Week 8 - Neoplasia 1 Flashcards
What is a neoplasm?
An abnormal growth of cells that persists after the initial stimulus is removed
What are malignant neoplasms?
An abnormal growth of cells that persists after the initial stimulus is removed and invades surrounding tissue with potential to spread to distant sites
What is a tumour?
Any clinically detectable lump or swelling
What is cancer?
Any malignant neoplasm
What is a metastasis?
A malignant neoplasm that has spread from its original site to a new non-contiguous site
- The original location = the primary site
- The place to which it has spread = secondary site
What is dysplasia?
A pre-neoplastic alteration in which cells show disordered tissue organisation
- Represents altered differentiation
- Not neoplastic because the change is reversible
What are benign tumours?
Tumours that grow in a confined local area and so have a pushing outer margin
- Hence they are so rarely dangerous
What are malignant tumours?
Have an irregular outer margin and shape
- May show areas of necrosis and ulceration
What is anaplasia?
When cells have no resemblance to any tissue
What is pleomorphism?
Variation in size and shape of cells and nuclei
What is progression?
The process by which a neoplasm emerges from the monoclonal population
- It is characterised by the accumulation of mutations
Describe the cells in benign neoplasms
Cells closely resemble the parent tissue
Describe the cells in malignant neoplasms
- Range from well to poorly differentiated
- Cells may be anaplastic
- With worsening differentiation, individual cells have:
- – Increasing nuclear size
- – Increasing nuclear to cytoplasmic ratio
- – Increased nuclear staining
- – More mitotic figures
- – Pleomorphism
What is the difference between in-situ carcinomas and invasive carcinomas?
- In-situ: no invasion through epithelial basement membrane
- Invasive: penetrated through basement membrane
What causes the mutations seen in neoplasms?
Initiators and promoters
- Initiators are mutagenic agents
- Promoters cause cell proliferation
- Combined, they result in an expanded monoclonal population of mutant cells
- Main initiators = chemicals, infection, radiation
Mutations can sometimes be inherited
How do genetic alterations affect proto-oncogenes?
It causes them to become abnormally activated
How do genetic alterations affect tumour suppressor genes?
Causes them to become inactivated
- They normally suppress neoplasm formation
Describe the naming of neoplasms
- Benign: end in -oma
- Malignant: end in -carcinoma if epithelial, -sarcoma if stromal
What type of neoplasms are these?
- Leukaemia
- Lymphoma
- Myeloma
- Malignant neoplasm of blood-forming cells arising in the bone marrow
- Malignant neoplasms of lymphocytes, mainly affecting lymph nodes
- Malignant neoplasm of plasma cells
What are germ cell neoplasms?
Arise from pluripotent cells
- Mainly in the testis or ovary
- E.g. malignant teratoma, seminoma
What are neuroendocrine tumours?
Arise from cells distributed throughout the body
- E.g. carcinoid, pheochromocytoma
What type of neoplasms are these?
- Blastoma
- Adenoma
- Papilloma
- Adenocarcima
- Neoplasms that occur mainly in children and are formed from immature precursor cells
- Benign glandular epithelial neoplasm
- Tumour with finger-like projections, may be squamous so from skin/buccal mucosa
What type of neoplasms are these?
- Adenocarcinoma
- Squamous cell carcinoma
- Malignant glandular epithelial neoplasm
- Malignant stratified squamous epithelial neoplasm
Name some benign connective tissue neoplasms
- Fibroma = fibrous tissue
- Osteoma = bone
- Leiomyoma = smooth muscle
- Chondroma = cartilage
- Lipoma = fat
- Neuroma = nerve
- Neurofibroma = nerve sheath
- Glioma = glial cells
Name some malignant connective tissue neoplasms
- Fibrosarcoma = fibrous tissue
- Osteosarcoma = bone
- Leiomyosarcoma = smooth muscle
- Chondrosarcoma = cartilage
- Liposarcoma = fat
- Malignant glioma = glial cells
