Lecture 9.1: Invasion & Metastasis and the Effects of Neoplasms

Question 1

What is a Neoplasm?

Answer 1

An abnormal growth of cells that persists after the initial stimulus is removed

Question 2

What is a Malignant Neoplasm?

Answer 2

An abnormal growth of cells that persists after the initial stimulus is removed and invades surrounding tissue with potential to spread to distant sites

Question 3

What is Neoplasia?

Answer 3

A disorder of cell growth, triggered by a series of mutations (germline, acquired, somatic) affecting a single cell and its clonal progeny

Question 4

What is a Tumour?

Answer 4

• Any clinically detectable lump or swelling
• A neoplasm is just one type of tumour

Question 5

What is Cancer?

Answer 5

• A cancer is any malignant neoplasm

Question 6

What is Metastasis?

Answer 6

• A malignant neoplasm that has spread from its
  original site to a new non-contiguous site
• The original location is the primary site
• The place to which it has spread is a secondary site

Question 7

What is Dysplasia?

Answer 7

• A pre-neoplastic alteration in which cells show
  disordered tissue organisation
• It is not neoplastic because the change is reversible

Question 8

How to Name Neoplasms?

Answer 8

• Benign neoplasms ends in –oma.
• Malignant neoplsams end in –carcinoma: if it is an epithelial malignant
neoplasm (90% malignant tumours)
• – sarcoma if it is a stromal malignant neoplasm

Question 9

What are the 2 types of carcinomas?

Answer 9

• In-situ (no invasion of epithelial basement membrane)
• Invasive (penetrated through basement)

Question 10

What is a Benign Neoplasm of Fibrous Tissue called?

Answer 10

Fibroma

Question 11

What is a Benign Neoplasm of Smooth Muscle called?

Answer 11

Leiomyoma

Question 12

What is a Benign Neoplasm of Striated (Skeletal) Muscle called?

Answer 12

Rhabdomyoma

Question 13

What is a Benign Neoplasm of Bone called?

Answer 13

Osteoma

Question 14

What is a Benign Neoplasm of Cartilage called?

Answer 14

Chondroma

Question 15

What is a Benign Neoplasm of Fat called?

Answer 15

Lipoma

Question 16

What is a Benign Neoplasm of Nerves/Nerve Sheath called?

Answer 16

Neuroma/Neurofibroma

Question 17

What is a Benign Neoplasm of Glial Cells called?

Answer 17

Glioma

Question 18

What is a tumour of glandular tissue called?

Answer 18

Adenocarcinoma/Adenoma

Question 19

What is a Melanoma?

Answer 19

Malignant tumour of cells derived from neural crest

Question 20

What is a Mesothelioma?

Answer 20

Tumour of mesothelium (malignant)

Question 21

What does the suffix -blastoma refer to?

Answer 21

Tumours that arise from precursor cells and are composed of cells with immature characteristics seen in developing (embryonic) stages

Question 22

What is the origin of a Carcinoma?

Answer 22

Refers to a malignant neoplasm of epithelial origin or cancer of the internal or external lining of the body

Question 23

What is the origin of an Adenocarcinoma?

Answer 23

Which develops in an organ or gland

Question 24

What is the origin of a Squamous Cell Carcinoma?

Answer 24

Which originates in the squamous epithelium

Question 25

What is the origin of a Sarcoma?

Answer 25

Sarcoma refers to cancer that originates in supportive and connective tissues such as bones, tendons, cartilage, muscle, and fat

Question 26

What is the origin of a Myeloma?

Answer 26

Originates in the plasma cells of bone marrow

Question 27

What is the origin of a Leukemia?

Answer 27

Cancers of the bone marrow Affect WBCs and RBCs

Question 28

What is the origin of Lymphomas?

Answer 28

Develop in the glands or nodes of the lymphatic system, a network of vessels, nodes, and organs (specifically the spleen, tonsils, and thymus) that purify bodily fluids and produce infection-fighting white blood cells, or lymphocytes

Question 29

Hodgkin Lymphoma vs Non-Hodgkin Lymphoma

Answer 29

The presence of Reed-Sternberg cells in Hodgkin lymphoma diagnostically distinguishes Hodgkin lymphoma from Non-Hodgkin lymphoma

Question 30

Early in female embryogenesis one allele is randomly inactivated in each cell, what is this called?

Answer 30

Lyonisation

Question 31

Main steps involved in invasion of extracellular matrix (4 Steps)

Answer 31

* Detachment of tumour cells from one another by unzipping of the anchor protein E-cadherin * Degradation of the extracellular matrix by collagenase attacking the collagen fibres of the basement membrane * Loss of adhesion of cells from integrins * Migration of tumour cells through the extracellular matrix

Question 32

Stromal invasion involves 5 important alterations

Answer 32

* The cells must degrade basement membrane and stroma to invade * This involves altered expression of proteases, notably matrix metalloproteinases (MMPs) * Malignant cells take advantage of nearby non- neoplastic cells, which together form a cancer niche * These normal cells provide some growth factors and proteases * Altered motility involves changes in the actin cytoskeleton

Question 33

Routes of Metastatic Spread (3)

Answer 33

• Blood • Lymphatic • Transcoelomic (pleura, peritoneum)

Question 34

What are Circulating Tumour Cells (CTCs)?

Answer 34

A rare subset of cells found in the blood of patients with solid tumours, which function as a seed for metastases in the locations in the body

Question 35

How do cancer cells evade destruction in the circulation?

Answer 35

* Release of coagulation factors, resulting in formation of an outer platelet shield and then a tumour platelet microthrombi * This protects from shearing and turbulence forces * Prevents immune detection using platelet derived MHC class I coating

Question 36

What are NK Cells?

Answer 36

They are WBCs, a type of immune cell that has granules (small particles) with enzymes that can self-cells that are presenting abnormal antigens: kill tumour cells or cells infected with a virus

Question 37

What must Malignant Cells do at secondary sites to form a Clinical Metastasis?

Answer 37

* At a secondary site malignant cells must get out of a vessel (extravasation) and then grow * This is a dynamic process including adhesion, vascular migration and endothelial remodelling (Twist gene)

Question 38

What are Micrometastases?

Answer 38

* Many malignant cells lodge at secondary sites * These tiny cell clusters often either die or fail to grow into clinically detectable tumours * Surviving microscopic deposits that do not grow are called micrometastases

Question 39

What is "Tumour Dormancy"?

Answer 39

When a malignant neoplasm relapses years after an apparent cure it is typically due to one or more micrometastases starting to grow