Session 8 ILO's Neoplasia 1 Flashcards
Neoplasm
Neoplasm = abnormal growth of cells that persists after the initial stimulus is removed (irreversible)
Dysplasia
Dysplasia = pre-neoplastic alteration in which cells show a disordered tissue organisation (technically reversible)
Tumour
Tumour = a swelling i.e. any clinically detectable lump or swelling
Cancer
Cancer = colloquial term for a malignant neoplasm which is: abnormal growth of cells that persists after the initial stimulus is removed AND invades surrounding tissue with the potential to spread to distant sites
Metastasis
Metastasis = a malignant neoplasm that has spread from its original site to a new, non-contiguous site
Anaplasia
Anaplasia = cells with no resemblance to any tissue; cells appear primitive and lack specialization along any particular cell line
Pleomorphism
Pleomorphism = variety in cell size or shape (i.e. a large hyper chromatic nucleus with a high nucleus to cytoplasm ratio)
Progression
Progression = process by which a neoplasm arises from monoclonal cells, followed by the accumulation of yet more mutations
Differentiation
Differentiation = the process of becoming different by growth or development
In situ
In situ = no invasion through epithelial basement membrane
Understand, explain and define the terms: neoplasm, dysplasia, tumour, cancer, metastasis, anaplasia, pleomorphism, progression, differentiation and in situ.
Neoplasm = abnormal growth of cells that persists after the initial stimulus is removed (irreversible)
Dysplasia = pre-neoplastic alteration in which cells show a disordered tissue organisation (technically reversible)
Tumour = a swelling i.e. any clinically detectable lump or swelling
Cancer = colloquial term for a malignant neoplasm which is: abnormal growth of cells that persists after the initial stimulus is removed AND invades surrounding tissue with the potential to spread to distant sites
Metastasis = a malignant neoplasm that has spread from its original site to a new, non-contiguous site
Anaplasia = cells with no resemblance to any tissue; cells appear primitive and lack specialization along any particular cell line
Pleomorphism = variety in cell size or shape (i.e. a large hyper chromatic nucleus with a high nucleus to cytoplasm ratio)
Progression = process by which a neoplasm arises from monoclonal cells, followed by the accumulation of yet more mutations
Differentiation = the process of becoming different by growth or development
In situ = no invasion through epithelial basement membrane
Describe and understand the difference between in-situ and invasive malignancy.
In-situ = showing all the features of malignancy but no invasion through epithelial basement membrane
Invasive = penetrated through epithelial basement membrane and spreading to non-contiguous sites
Explain how proto-oncogenes and tumour suppressor genes are involved in the development of neoplasms
Neoplasms can occur when either proto-oncogenes or tumour suppressor genes are altered:
Proto-oncogenes become abnormally activated (when they are then called oncogenes), favouring neoplasm formation.
Tumour suppressor genes, which normally suppress neoplasm formation, become inactivated.
Describe and understand the difference between benign and malignant tumours including macroscopic and microscopic features and biological behaviour.
Macroscopic/Microscopic differences:
Benign: (5)
- Cells are uniform throughout tumour
- Normal or mild increase in nuclear to cytoplasmic ratio
- Few mitoses
- Well differentiated (closely resemble parent cell/tissue)
- They have a pushing outer margin
Malignant: (5)
- Cells/nuclei vary in size and shape (pleomorphism)
- High nuclear to cytoplasmic ratio
- Many mitoses including abnormal forms
- Range from well to poorly differentiated(depends on proximity to origin) but in general, failure to differentiate fully
- Irregular outer margin and shape
Biological behaviour :
Benign Tumours: (4) •Grow in a confined local area •Do not produce metastases •Rarely dangerous (location) •Retained functions of their cells of origin
Malignant tumours: (5) •Expansive and invasive •Potential to metastasise •May have ulcerations and necrosis •Infiltrative •Less likely to retain functions of cells of origin and may sometimes acquire unexpected functions due to derangements in differentiation
Understand the reasoning behind the nomenclature given to benign and malignant neoplasms and the exceptions to this rule
Benign - end in ‘oma’ regardless of cell type
Malignant - ends in ‘carcinoma’ (if epithelial) or ‘sarcoma’ (if stromal)
Testicular neoplasms are the exceptions
A malignant tumours of the testis = all end in ‘Oma’
e.g. teratoma and seminoma = malignant
In the ovary, a teratoma is benign (ie dermoid cyst) so rule is not exception in ovaries
Hall Marks of Malignancy
With worsening differentiation the individual cells have:
- Increasing nuclear size
- Increased nuclear to cytoplasmic size
- Increased nuclear staining (hyperchromasia)
- Increased numbers of mitotic figures
- Abnormal mitotic figures (Mercedes Benz)
- Variation in size and shape of cells and nuclei (pleomorphism)
