OP09 OSCC II Flashcards
(17 cards)
What is the technique for a biopsy?
o 1. After 2 weeks of removing possible causes.
o 2. Explain the purpose & nature of the operation to patient
o 3. Take the biopsy from a representative part of the lesion (eg worst/most suspicious parts) - Also include normal tissue
o 4. Plan the incisions before starting, if needed, outline them with a surgical marker
o 5. Infiltrate for local anaesthesia to reduce bleeding, but not in the lesion
o 6. Make each incision with a single bold stroke
o 7. Hold the biopsy at one end and gently dissect its deep margin
o 8. Place the biopsy on a piece of gauze until the operation has been completed
o 9. Close the wound with interrupted sutures
o 10.Place the biopsy in fixative
o 11.Label the bottle containing the biopsy and fixative
o 12.Complete a form requesting histological examination of the biopsy and send both to the histology laboratory
What does chemical fixative prevent?
Autolysis
Putrefaction
Bacterial and fungal colonisation
What does fixative do?
Preserves tissues as close as possible for histological analysis
Examples of fixatives
Formalin
(saline and chlorhexidine are not fixatives)
What the the contraindications for taking a biopsy?
- No confidence in own ability
- Pt has uncontrolled systemic disease
- Pt has infection as site of biopsy
- Suspect it might be a vascular lesion
- Pt is in considerable pain from lesion
- Lesion is not accessible
- Lesion is large and there is little doubt that it is cancer
- Fast track referral without biopsy
What sorts of invasion can cancers do?
Infiltration - local
Metastasis - distant
(if it invades it is a cancer!!)
What is seen in local invasion?
Infiltrative growth
Local aggressive behaviour
No capsule
Where can local invasion be to?
Lamina propria
Bone
Muscle
Neural invasion
Where can cancers metastasise to?
- Lymphatic system
- Blood streams
- CSF
- Implantation (serose liquid)
- Paradoxical (against the flow of the blood)
What cellular and tissue aplasia occurs in cancers?
Hyperchromatism
Increased N/C ratio
Nuclear pleomorphism
Supra-basal mitoses
Bizarre mitoses
Loss of polarity (loss of architecture of epithelial layers)
Abnormal synthesis
What prognostic features of cancers are there?
Degree of differentiation
Chronic inflammatory cells in the stroma
Tumour cells in blood vessels or lymphatics
Tumour cells at excision margins
Tumour in regional lymph nodes
TNM system
What does TNM stand for?
T - extent of primary tumour and depth of invasion
N - presence and extent of regional lymph node metastasis, extracapsular spread
M - absence or presence of distant metastasis
What do the numbers in TNM mean?
Indicate extent of malignant disease
What does G mean?
The histopathological grading - how differentiated it is
What does the R mean?
Residual tumours after radiotherapy
What is staging?
Depends on some grouping between TNM categories
TNM for oropharyngeal tumours also varies according to HPV status
What is tumour differentiation?
How well the tumour resembles the original cells - well differentiated, moderately, poorly, undifferentiated = anaplastic
