Skin and Subcutaneous Tumours: Mast Cell Tumours Flashcards
How many of dog neoplasms are in the cutaneous?
25-30%
What % of cutaneous tumours are benign vs malignant
70 % vs 30%
Mean age of cutaneous tumour presentation?
8.3 years
Where are majority of cutaneous tumours on the dog?
Trunk (30%), head and neck (20%) and extremities (19%).
How many of cat neoplasms are cutaneous?
10%
What are the 4 common cutaneous neoplasia in cats?
Basal cell tumour
Mast cell tumour
Squamous cell carcinoma
Fibrosarcoma.
What tissue is involved in cutaneous tumours?
Skin or subcut
How are cutaneous tumours broadly classified? (5)
- Epithelial
- Adnexal
- Mesenchymal
- Round Cell
- Melanocytic
Epithelial cutaneous tumour examples (4)
- Basal cell tumours
- Papilloma
- SCC
- Nail bed tumours
Adnexal cutaneous tumour example (7)
- Sebaceous gland adenoma/adenocarcinoma
- Ceruminous gland adenoma
- Apocrine gland adenocarcinoma of anal sac
- Sweat gland tumours
- Trichoepithelioma
- Pilomatrixoma
- Meibomian gland adenoma
Mesenchymal cutaneous tumour example (1)
Soft tissue sarcoma
Round cell cutaneous tumour example (5)
- Mast cell tumour
- Histiocytoma
- Melanocytic nevi
- Plasmacytoma
- Lymphoma
Mealoncytic cutaneous tumour example (2)
- Benign cutaneous melanocytic nevi
- Malignant melanoma
What should happen to ALL skin/subcut masses prior to surgery?
FNA
When is pre treatment biopsy indicated? (4)
-If the tumour type will alter the type of treatment;
- If the histological grade of the tumour will alter the extent, surgical dose or treatment;
- If the tumour location limits the reconstructive options;
- If the tumour type and grade affect the owner’s willingness to pursue treatment based on prognosis.
How many of dog malignant cutaneous tumours are MCT?
20%
How common is cutaneous MCT tumour in cat?
2nd most common
Where can MCT arise from? (2)
- dermal
- sub cut
What do the characteristic cytoplasmic granules of MCT contain? (5)
- Histamine
- Heparine
-Proteases
-Chemotactic factors
Cytokines.
Dog age MCT?
Middle age - 5yr +
Breeds more commonly seeing MCT? (6)
Boxers, Boston Terriers, Golden Retrievers, Labrador Retrievers, Beagles and Schnauzers
Which breed is more likely to have multiple MCT at time of diagnosis? What is the behaviour of these?
Pugs
- more benign
How many MCT:
A) Occur on trunk?
B) on limbs?
A) 50-60%
B) 25%
The majority of MCTs will be diagnosed on cytology following FNA. The typical path of metastatic spread is initially to the A) and then to B) liver or bone marrow. Cutaneous MCTs rarely metastasise to the C)
A) Regional LN
B) Spleen
C) lungs
What does staging of a MCT involve? (3)
Local tumour FNA
Regional lymph node aspirates
Abdominal ultrasound
Should we aspirate spleen/liver when staging MCT?
not routinely recommended
What is the general behaviour of a eyelid MCT?
Relatively benign