?

Carcinoma eg breast, bronchial, testicular
Act as a space-occupying lesion (SOL) and cause a wide range of neurological symptoms


Describe the local effects of a benign neoplasm

Cause compression which can lead to pressure atrophy or altered function (eg in the pituitary)
Can cause complete obstruction in a hollow viscus
Ulceration of surface mucosa
Space occupying lesion (eg brain)


Describe the local effects of malignant neoplasms

Tend to destroy surrounding tissues
Can cause complete obstruction in a narrow viscus
Infiltration into and around nerves, vasculature and lymphatics
Space occupying lesion (eg brain)


Describe the systemic haematological effects of a neoplasm

Anaemia - due to malignant infiltration of bone marrow (leukaemia, metastasis)
Low WBC and platelet count - as a consequence of treatments or infiltration of bone marrow
Thrombosis - seen in carcinoma of the pancreas


Describe the systemic endocrine effects of neoplasia

Excessive secretion of hormones - benign and malignant neoplasms of endocrine glands can produce PTH or corticosteroids
Ectopic hormone secretion - eg ACTH production by bronchial small cell carcinoma


Describe the systemic skin effects if neoplasia

Increased pigmentation - many carcinomas
Pruritis (itching) - jaundice, Hodgkin's disease
Herpes zoster - lymphoma
Dermatomyositis - bronchial carcinoma


Describe the systemic neuromuscular effects of neoplasia

Problems with balance
Sensory/sensorimotor neuropathies
Myopathy and myasthenia
Progressive multifocal leucoencephalopathy
*Not due to metastasis to the brain*


Define cachexia

Loss of weight, muscle atrophy and loss of appetite in someone who is not actively trying to lose weight


Define malaise

A general discomfort or uneasiness


Define pyrexia



How can neoplasms kill?

Locally: raised ICP, perforation, haemorrhage (benign or malignant)
Systemically: replacement of essential body organs eg bone marrow, lung tissue, liver parenchyma (malignant neoplasms)