Neoplasia 1 Flashcards
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
What is function of telomerase
-expressed by what cells
Enzyme expressed by stem & germ cells which allows for telomere replication
What happens in normal somatic cells when telomerase is expressed?
On the other hand, what happens in Neoplastic cells
Extreme ends of DNA templates not duplicated
Telomeres that form chromosome ends shortened at each cell division-> cell senescence-> cell death
Neoplastic cells regain ability to produce telomerase;
Allows for more tel more replication, there is no shortening and therefore no cell death
What is the latency period of a solid tumour growth
Period when tumour is not clinically obvious
A tumour takes how many doubling to be visible?
How many doubling more to become a kg in size, which is fatal?
30
10
Important factors in tumour growth
-Blood supply
-Extrinsic growth regulating factors
-Efficacy of host immune response
-Emergence of sub populations of aggressive tumour cells
Characteristics of benign tumours
Well differentiated
Recogniseable structure
Slow progressive expansion
Rare mitosis figures
No true invasion
Often encapsulated
Expansive growth
No metastitis
Characteristics of malignant tumours referring to the 4 features of tumours
Lack of differentiation
Atypical structure
Variable degree of anaplasia
Rapid growth rate
Often lots of mitosis figures
Local invasion present
Infiltrate growth
No capsule
Frequent metastatis
Cause death if untreated!!!
Cytological criteria of Malignancy
Meaning of Anisocytosis and macrocytosis
(Defintion of word split up—>
Aniso=
Macro=
Cyt=)
- Unlike, inequal
- Large
- Cell
Therefore anisocytosis means there is variation in cell size
Macrocytosis means larger cell than normal
anisocytic and macrocytosis cells are features of which type of neoplasia?
Malignant tumour
Hypercellularity meaning
Increased exfoliation of cells from a tissue that doesn’t normally exfoliate easily (due to decreased cell adherence)
Only applied to certain types of tissue
E.g lots of spindle cells found in bone
Pleomorphism meaning
Variation in cell size and shape within a given cell population i.e a non uniform or irregular appearance of cell population
Macrokaryosis meaning
Enlarged nuclear size
Increased nucleus : cytoplasm ratio
An increased amount of nucleus compared to cytoplasm for a given cell type
Doesn’t count for cells that normally have a very high N:C ratio e.g lymphoid cells
Anisokaryosis
Variation in nucleus size
Particularly suggestive of malignancy when it occurs within one cell
Multinucleation meaning
Multiple nuclei within one cell
Increased mitosis figures meaning
A way to identify how vigorous cell dividing is occurring, e.g if there’s lots of mitosis going on, could indicate that cells are neoplastic
What are some exceptions to increased mitosis figures
bone marrow, intestinal crypts
Inflamed or reactive tissue
Generally most are in low numbers
What are the 6 hallmarks of cancer
Sustaining proliferative signalling
Resisting cell death
Evading growth suppressors
Inducing angiogenesis
Activation invasion and metastasis
Enabling replicative immortality
