Neoplasia 1 Flashcards
(42 cards)
What is a neoplasm
-what do cells undergo when there is a neoplasm?
A new growth
-tumours, cancer
-undergo irreversible genetic change; become unresponsive to normal growth controls
Oncology meaning
Study of neoplasia
Is a lump always a tumour?
No, can be abscess or puss instead
What is a hamartoma
Disorganised tissue but in the correct site (it is where it should be)
-normal
-normal tissue chaotically arranged
What is choristoma
Tissue chaotically arranged but in the wrong site
Example of choristoma
Dermoid; haired skin on cornea (eye)
What are the 4 preneoplastic changes that can occur before neoplasia does?
Hypertrophy
Hyperplasia
Metaplasia
Dysplasia
Are preneoplastic changes reversible?
Yes, can regress
Most tumours are a ________ population i.e;
Monoclonal; one cell type
What are the 3 basic cell populations that can produce tumour cells
Mesenchymal (come from mesoderm)
-CT, fat, cartilage
-muscle
Round cell tumours
-subgroup of mesenchymal, come from mesoderm
Epithelial (come from ectoderm, mesoderm, endoderm)
-ecto; covering epithelium e.g skin
-meso; solid organs eg renal tubules, hepatocytes
-endo; lining epithelium e.g gut
Leukaemia are malignancies derived from;
circulating blood cells or their precursors
what is nomenclature
Treatment prognosis which tells you cell of origin and tells us whether cells are benign or malignant
Describe the nomenclature for mesenchymal tumours
On anki cards
Malignant versus benign tumours
Malignant; spread rapidly, cancerous, invade and destroy normal tissue
Benign; grow slowly and don’t spread, non cancerous
Describe the nomenclature for epithelial tumours
On anki cards
Histologically,
Mesenchymal cells tend to form…
Epithelial cells tend to form…
(Disorganised) sheets
Specific structures
Which 4 important features can we look at to tell whether a tumour is malignant or benign?
- Differentiation
- Rate of growth
- Local invasion
- Metastitis
- Differentiation feature of tumours
Normal differentiated cells are easily distinguishable due to their features e.g squamous epithelial cells. There is little variation between individuals
Neoplastic cells on the other hand lose these differentiated features i.e dedifferenciate. With loss of Morphological features there is also a loss of functional capacity & there is a development of aggressive behaviour
2 types of stem cells and what each does
Totipotent; can regenerate all tissues of body
multipotent/pluripotent; give rise to smaller variety of tissue types
Most adult stem cells have __________ plasticity
Limited (don’t have totipotiness)
Tumours are made up of cells that lack what?
Fully differentiated features
Anaplastic meaning
cells which have would dedifferentiated to the point that you cannot tell which cell it used to be
- Rate of growth feature of tumours
Normal versus neoplastic
Normal; cells are quiescent, stable in G0 but can kick back into dividing mode when needed eg hepatocytes in liver
Neoplastic; have little time in G0, don’t undergo cell cycle arrest, don’t get checked for damage, proliferate continuously
What can tumours do apart from continuously dividing non stop?
Inactivate death factor signalling pathways; blocks apoptosis and growth rate increased
Activate survival signalling pathways; become independent to bodies needs, not working on common good for rest of body
