Neoplasia Flashcards
definitions: Tumour Neoplasia Malignant Benign Cancer Dysplasia
- Tumour - Swelling, now commonly a synonym for ’neoplasm’ - Neoplasia - AUTONOMOUS ‘new growth’ of abnormal cells - Malignant - ‘evil in nature’ / ‘tending to produce death’ - Benign - ‘gentle/kind’ so not harmful or not malignant - Cancer - Synonymous with ‘malignant neoplasm’ - Dysplasia - Autonomous new growth (malignant) that has not yet invaded anything
What are the three ways you classify a neoplasm? future of classification?
Behaviour - Benign, borderline, malignant Histogenesis - What’s the cell of origin? Differentiation - Which cells/tissues are seen in the tumour and how well do they resemble normal tissues? molecular classification is likely to become more important than the histogenesis as cells can morph and change
Characteristics of benign neoplasms
Remain localised Pushing, well circumscribed borders or encapsulated, no invasion Usually grow slowly Look similar to the parent tissue they have arisen from NO METASTASIS
Problems caused by benign neoplasms
- Pressure effects - Obstruction of hollow organs - Hormone production - Anxiety of the patient - Wide variety of clinical problems - Benign neoplasms may but generally do not transform into malignant neoplasms
define dysplasia
Dysplasia describes abnormal cell morphology worrying for a borderline or malignant neoplastic process. Most often seen in epithelial tissues. The cells don’t look normal any more. If dysplasia is seen in an epithelium and the basement membrane remains intact, the neoplasm cannot metastasize and cure is usually possible. This is often called ‘intraepithelial neoplasia’ e.g. CIN, PIN, … or ‘carcinoma in situ’ e.g. DCIS. Dysplasia may (or may not) progress to an invasive neoplasm.
Borderline Neoplasms characteristics
Limited invasion but local destructive growth May progress to frank malignancy Often curable Very unlikely to metastasize Examples: Serous borderline tumour of the ovary Basal cell carcinoma
Malignant neoplasms characteristics
- Invasion of surrounding tissues (not localised) - Infiltrative, poorly defined borders - Usually grow relatively rapidly - Variable resemblance to parent tissue METASTASIS
The Hallmarks of Cancer
- Resisting cell death / avoiding apoptosis
- Deregulating cellular energetics
- Self sufficiency in proliferative signaling
- Evading host immune responses
- Evading growth suppressors
- Activating invasion and metastasis
- Two enabling features:
- Genome instability and mutation,
- Tumour-promoting inflammation
- Enabling replicative immortality Induction of angiogenesis
General aetiologies
- Oncogenes
- DNA / gene mutations
- Translocations
- Viruses
- UV radiation
- Toxins
What is an oncogene?
Oncogene - a gene that has the potential to promote neoplasia
What problems do malignant neoplasms cause?
- Destruction of adjacent tissues
- Bleeding from ulcers
- Obstruction of hollow viscera
- Production of hormones
- Weight loss
- Anxiety of the patient
- Wide variety of clinical problems
- METASTASIS
What is the difference between grading and staging?
Grading describes how well the malignant neoplasm resembles normal tissue
Staging describes the anatomical extend of a malignant neoplasm
Explain Grading
Neoplasms vary in the extend to which they resemble normal tissues:
- The tissue from which they have arisen
- The tissue towards which they differentiate
The grade of a cancer correlates with prognosis
Examined by microscopic assessment / morphology.
Different classifications of grading:
Well differentiated
Moderately differentiated
Severely differentiated
High grade
Low grade
How is staging used in neoplasm
Staging reflects the anatomical extend of a cancer
Locally T = tumour
Lymph nodes N = nodes
Metastasis M = metastasis
Different stages will have different prognosis and are amenable to different sorts of treatment
Many different staging systems (individualized to the organ in question)
