Resection of Tumours Flashcards
What is tumour biology?
What a tumour is and how it behaves
What is tumour biology used to dictate?
○ When to operate or not to operate
○ What operation to perform
○ Other therapy
○ What should the surgical margins be?
What types of oncological surgery are there?
Prophylactic surgery
Diagnosis and staging
Definitive excision
○ Most commonly used
Palliative surgery
○ Alleviate clinical signs
○ Help for as much time as possible
Cytoreduction
○ Can’t remove it all
○ Could respond well to other therapy
○ Remove as much as possible
Management of oncological emergencies
○ E.g. Bleeding splenic tumour
Surgery for supportive therapy
○ E.g. Placing a feeding tube
Treatment of metastatic disease
○ Rarely occurs in veterinary medicine
What is prophylactic surgery?
Preventative surgery
Reduces risk of developing tumour
Example - ovariohysterectomy
○ Significant impact on whether bitch will develop mammary neoplasia later in life
What is an oncological emergency?
Any acute possible morbid or life-threatening events in patients with cancer
What should you do in an oncological emergency?
Deal with the immediate problem rather than trying to remove tumour
Presented as emergency cases
E.g. bleeding into abdomen due to splenic tumour
What is the difference between diagnosis, grading and staging
Diagnosis - tells you type of tumour
Grading - tells you malignant tendencies
Staging - tells you the extent to which a tumour has spread
What does a surgeon need to know about the tumour to determine surgical margins?
Type of tumour
Grade
How do you determine tumour type?
Cytology
FNA
Impression smears
How do you grade a tumour?
Histology
Core biopsy
Punch biopsy
Incisional biopsy
Excisional biopsy
How do you stage a tumour?
Radiography
Ultrasound
CT (usually best option)
Occassionally MRI
Tumour Terminology - T
Tumour
Tumour Terminology - P
Pseudocapsule
○ Compressed cancer cells and fascial layers
○ Appearance of discrete capsule
○ Not an actual barrier
Not connective tissue!
Tumour Terminology - R
Reactive
Often has inflammation
Tumour Terminology - Sk
Skip metastases
Outside of reactive zone
Tumour Terminology - St
Satellite metasteses
Within reactive zone
What is the surgical dose?
How much surgery to do
What types of definitive surgery are there?
Debulking/intralesional/cytoreduction
Cytoreductive surgery
Going to leave some cancer behind
Marginal excision
Wide excision
Radical excision
What is Debulking/intralesional/cytoreduction?
Cutting through a lesion
Leaves macroscopic volumes of tumour behind
Tumour will recur unless given adjuvant therapy (chemo/radiation)
What is marginal/local excision?
- Excision immediately outside of pseudocapsule (Within reactive zone)
- Leaves behind microscopic volumes of tumour
- Minimal amount of surrounding tissue removed
- Local recurrence likely without adjuvant therapy (chemo/radiation)
- Why?
○ Difficult to close wound
○ Difficult to get margins beyond Pseudocapsule
What is wide excision?
Removal of all tumour with complete margins of normal tissue in all directions
Local recurrence is unlikely
Outside of reactive zone
Lateral margins can be straight forward
Deep margins can be difficult
Depends on anatomy
What tissue makes an effective barrier against the spread of cancer?
Collagen-rich relatively avascular tissues
○ Fascia
○ Ligaments
○ Tendons
○ Cartilage
Sub-cut fat is not particularly effective as a margin
○ Relatively little resistance to invading tumour cells
