CA3: Pathology of neoplasia Flashcards
1. Define: tumour, neoplasm, benign, malignant, histogenesis, differentiation, metastasis 2. Give classification of benign and malignant neoplasms according to their cells of origin 3. Compare and contrast the pathological features of benign and malignant neoplasms 4. Describe the effects of neoplasms on the host
Define tumour
Swelling
Define neoplasm
Abnormally excessive out of control tissue growth continuing in absence of the initiating stimulus
To determine if a swelling is neoplastic, a biopsy must be taken as the tumour could be a result of an access/infection
What is neurofibromatosis
Benign tumour of nerve sheath origin
Why can some benign neoplasms be life threatening and give examples of this
Due to their site e.g.
- Meningioma causes increased intracranial pressure
- compressive effect on brain
- impacts vascular + CSF inflow and outflow - Insulinoma in islets of Langerhans produces insulin so can cause hypoglycaemia
What is basal cell carcinoma
Malignant tumour of the skin due to sun exposure; there is no metastasis and it is of localised origin so can be easily removed
- even though this is malignant it doesn’t cause much harm and only causes significant damage when left alone
What can neglected basal cell carcinoma result in
Erosion into the bone and localised spreading
Describe how normal squamous epithelium (skin) appears under a microscope and how this is different in squamous cell neoplasms
Normally; cells originate from basal zone and proliferate here, they will then mature and migrate to the surface and this is where the nucleus is lost from the cell and the cytoplasm will accumulate keratin
Neoplasm; protein on the surface has keratin and there are intercellular prickles (bridges), the cells are disorganised and the nucleus is enlarged
What is differentiation in terms of neoplasms
The degree to which a neoplasm resembles the normal cell of origin
- Well differentiated = close resemblance
- Poorly differentiated = little resemblance
This grading gives a prognostic indication of how the neoplasm will behave
Describe the visible differences in well and poorly differentiated adenocarcinoma
Well = tubular structures seen as it is a glandular epithelium
Poor = infiltration of other cells into the fibromuscular tissue, holes can be seen
What is anaplasia
Complete lack of differentiation in a neoplasm
What is small cell anapaestic carcinoma
Type of lung cancer derived from neuroendocrine cells where there is no differentiation microscopically and there is no cohesive structure, cells are present in sheets
A diagnosis cannot be made on biopsy alone
What is squamous cell papilloma
Benign neoplasm in stratified squamous epithelium e.g. skin
What is transitional cell papilloma
Benign neoplasm in transitional cell epithelium e.g. urogenital tract
What is an adenoma
Benign neoplasm of glandular epithelium e.g. in GIT
What is a lipoma
Benign connective tissue neoplasm in fat cells; this will be well circumscribed, have a uniform cut surface and be yellow in appearance due to being fat filled
What is leiomyoma
Benign connective tissue neoplasm in smooth muscle
What is neurofibroma
Benign connective tissue neoplasm in nerve
What is rhabdomyoma
Benign connective tissue neoplasm in striated muscle
