Session 10: Neoplasia II

Question 1

definitions of invasion, metastasis and cachexia

Answer 1

Invasion: ability of cells to break through the BM and spread

Metastasis: spread of malignant tumour to a distant (ie. non adjacent) site

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

Question 2

describe mechanisms facilitating invasion and metastasis

Answer 2

1 Altered cell adhesions: a) decreased expression of cadherins means less cell to cell contact to cells can move apart and b) dec. expression of integrins means less cell to stroma contact so allows cell movement

2 Secretion of proteases: matrix metalloproteins digest collagen allowing metastatic cells to digest ECM and break through the BM

3 Angiogenesis: at 1-2mm³ tumours become inhibited in their growth by a lack of nutrients and O₂, this alters the microenvironment to become hypoxic -> upregulation of pro-angiogenic factors eg VEGF -> growth of new, thin wall blood vessels leading to continual tumour growth and providing another oppurtunity for the tumour to enter the bloodstream

Question 3

routes and common sites of maetastasis

Answer 3

1 Lymphatics: local and distal, route used frequently by carcinomas, can involve Lung lymphatics

2 Vascular: a) Liver: common site for carcinomas of LI, also bronchial and breast carcinomas

b) Lungs: sarcomas (eg osteosarcoma), carcinomas (eg stomach, breast, LI), kidneys (eg cannonballs - 1 or more large -eg 5cm- well circumscribed metastatic nodules), testes (eg malignant teratoma)
c) Bone: destruction can lead to a pathological frx, commonly from carcinomas like breast, renal, or dense bone formation can occur leading to osteosclerosis eg from prostate cancers
d) Brain: wide range of neurological symptoms, acts as a SOL (space occupying legion), commonly from bronchial, breast or testicular carcinoma or malignant melanoma

3 Coelomic: coelom is the fluid-filled cavity between intestines and the body wall, transcoelomic spread of metastases is predictably to other cells in coelomic space/adjacent organs

Question 4

Comparison of local effects of benign and malignant neoplasms

Answer 4

Benign: -compression -> pressure atrophy, altered function eg in pituitary gland

• in hollow organ -> partial/complete obstruction
• ulceration of surface mucosa
• Space Occupying Lesion in brain

Malignant: -tends to destroy surrounding tissue

• partial/complete obstruction of hollow organ and constriction
• ulceration
• SOL in brain
• infiltration around and into nerves, blood vessels, lymphatics

Question 5

Systemic effects of neoplasms

Answer 5

Haematological: -anaemia from malignant infiltration of bone marrow- leukaemia and metastasis

• dec. WBCs and platelets from infiltration of bone marrow and a consequence of treatment
• thrombosis eg from carcinoma of pancreas

Skin: -inc. pigmentation from many carcinomas

• herpes zoster from lymphoma
• dermatomyositis from bronchial carcinoma
• pruritus (itch) from jaundice, hodgkins

Endocrine: -inc. secretion of hormone eg PTH

-ectopic secretion of hormone eg ACTH by small cell carcinoma of bronchus

Neuromuscular: -myopathy, myasthenia (muscle weakness)

• sensory/sensorimotor neuropathies
• problems w/ balance
• progressive multifocal leucoencepalopathy (progressive damage/inflammation of white matter of brain at multiple locations)

Question 6

haematological systemic effects of neoplasms

Answer 6

• anaemia from malignant infiltration of bone marrow - leukemia and metastasis
• dec. WBCs and platelets from infiltration of bone marrow and a consequence of treatment
• thrombosis eg from carcinoma of pancreas

Question 7

skin systemic effects of neoplasms

Answer 7

• inc. pigmentation from many carcinomas
• herpes zoster from lymphoma
• dermatomyositis from bronchial carcinoma
• pruritis (itch) from jaundice, hodgkins

Question 8

Endocrine systemic effects of neoplasms

Answer 8

• inc. secretion of hormone eg PTH
• ectopic secretion of hormone eg ACTH from small cell carcinoma of bronchus

Question 9

neuromuscular systemic effects of neoplasms

Answer 9

• myopathy, myasthenia (muscle weakness)
• snesnory/sensorimotor neuropathies
• problems w/ balance
• progressive multifocal leucoencethalopathy (progressive damage/inflammation of the white matter of the brain at multiple locations)

Question 10

Lymphatics as a route for metastases

Answer 10

local and distal, route commonly used by carcinomas, can involve lung lymphatics

Question 11

vasculature as a route for metastases

Answer 11

a) liver: common site for metastases of the LI, also bronchial and breast carcinomas
b) Lungs: sarcomas (eg osteosarcoma), carcinomas (eg stomach, breast, LI), kidneys (eg cannonballs - 1 or more large -eg 5cm- well circumscribed metastatic nodules), testes (eg malignant teratoma)
c) Bone: destruction can lead to a pathological frx, commonly from carcinomas like breast, renal, or dense bone formation can occur leading to osteosclerosis eg from prostate cancers
d) Brain: wide range of neurological symptoms, acts as a SOL (space occupying legion), commonly from bronchial, breast or testicular carcinoma or malignant melanoma

Question 12

Coelom as a route for metastases

Answer 12

coelom is the fluid filled cavity between intestines and the body wall, transcoelomic spread of metastases is predictably to other cells in the coelomic space/adjacent organs