Neoplasia Flashcards
(33 cards)
What is neoplasia?
An excessive, irreversible and uncontrolled growth which persists even after withdrawal of the stimuli which caused it
Hyperplasia
Increase in number of cells
Hypertrophy
Increase in cell size
Atrophy
Decrease in cell size
Metaplasia
Cell changes from one type to another e.g. squamous epithelium in oesophagus to become glandular
Apoptosis
Programmed cell death - body recognises cell is not viable
Necrosis
Uncontrolled cell death e.g. large cancer and cells in the middle cannot get blood supply so die
Inflammation
A reaction to cell death - a clean up
Dysplasia
Abnormal or atypical cells due to a failure of differentiation
- (sometimes called intraepithelial neoplasia)
- degree of dysplasia helps the pathologist identify those tissues which are high risk for malignancy in the future
Metastasis
Where invasive neoplasm spreads to other areas of the body through:
- lymphatics
- blood
-
Cellular changes to help respond to stress
- normal?
- hyperplasia (increase in cell number)
- hypertrophy (increase in cell size)
- atrophy (decrease in cell size)
- metaplasia (change in cell shape/structure)
Further responses to stress
- apoptosis (programmed cell death)
- necrosis (uncontrolled cell death)
- inflammation (clean up reaction to cell death)
- (possibly) neoplasia
Characteristics of benign disease?
- localised
- well encapsulated
- slow growing
- resembles the tissue of origin
- regular nuclei
- few mitoses
- damage at local level
How does the pathologist decide about the degree of dysplasia?
- Disordered architecture of the tissue: loss of normal structure
- Disordered cellular features: known as cellular atypia:
- pleomorphic nuclei
- mitotic figures
Pleomorphic
Variation in the size and shape of cells or their nuclei
Mitotic figure
A cell that is in the process of dividing to create two new cells
Characteristics of malignant disease?
- invasive
- can metastasise
- grows fast
- may not resemble the tissue of origin
- shows features of dysplasia
- damage at local or distant sites
Transcoelomic
Spread of malignancy into body cavities that occurs via penetrating the surface of the peritoneal, pleural, pericardial or subarachnoid spaces
Cancer of unknown primary
When we have metastasis but cannot easily identify the site the cancer originated in:
- requires a pathologist to try and identify, if possible, the origin of the. cancer to help direct treatment
Epithelial neoplasms
- Originates from covering epithelia = papilloma if benign, carcinoma if malignant.
- Originates from glandular epithelia = adenoma if benign, adenocarcinoma if malignant.
- Originates from solid organ epithelia = adenoma if benign, organ carcinoma if malignant
Connective tissue neoplasms
- Smooth muscle - leiomyoma - leiomyosarcoma
- Skeletal muscle - rhabdomyoma - rhabdomyosarcoma
- Bone forming - osteoma - osteomasarcoma
- Cartilage - chondroma - chondrosarcoma
- Fibrous - fibroma - fibrosarcoma
- Blood vessels - angioma - angiosarcoma
- Adipose - lipoma - liposarcoma (liposuction)
Miscellaneous neoplasms
- Lymphoid - lymphoma (malignant only)
- Haematopoietic - leukaemia (malignant only)
- Primitive nerve cells - very rarely benign - neuroblastoma, retinoblastoma etc
- Glial cells - gliomas (e.g. astrocytoma) (malignant only)
- Melanocytes -pigmented naevi (moles) - malignant melanoma
- Mesothelioma - malignant mesothelioma
- Germ cells - Teratoma - teratoma, seminoma
Explain the importance of cell signalling in terms of directing treatment
HER2 in breast cancer:
- HER2 works via a receptor tyrosine kinase pathway
- overexpression of HER2 in breast cancer suggests a more aggressive cancer
- good treatment options can be chosen which target HER2 positive breast cancers (ie trastuzumab/Herceptin)
Microsatellite instability (MSI)
MSI occurs when there is a failure of the mechanism to repair damaged DNA in the cell cycle:
- this repair system is known as the mismatch repair system
- there is damage to the mismatch repair system then damaged DNA can be passed down to new cells and make them to prone to mutations which cause cancer
- the higher chance of mutation caused by a failure of the mismatch repair system is known as MSI
- MSI can guide prognosis and treatment as seen in colon cancers
