Neoplasia Flashcards
What is a neoplasm? What are the different classifications?
Abnormal tissue mass who’s growth exceeds and is uncoordinated from normal tissue and persist after the healing and repair process (i.e. after damaging stimulus is removed)
Benign
Malignant= cancer
What is the difference between a driver mutation and a passenger mutation? How are these mutations involved in cancer development?
Driver= mutation with survival benefit for cell which promotes cancerous change
Passenger= biological inconsequential mutation
Driver and passenger mutations accumulation to produce a genetically heterogenous cancers with different subclones
What are the cytological features of cancer and why do they occur?
Increased nuclear cytoplasmic ratio i.e. large nuclei with little cytoplasm
Nuclear pleomorphism i.e. variation in nuclear size and shape
Nuclear hyperchromasia i.e. dark staining nuclei due to increase density of chromatin
Prominent nucleoli i.e. due to clusters of chromatin
Increased mitotic activity
How would you differentiate microscopically between benign and malignant neoplasms?
Benign: Normal nuclear size Small nucleoli Absent pleomorphism Infrequent mitosis Good differentiation
Malignant: Enlarged nuclear size Prominent nucleo Marked pleomorphism Frequent mitosis Variable differentiation
How would you differentiate between benign and malignant tumours macroscopically?
Benign; Well circumscribed Generally small Haemorrhage usual Ulceration unusual Necrosis unusual Lack of invasion into surround tissue No metastasis
Malignant: Irregular Generally larger Haemorrhage Ulceration Necrosis Invasion to local tissues Metastasis
Which cancer is commonly associated with seeding to the peritoneum?
Ovarian cancer
What processes are required for tumour cells to undergo invasion and metastasis? What enzymes are involved?
Loosening of cell junctions
- E-cadherin mutation
- epithelial-mesenchymal transition (EMT)
Degradation of ECM
- MMP (matrix metalloproteinases) to enable migration through stroma
- Cathepsin D
- Urokinase plasminogen activator
Migration of tumour cells
-actin cytoskeleton contracts to enable movement through stroma
What is involved in epithelial-mesenchymal transition?
Expression of cytoproteins lost= loss of epithelial architecture
Actin expressed= enables increased cell motility i.e. mesenchymal characteristic
What are the 3 types of cancer invasion? What are the implications of these types of invasion?
Stromal
-degradation of tissue
Perineural
- cancer-associated pain due to nerve irritation
- can cause problems with surgical resection due to neoplasm associated with the nerve not being able to be removed
Venous
-dissemination + spread to distant sites
What organs to cancers commonly metastasis to?
Liver
Lungs
Bones
Brain
What are the 3 main routes of metastatic spread? What are the consequences of cancer spreading via these routes?
Lymphatic spread (tumour spread to LN ) -LN invasion
Haematogenous (occurs later)
-widespread dissemination
Seeding in body cavities (local) i.e. peritoneum
-tumour cells break from mass and implant onto surface
I.e. omental cake
lymphatic spread is earliest pathway before haematogenous spread
Why does cancer spread to veins preferentially to arteries?
Veins have thinner walls
What is the difference in growth characteristics between benign and malignant?
Benign:
Slow growing
Spontaneous arrest common
Malignancy
Rapid growth
Spontaneous arrest rare
How would you differentiate between a malignant melanoma and a benign naevus (mole)?
Malignant melanoma: Large (20mm) Variable pigmentation Irregular border Partly flat and partly raised Asymmetrical
Benign naevus: Small (3mm) Uniform Well-defined border Polypoid Symmetrical
Which cancers are associated with bone mets? What are the different types of bone lesions and their implications?
Lung Breast Thyroid (follicular carcinoma) Prostate Kidney I.e. organs which are bi-lobular or have 2 components
Lytic lesions= destruction
Sclerotic= bone formation
Pain + fractures (can present before primary tumour site identified)
