Intro to Vet Oncology Flashcards
What questions should be asked when looking at a mass?
- How long has it been present, is it growing, how fast
- trauma?
- is it hot, erythematous or painful? indicates inflammatory lesion, though still could be a tumour
- solid or fluid filled? fluid could be abscess, cyst, seroma, haematoma or necrotic centred tumour
- well defined or ill defined? fixed to underlying tissues?
What 2 samples can be taken to further inestigate a mass? uses/pros and cons of each?
> FNA for cytology
-distinguish inflammaotry [neutrphils and mixed cell population] and neoplastic [one cell type predominates] lesions
-cell morphology can determine benign or malignant masses
-also good for bone marrow and effusions
-cytology NOT useful for tissue architecture, mitotic index, invasion or grading
Biopsy for histopathology (incisional, excisional, puch biopsy, tru-cut, Jamshid core biopsy)
- gold standard
- but expensive and requires sedation or GA
- decide whether malignant and give tumour a grade
What are the 3 possible cells of origin of a tumour?
- epithelial
- mesenchymal (=spindle cell = structural cells bone, cartilage, endothelium)
- round cell
WHat is tumour grade?
- assigned by PATHOLOGIST
- assessment of mitotic index, cellular differentation, invasion of tissues, necrosis etc.
- categorised as LOW, MEDIUM or HIGH
- low grade likely to be benign
- high grade likely to be malignant
What are the 2 numerical grading systems for describing mast cell tumours?
> Patnaik 1-3
> KIupel low or high (make people decide)
What is tumour staging?
- Performed by the CLINICIAN
- extent of the disease in the patient
- looking at primary tumour, lymph nodes and distant distant metastatic disease
What system is usually used for staging and what does each descriptor mean?
TNM
> Primary tumour
- size, mobility, relationship to surrounding tissues, ulceration and erythema
- may require imaging and endoscopy
> Draining lymph nodes
- size, mobility, relationship to surrounding tissues, texture, consistency
- imaging might be required
- FNA to assess as small nodes can be malignant and larger ones just hyperplastic
> Distant metastasis
- history and PE can give clues eg. coughing
- imaging: radiography or CT, ultraound, , MRI, scintigraphy
- lungs most common site of metastasis
- FNA/biopsy to confirm dx
- liver, spleen, kidneys, heart, skin, bones, CNS may also be site sof metastasis
How may the TNM system be refined?
Numerical grading
T1: 5cm
N0: no metastasis to regional LNs N1: LNs metastasis
M0: no distant metastasis M1: distant metastasis present
How does lymphoma grading systemdiffer to normal?
WHO staging system for canine lymphoma
1: single LN or lymphoid tissue in single organ exlcuding BM
2: more than 1 LN in a regional area +- tonsils
3: generalised LN involvement both side of diaphragm
4: liver +- spleen +- stage 3
5: blood bonemarrow or other organ systems +- stages 1-4
> sunstage a= without systemic sounds
b = with systemic signs
What is paraneoplastic syndrome?
systemic effects of a tumour, occouring at sites distant to the tumour
- result of a secretion of a hormone or hormone-like subsance, enzyme, cytokine, immune mediated mechanisms
What 4 baseline tests can be used to assess the cancer patient?
- haemotology/blood count
- Biochem
- Urinalysis
- COaglation parameters (when indicated)
WHat can haemotology/complete blood count show?
- general health status
- baseline before starting chdemo
- check for
> anaemia
> cytopenia
> abnormal cells in circulatin
What can biochemistry show?
- general health status
- organ damage and function esp prior to GA and chemo
- liver and kidney parameters
3 common paraneoplastic effects
- Hypercalceamia due to tumour production of PTH-rp -> renal damage
- Hypoglyceamia due to secretion of insulin or insulin like growth factor
- Hyperglobulinaemia due to excessive AB production
What does urinalysis show?
- underlying renal and other diseases
- do dipstick, sediment and SG
Clinical signs associated with hypercalcaemia?
- PUPD
- depression
- anorexia
- weakness
- bradycardia
Clinical signs associated with hypoglyceamia>
- weakness, collapse
- seizures
Clinical signs associated with hyperviscosity?
due to hyperglobulinaemia and polycythaemia
- neuro signs
- seizures
- retinal detachment
Which tumours are associated wth gastric ulceration and vomiting?
mast cell tumours -> histamine release
gastrin secreting tumours
Clinical signs associated with endocrine problems?
- hyperadernocorticism (pituitary and adrenal)
- hyper/hypo thyroid
- acrogmegaly (excess IGF1 pituitary adenoma cats)
- feminisation (sertoli cell tumour)
- hypertension (phaeochromocytoma)
- hypercalcamia (excess PT Hor PTH-rp)
What paraneoplastic effect may thymoma have?
Immune mediated diseases
- IMHA
- IMT
- polyarthirtis
- polymyositis
- myasthenia gravis
What is hypertrophic osteopathy?
lameness and swelling of long bones
- periosteal new bone on the shafts of long bones associated with intrathoracic masses
Which paraneoplastic effects may manifest in the skin?
endocrine, immune mediated
Why does cancer cachexia occour?
Reease of cachexic factors from tumours
What i a myeloma?
Plasma cell tumour
-> hyperglobulinaemia and thickened blood
What are the 7 main cancer treatment options?
- surgery
- radiation
- chmo/cytotoxic drugs
- molecular targetted drug therapy eg. tyrosine kinase inhibitors
- anti-angiogenic therapt (metronomic low dose therapy)
- immunotherapy eg. melanoma DNA vax
- others eg. photodynamic therapy, electrochemotherapy, bisphosphonates
What health and safety points should be remembered with chemotherpay?
can be carcinogenic, mutagenic and teratogenic
- pregnant women and children should not handle the drugs or body fluids from people on chemo
- do not crush tablets
- dispense in child proof container always
- injectables should be drawn up in a sealed area or Phaseal unit
- work over absorbant pad in case of spillage
- double glove and wear waterpoorf protective gear
- use luer-locking syringes not push on
- double bag excreta and wear protective clothing when cleaning up urine from animals for a couple of weeks
- dispose as cytotxic waste
- no contact with saliva
What is the main cell type in an injection site sarcoma?
Fibroblast
How is an injection site sarcoma defined histologically?
Neoplasia surrounded by inflammation
How does inflammation cause neoplasia?
Transforming growth factor released by cytokines breaking down ECM
- cats must be predisposed to developing tumours
What is a sarcoma?
Malignant mesenchymal cell tumour
Are ISSs painful?
No unless growth rate so high that ulceration occours
Why may ISSs grow so rapidly?
Become cystic and blow up
What is always necessary for Dx of ISS?
CT
What is the first test to do on a suspected ISS?
Cytology by FNA
Should excisional or incisional biopsy be performed on ISSs?
Incisional
- once scar is present must be included as part of tumour and any future margins must be in relation to scar
What margin is necessary when removing a tumour?
3-5cm
- if 3 still need radiation
2 fasical planes below the tumour (may be associated with spinous processes so may have to remove)
What is the DDx for ISS? When should you suspect ISS?
Granuloma
- 321 rule
- present for 3 months, bigger than 2 cm or grows within 1 month = need to biopsy
What isthe median survival time of ISS with no surgery?
3 months
What do whiter and darker areas of a mass on CT indicate?
Whiter= vascularised Darker= cystic or necrotic
What should be done prior to durgery if the mass is too large to remove?
Radiation or chemo
Guidelines for preventing ISS severity?
- rotate injection sites around the legs or tail base (easy to amputate if tumour occours)
- record where you vaccinate
- dont over vax
- try to use non-adjuvant vax
