Oncology 2 Flashcards
- What are 2 critical pieces of info to determine to aid decisions regarding treatment and prognosis.
- What are the aims of investigations?
- Type of tumour.
- Spread of tumour.
- Type of tumour.
- Make a histological/cytological diagnosis.
- Determine the extent of local and distant spread.
- Investigate and treat any tumour-related or concurrent complications.
- To determine the patient’s ability to tolerate therapy.
- To determine the overall prognosis.
- Make a histological/cytological diagnosis.
Diagnostic approach to cancer.
- History.
- PE.
- Lab testing.
- Imaging.
- Biomarkers (generally unreliable).
- Biopsy.
– Cytology.
– Histopathology.
Some questions to ask on history taking.
When was the mass first noticed?
Is the patient aware?
Change in appearance?
Any other masses?
Any signs of systemic illness?
– lethargy and exercise intolerance w/ anaemia.
– PUPD w/ hypercalcaemia.
CE.
- Full CE for evidence of metastasis and/or paraneoplastic effects.
- Location.
- Dimensions.
- Character e.g. fluctuant or firm.
- Response to palpation.
- Mobility.
- Margination.
- Available margins.
What does an accurate diagnosis require?
A microscopic examination of representative tissue or cells.
A diagnosis cannot be made upon palpation or diagnostic imaging alone.
- How can cytology samples be collected?
- What info can we gain from cytology samples?
- Touch / impression preparations.
- FNA.
- Cytospins of body fluids / effusions.
- Touch / impression preparations.
- Nature of the tumour (e.g. spindle, vs round, vs epithelial) to help identify cytological features of malignancy.
Advantages of FNA and cytology.
- Quick, cheap, easy, non-invasive.
- In house, may feel comfortable to distinguish inflammatory vs neoplastic lesions.
- In house, can readily differentiate mast cell tumours from lipomas.
- Easy to send these samples away for an expert opinion from a clinical pathologist.
Disadvantages of FNA and cytology.
- Results more likely to be inconclusive than with histopathology.
- There are some risks to consider in approach.
– Can you remove seeded cells along needle tracts in subsequent surgery?
– Degranulation of MCTs (rare).
– Bleeding w/ some types of malignancy is more likely. - Doesn’t allow assessment of tissue architecture and grading of tumours not possible.
- What do histology samples involve?
- Common biopsy collection method.
- Whole pieces of tissue of histopathological examination.
- Punch biopsy.
What does a histology sample allow that a cytology sample does not?
Tumour grading.
Define tumour grading.
The microscopic assessment and quantification of parameters that correlate w/ the clinical aggressiveness of a neoplasm based on the tumour’s architecture.
– invasion of adjacent tissues?
– evidence of metastatic behaviour e.g. presence of neoplastic cells in local blood vessels and/or lymphatics?
Biopsy techniques.
Incisional or excisional.
- Incisional biopsy.
- Excisional biopsy.
- Small incision into area of abnormal tissue and small piece removed.
- Entire lump or suspicious area surgically excised.
- Advantage of incisional biopsy.
- Disadvantage of excisional biopsy.
- Can grade tumour, make definitive diagnosis, assess local aggressiveness prior to surgical planning.
- Taking a gamble as don’t have info yet.
So do not know how much healthy tissue need to leave around tumour in order to remove it in its entirety.
Rules of performing incisional biopsy.
1) Avoid superficial ulceration, inflammation and necrosis.
2) Ensure adequate depth.
3) Try to include a boundary between tumour and normal tissue.
4) Do not predispose to local tumour recurrence or dissemination e.g. via instruments/bleeding.
5) Do not compromise subsequent therapy.