MOD S10 - Neoplasia II

Question 0

Define metastasis

Answer 0

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

Question 1

Define invasion

Answer 1

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

Question 2

What are the mechanisms facilitating cell invasion and metastasis

Answer 2

Altered cell adhesion
Altered enzyme synthesis and interaction
Angiogenesis

Question 3

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

Answer 3

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

Question 4

Describe how altered enzyme synthesis and interaction facilitates invasion and metastasis

Answer 4

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

Question 5

Give specific examples of matrix metalloproteinases

Answer 5

MMP1 acts on type I collagen

MMP2/9 acts on type IV collagen

Question 6

Describe how angiogenesis facilitates invasion and metastasis of cells

Answer 6

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

Question 7

What are the common routes of metastasis?

Answer 7

Lymphatics

Vascular

Question 8

Describe metastasis via lymphatics

Answer 8

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

Question 9

Describe metastasis via the vascular system

Answer 9

Spread through capillaries and veins to various organs

Common sites are bone, brain, lung and liver

Question 10

What cancers commonly metastasise to the lung?

Answer 10

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

Question 11

What cancers commonly metastasise to the liver?

Answer 11

Carcinomas eg breast, bronchial, large intestine

Very common from the large intestine as the metastases travel via the portal vein

Question 12

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

Answer 12

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)

Question 13

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

Answer 13

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

Question 14

Describe the local effects of a benign neoplasm

Answer 14

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)

Question 15

Describe the local effects of malignant neoplasms

Answer 15

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

Question 16

Describe the systemic haematological effects of a neoplasm

Answer 16

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

Question 17

Describe the systemic endocrine effects of neoplasia

Answer 17

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

Question 18

Describe the systemic skin effects if neoplasia

Answer 18

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

Question 19

Describe the systemic neuromuscular effects of neoplasia

Answer 19

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

Question 20

Define cachexia

Answer 20

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

Question 21

Define malaise

Answer 21

A general discomfort or uneasiness

Question 22

Define pyrexia

Answer 22

Fever

Question 23

How can neoplasms kill?

Answer 23

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