Week 8: Neoplasia 1 Flashcards
What is the traditional definition of neoplasia?
An abnormal mass of tissue, the growth of which exceeds and is uncoordinated with that of normal tissues and persists in the same excessive manner after the apparent cessation of the stimuli that evoked the change
What is the modern definition of neoplasia?
A disorder of cell growth that is triggered by a series of acquired mutations affecting a single cell and its clonal progeny. These mutations give the cells a survival and growth advantage resulting in excessive proliferation that is independent of physiologic growth signals
What are the 2 components of a neoplasm?
Parenchyma and Stroma
What is the parenchyma of tumour?
- Neoplastic cells that make up the tumour
- Classification is based on these cells
- Biological behaviour of tumour is largely determined by these cells
What is the stroma of a tumour?
- Connective tissue, vessels and inflammatory cells
- Influence growth and spread
- Lots of collagen
How do we name mesenchymal benign tumours?
cell type of origin + oma
i.e. Chondroma, Fibroma, Lipoma
What is an Adenoma?
A benign epithelial neoplasm that is derived from glandular tissue
What is a Papilloma?
A benign epithelial neoplasm comprised of finger-like projections
What is a Cystadenoma?
A lesion that forms cystic masses
What is a Polyp?
A macroscopically visible projection above a mucosal surface
How do we name a malignant tumour arising from epithelial cells?
Region of origin + carcinoma
i.e. Adenocarcinoma, Squamous cell carcinoma
How do we name a malignant tumour arising from mesenchymal cells?
Region of origin + sarcoma
i.e. Chondrosarcoma, Osteosarcoma
How do we name malignant tumours arising from the blood forming cells?
Leukaemia or Lymphoma
What is a mixed tumour?
A tumour whose parenchymal cells show different differentiation, they are pleomorphic
What is a teratoma?
A tumour containing mature cells from more than one germ layer, they contain a multitude of tissues
What are the macroscopic features of benign tumours?
- Well circumscribed
- Even cut surface
- No necrosis or haemorrhage
- May have a capsule
- May compress surrounding tissue
What are the microscopic features of a benign tumour?
- Well organised
- Similar appearance to normal tissue
- No cytological features of malignancy
What are the macroscopic features of malignant tumours?
- Irregular, infiltrative outline
- Necrosis and haemorrhage
- May invade adjacent structures
What are the microscopic features of a malignant tumour?
- Diosrganised architecture
- Nuclear pleomorphism (variation in size and shape)
- Increased Nucleus:Cytoplasm ratio
- Hyperchromasia
- Mitotic cells
- Disorder, loss of polarity
Define dysplasia:
Disordered growth of tissue
What are the characteristics of dysplasia:
- Typically in epithelia
- Loss of uniformity
- Disorganisation
- Loss of differentiation
- Nuclear enlargement
- Hyperchromasia
- Pleomorphism
What is carcinoma in situ?
A neoplasm whose dysplastic changes are marked and involve the full thickness of the epithelium (without penetrating the basement membrane).
What is metastasis?
The spread of a tumour to sites that are physically discontinuous with the primary tumour
They mark tumours as malignant