Neoplasia Flashcards
what is the definition of a tumour?
an excessive, uncontrolled proliferation of cells resulting from an irreversible genetic change
what is the definition of neoplasia?
- new growth
* another term for tumour growth
what is the definition of hyperplasia?
abnormal increase in cell number
what is the definition of hypertrophy?
abnormal increase in cell size, but the number of cells stays the same
what are the features of benign tumours? (5)
- stay localised at their site of origin
- slower growth rate (than malignant)
- fewer mitotic factors
- cells and nuclei are small, regular and uniform
- definition between tumour and normal tissue
what are the clinical effects of benign tumours? (3)
- local pressure
- bleeding
- torsion
what are the features of malignant tumours? (5)
- able to invade and spread to different sites (metastasise)
- faster growth rate (than benign)
- many mitotic factors (fast and uncontrolled proliferation)
- larger, pleomorphic cells with increased DNA content
- less definition between tumour and normal tissue
what are the basic clinical effects of malignant tumours? (4)
- local pressure
- tissue destruction
- distant metastasis
- paraneoplastic syndromes (eg. inappropriate hormone secretion)
what is a teratoma (2)
- tumour containing different cell types - a mixture of mature and immature cells
- originate from pluripotent germ cells (ovaries and testes)
what is the definition of dysplasia?
abnormal growth
what are the signs of disordered epithelial growth (intraepithelial neoplasia)?
cellular atypia (seen on biopsy) - increased mitotic factors and pleomorphic cells
what are the 2 ways in which solid cancers can spread?
- direct invasion of neighbouring tissue
* distant metastasis via blood / lymphatics
what change in tissue is usually associated with tumour infiltration? how is this change demonstrated in epithelial cells?
- loss of cell-cell cohesion
* invasion of the ECM
what are the 3 modes of cancer dissemination? give examples
- seeding within body cavities: growth across surface tissue without much penetration inwards - common in ovarian cancers
- lymphatic spread - favoured by carcinomas
- hematogenous spread (via BV) - favoured by sarcomas
what is the nomenclature of epithelial and connective tumours? give examples
epithelial
• begin: -oma (adenoma)
• malignant: -carcinoma (squamous cell carcinoma)
connective
• benign: -oma (osteoma)
• malignant: -sarcoma (osteosarcoma)
what are the 6 hallmarks of cancer? what are the consequences of each?
- self-sufficiency in growth signals - autonomous drive to proliferate
- insensitivity to growth-inhibitory signals - inactivation of tumour suppressors
- evasion of apoptosis - suppress / inactivate genes that enable apoptosis
- limitless replication potential - activate gene pathways that allow cells to become immortal
- sustained angiogenesis - draw out own blood supply
- tissue invasion + metastasis - capacity to migrate to, invade and colonise other tissues
