Skin Tumors Flashcards
Most common feline skin tumors (4)
- SCC
- trichoblastoma (basal cell tumor)
- injection site sarcoma
- MCT
You should NOT “wait and see” about a skin lump if:
- present >1 month
- >1cm
- ulcerated/bothersome of pet
If you find a cutaneous mass, what are some first steps you should take?
- measure w/ calipers
- body mapping
- aspirate
What size of masses are typically suitable for excisional biopsy?
< 3 cm
When is an incisional biopsy suitable?
- large tumors
- staging malignant tumors
Skin melanomas aren’t especially prone to metastasis, but possible sites of metastasis are:
- regional lymph nodes
- lungs
- liver
- meninges
- adrenal glands
What is a fairly good “rule” about melanoma of haired skin?
generally benign
What is a suitable treatment for melanoma on haired skin?
- Sx-1 cm margins & 1 fascial plane; submit for histopathology for margin eval and to determine mitotic index
Rank the prognosis for oral, skin, and digital melanoma from best to worst
skin, digital, oral
Recommended staging tests for digital melanoma
- cytology draining LN
- 3-view radiographs +/- abdominal US
What % of cases of digital melanoma metastasize?
30-40%
If a digit amputation is done for a digital melanoma that staged clean, how many dogs are alive after 2 years?
<15%
Biological behavior of oral melanoma
- very locally invasive
- high metastatic potential
Treatment for canine oral melanoma
- surgery and/or RT + adjuvant systemic therapy (e.g. chemo, vaccine)
21% of canine skin tumors are ______
mast cell tumors
High risk breeds for MCT
- Boxers
- Bulldogs
- Boston terriers
- Labradors
- Shar pei—usually a highly malignant variant
Mast cell degranulation can result in:
- Dariers’s sign
- GI ulceration
- Hypotension, shock
- coagulopathies
- wound dehiscence
How is MCT grade determined?
via histopathology only
What is the purpose of thoracic radiographs when dealing with MCT?
not to look for pulmonary metastases, but to allow for evaluation of sternal lymph nodes as the regional lymph node if the MCT is in the cranial part of the body
What is the proper “surgical dose” for MCT removal?
wide excision
Up to ____% of patients with low grade MCTs removed with confirmed clean margins develop additional cutaneous MCT
11%
What is the role of hypofractionated RT in MCT treatment?
- palliation of bulky MCT; alone or in combination with Palladia
What is the role of full-course RT in MCT treatment?
- often locally curative for incompletely excised MCTs in dogs
- can be used for local control of bulky dz when Sx is not an option
What is the role of conventional chemo in MCT treatment?
- adjuvant therapy for high grade II and grade III MCT; may help decrease risk of metastasis and help survival
