Cancer Flashcards
What is a cancer?
malignant neoplasm
What are benign cancers?
Cancers which remain localised, do not spread - however can still kill due to their location eg a benign brain tumour could raise intracranial pressure and cause problems
What is the definition of a tumour?
A mass forming lesion of any kind
May be neoplastic or non-neoplastic (hamartomas, inflammatory or heterotopias)
What are neoplasms?
Autonomous growths of tissues which have escaped the normal constraints of cell proliferation
Neoplasms may be either…
benign (remain localised)
or
malignant (invade locally and/or spread to distant sites (aka metastasis)
How do cells become cancerous?
Through the accumulation of mutations through the cell cycle which control the process of cell division
what are malignant tumours?
Those which invade local side/ spreads to distant sites
What are hamartomas?
Localised, benign overgrowths of one or more mature cell types eg lungs - they are tumours, but not neoplasms
What is the main problem associated with hamartomas?
They display architectural abnormalities
Where do hamartomas commonly form?
In the lungs (lung hamartomas are composed of cartilage and bronchial tissue)
What are three types of tumours?
Neoplastic, (hamartomatous or inflammatory)= non-neoplastic
What is a heterotopia?
When normal tissue is found in parts of the body where they are not normally found
A 51-year-old male underwent an endoscopy during colon screening. An erythematous flat lesion, measuring about 2.5 cm in its greatest diameter was noted in the rectum and biopsies were obtained. Histological examination (shown below) revealed multiple fragments of gastric mucosa with associated with mild chronic inflammation. How is this tumour best described?
Heterotopia - usually associated with inflammation as well but generally harmless
Which type of tumour invades connective tissue?
Malignant tumours often invade connective tissue, whereas benign tumours do not.
In the “TNM” system of tumour grading, what do the letters T, N and M represent?
Tumour
Nodes
Metastasis
How do name/ classify neoplasms?
primary description of a neoplasm is based on the cell origin, the secondary is whether it is benign or malignant
What does the suffix “sarcoma” mean?
Malignant (soft tissue) tumour
What does the suffix “oma” mean?
Benign tumour
What does the suffix “sarcoma” mean?
malignant (soft tissue) tumour
What is a benign and malignant tumour of squamous epithelium, and give examples.
Benign= Squamous papilloma
Malignant= squamous cell carcinoma
example(s)= skin, oesophagus, cervix
What is the name of a malignant and benign tumour of glandular epithelial cells, and give examples.
Benign= Adenoma
Malignant= Adenocarcinoma
example(s)= breast, colon, pancreas, thyroid
What is the name of a malignant and benign tumour of transitional epithelial cells, and give examples.
benign = transitional papilloma
malignant = transitional cell carcinoma
example(s)= bladder
what is the name given to a benign and malignant tumour of smooth muscle?
benign= Leiomyoma
malignant= leiomyosarcoma
What is the name given to benign and malignant tumours of the bone?
Osteoma = benign
Osteosarcoma = malignant
What is the name given to benign and malignant tumours of lymphocytes, and give examples.
benign= extremely uncommon
malignant= lymphoma
example(s)= gastric lymphoma
What is the name given to benign and malignant tumours of bone marrow, and give examples.
benign= extremely uncommon
malignant= leukaemia
example(s)= acute lymphoblastic leukaemia, chronic myeloid leukaemia
What are teratomas?
Tumours derived from germ cells and can contain tissue from all three germ layers
They may contain mature and/or (immature) tissues and even cancers
What are the three germ layers?
endoderm, ectoderm, mesoderm
What does invasion mean?
The direct extension into the adjacent connective tissue or other structures like blood vessels
What are the 4 exceptions for malignant tumours with the suffix “oma”?
lymphoma
melanoma
hepatoma (liver cell cancer)
teratoma (not all are malignant)
What are the four main differences between benign and malignant tumours?
- invasion
- metastasis
- growth patterns
- differentiation
What distinguishes dysplasia/ carcinoma in situ from cancer?
Invasion
What is meant by metastasis?
The spread of cancer via the blood vessels
NB: all malignant tumours have the capacity to metastasise although they may be diagnosed before they have done so
What is meant by the degree of differentiation?
How much does the architecture of the tumour resemble the cells of the tissue it is derived from
How do tumour cells differ from the cells they are derived from?
They have a larger nuclei (so higher nuclear:cytoplasm ratio) and more mitoses than the normal tissue they are derived from
May also show abnormal mitoses and marked nuclear pleomorphism
What is meant by growth pattern?
how much does the architecture of the tumour resembles the architecture of the tissue it is derived from.
How does the growth pattern of tumours differ from that of the tissue it is derived from?
less well defined architecture than the tissue they are derived from
Describe how a benign tumour becomes malignant?
- hyperproliferation
- adenomatous polyps form
- when the polyps undergoes dysplasia - becomes pre cancerous
- then forms an adenocarcinoma and then becomes an invasive cancer
By which routes do tumours spread?
Direct extension.
Haematogenous.
Lymphatic
Transcoelomic
Perineural
What are three stages involved in the direct extension of a tumour?
(Direct extension is associated with a stromal response to the tumour)
fibroblastic proliferation (“ a desmoplastic response”), vascular proliferation (angiogenesis) and an immune response.
which blood vessels are usually invaded in haematogenous invasion and why?
The blood vessels usually invaded are the venules and capillaries because they have thinner walls.
By what route do most sarcomas metastasize through?
Haematogenous (blood vessels)
Which cancers metastasize via the lymphatics first?
Epithelial cancers
How is the pattern of lymphatic spread dictated?
dictated by the normal lymphatic drainage of the organ in question
What does lymphatic metastisising involve?
via lymphatics to lymph nodes and beyond
What is meant by transcoelomic spread?
This is via seeding of body cavities.
Which cavities are common sites for transcoelomic spread?
pleural cavities for intrathoracic cancers and peritoneal cavities for intra-abdominal
What is perineural spread?
Spread of cancer via nerves
(underappreciated route of cancer spreads)
How do we assess tumour spread?
- Clinically
- Radiologically
- Pathologically
How do we describe tumour spread (stage)?
T = Tumour: the tumour size or extent of local invasion
N = Nodes: number of lymph nodes involved
M = Metastases: presence of distant metastases
This is called the “TNM” system and the details are different for each kind of cancer
What is meant by grade and stage?
Grade = how differentiated is the tumour
Stage = how far has the tumour spread - TNM
In terms of prognosis which is more important, grade or stage?
stage is more important than grade
What is the difference between benign and malignant tumours?
Benign…
Well differentiated
Slow growing
Does not metastasise
Does not invade surrounding tissue/ basement membrane
Malignant…
Poorly differentiated
rapidly growing
Can metastasise
Can invade surrounding tissue/ basement membrane
What is a malignant neoplasm of plasma cells called?
Myeloma
What is a malignant and benign neoplasm of neurones called?
neuroblastoma (malignant) and neuroma (benign)
What is a malignant and benign neoplasm of glial cells called?
glioblastoma (malignant) and glioma (benign)
