How Tumours Behave Flashcards
What is a neoplasm?
- An abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of normal tissue
- The proliferation is purposeless and continues without regard to its effect on the surrounding tissues or the requirements of the organism as a whole
What are the characteristics of benign vs malignant neoplasms?
Benign:
* Remain localised
* Do not spread to other organs
* Growth by expansion
Malignant:
* Infiltrate adjacent tissues
* Can spread (metastasise) to distant parts of the body via blood and lymphatics
Give examples of benign vs malignant tumours
Benign:
* Adenoma
* Haemangioma **
* Papilloma**
* Chondr**oma **
Malignant:
* Squamous cell carcinoma
* Adenocarcinoma **
* Angiosarcoma**
* Chondrosarcoma
Define the characteristics of:
* Differentiation
* Rate of growth
* Local invasion
* Metastasis
of benign vs malignant tumors
Differentiation
Benign: well differentiated, structure sometimes typical of tissue of origin
Malignant: lack of differentiation (anaplasia); structure often atypical
Rate of growth
Benign: Progressive and slow, may come to standstill or regress
Malignant: Erratic, may be slow to rapid, mitotic figures may be numerous and abnormal
Local invasion
Benign: masses that do not invade or infiltrate surrounding normal tissue
Malignant: Locally invasive, infiltrating surrounding tissue
Metastasis
Benign: absent
Malignant: more likely with large undifferentiated primary tumours
Define:
* Neoplasia
* Tumour
* Cancer
- Neoplasia = neoplasms in general (benign and malignant)
- Tumour = neoplasm
- Cancer = malignant neoplasm
Define metastasis
- Shifting of a disease from one part of the body to another
Usually used to describe deposits of cancer away from primary tumour site
What is tumour grade and what are the characteristics of grade 1-3?
- The extent to which the tumour resembles tissue of origin and the anatomical extent of the tumour
- Grade 1: well-differentiated
- Grade 2: moderately differentiated
- Grade 3: poorly differentiated
What does TNM staging stand for?
- T - tumour size
- N - number of regional lymph nodes containing tumour metastases
- M - distant metastasis present or absent
What’s a paraneoplastic syndrome?
- Clinical effects of malignant diseases not directly related to the local mass
- Commonest cause is secretion of functional hormones or peptides from the tumour
What is hypercalcaemia?
- Secretion of parathyroid hormone-related protein by tumour cells
What are the localised and systemic effects of carcinomas?
Localised
* Pressure
* Infiltration
* Invasion and destruction
Systemic
* Metastatic deposits (direct seeding, lymphatics, blood vessels)
* Paraneoplastic syndromes
Does cancer of the lung arise by undergoing metaplasia then dysplasia?
- No - lung cancer can arise from epithelial dysplasia without undergoing metaplasia
What is the pre-malignant phase of intraepithelial neoplasia?
- Normal epithelium
- Metaplasia
- Intraepithelial neoplasia (dysplasia)
- Carcinoma
or
1. Normal epithelium
2. Dysplasia
3. Carcinoma
