Principles of tumours Flashcards
what is neoplasia?
A state of cell division without any external stimuli.
what is hypertrophy?
An increase in cell size
what is a neoplasm?
An abnormal mass of tissue with uncoordinated cell growth with no purpose
what are the characteristics of a benign tumour?
Slow growing Well circumscribed Encapsulated by a layer of compressed fibrous tissue not locally invasive no metastatic potential
what are microscopic characteristics of a benign tumour?
well differentiated as they closely resemble the cell of origin
The cells are uniform throughout the tumour
Few mitoses
normaly nuclei: cytoplasmic ratio
what are characteristics of a malignant tumour?
Fast growing
poorly circumscribed
metastatic potential
non-encapsulated
what are the microscopic characteristics of a malignant tumour?
Variable differentiation pleomorphism many mitoses nuclear staining high nuclear: cytoplasmic ratio
what are the main two characteristics of cancer?
Invasive growth
metastatic potential
what is a malignant epithelial tumour called?
Carcinoma
what is a malignant squamous epithelium tumour?
Squamous cell carcinoma
what is a malignant tumour of glandular epithelium?
adenocarcinoma
what is a benign tumour of glandular epithelium?
Adenoma
what is the most common type of malignant tumour in the adult population?
carcinoma; arising from the epithelium
how do carcinomas tend to metastasise?
via the lymphatic tissue
what is the most common type of carcinoma?
adenocarcinoma
squamous cell carcinoma
what are properties of an adenocarcinoma?
Gland formation
mucin production
signet ring cells
what are properties of a squamous cell carcinoma?
Keratin formation
intracellular bridges between cells.
what is grade an assessment of?
Differentiation
what does grade reflect?
how closely it resembles the normal tissue from which its arised.
who can grade tumours?
only a pathologist because you have to look down the microscope to measure differentiation
What does tumour grade correlate with?
How aggressive the behaviour is
what grading is used for most carcinomas?
A 3 tier system depending on the degree of differentiation
what grading system is used for renal cell carcinoma?
the Fuhrman system which is 4 tier
what grading system is used for prostatic carcinoma?
The gleason system which is 5 tiers.
What type of carcinomas aren’t graded at all?
small cell lung carcinomas
basal skin carcinomas
what is staging?
The process of determining how much cancer there is in the body and where it’s located. A measure of spread
in carcinoma what is the single most prognostic factor?
Stage
why do we stage patients?
- plan treatment
- prognostics
- help doctors communicate
- identify clinical trials
how do we stage a patient?
- clinical; physical exam
- radiologically; CT/MRI/PET
- surgical
- pathological
what is the most common system for staging?
TNM
what is required for a definite diagnosis of cancer?
A tissue for histology.
what are local symptoms of cancer?
Symptoms related to tissue destruction at the site of the cancer for example lung carcinoma causing cough
what are metastatic symptoms of cancer?
Related to secondary deposits of the cancer at distant organs
what are systemic symptoms of cancer?
Due to release of cytokines from tumour cells. prolonged fever, weight less etc
what is paraneoplastic syndrome?
syndromes caused by substances that are produced by tumour cells.
what are four ways cells can adapt to their environment?
Atrophy
hyperplasia
hypertrophy
metaplasia
what is metaplasia?
one mature cell type replaces another mature cell type meaning a change in the pattern of differentiation
What metaplasia can be caused in the cervix due to vaginal acid?
Columnar glandular epithelium becoming squamous epithelium
what is dysplasia?
Disordered growth or differentiation. it’s pre-malignant
what is carcinoma in situ?
Despite carcinoma this doesn’t mean epithelial cancer. it’s severe dysplasia.
T/F; have cells that have dysplasia/ carcinoma in situ invaded through the cell membrane?
NO
what are characteristics of cells showing dysplasia?
Larger nuclei, pleomorphism.
why are dysplasia and carcinoma in situ not considered cancer?
There are two main characteristics of cancer: invasive and ability to metastase. dysplasia and carcinoma in situ haven’t cross the basement membrane so aren’t invasive.
why is carcinoma considered cancerous?
it has crossed the basement membrane so shows invasive growth and metastatic potential
what is barretts oesophagus?
There is squamous mucosa in the oesophagus, GORD causing metaplasia into glandular mucosa.
