Skin, Ears and Toes Flashcards
What are the four most common skin and SQ tumors in cats?
Basal cell tumors, MCT, SCC and fibrosarcoma
Papillomaviruses are only able to replicate in _____ cells
terminally differentiated cells
What are the two main viral proteins from papillomavirus that lead to neoplastic transformation? What do that interact with?
E6 - destabalizes p53 E7 - inhibits pRB
Disruption of p53 by papillomavirus protein can cause increased levels of ____ which is detectable with IHC
p16
Canine papillomavirus has been associated with the development of ______
SCC - usually cutaneous
What are PPVs associated with in cats?
Viral plaques - aka feline sarcoids
PPV can be detected with IHC in most feline plaques - as the plaques progress to SCC, the ability to detect PPV ag increases/decreases
Decreases
PPV is detected in more UV-protected or UV exposed areas of SCC in cats
UV-protected - up to 76% vs. 42% of UV exposed
Basal cell carcinoma in people is thought to arise from critical mutations in what signaling pathway
Hedgehog
What aberrant karyotypes have been found in feline basal cell tumors
Trisomy E2 and monosomy E2 - unknown significance
____ staining is considered fairly specific for human BCC and was detected in 23/24 BCC in cats in one study
Bcl-2
The presence of detectable ____ with IHC indicates mutations in the coding sequence and has been associated with what cutaneous tumor in cats and dogs
p53; SCC
What does p27 do? What cancer type has lower levels of this compared to benign tumors?
protein thought important in maintaining cells in G0 SCC
Nuclear activation of beta-catenin was detected in 100% of what skin tumor(s)
trichoepitheliomas and pilomatricomas
Which cyclin is expressed in the majority of feline SCC and just under half of canine SCCs
cyclin A
What is the causative mutation causing renal cystadenoma and nodular dermatofibrosis?
Birt-Hogg-Dube (BHD) gene
What does the BHD gene code for?
Tumor suppressor protein folliculin
What TKI has been associated with the rapid development of actinic keratosis and invasive SCC in people? What does this TKI inhibit?
Sorafenib - inhibitor of RAF and VEGF/PDGFR
What markers are used to differentiate BCC from SCC in people
epithelial membrane protein BerEP4
What dog breeds are at an increased risk for BCC
cocker spaniels, poodles
What are the three histologic subtypes of BCC in dogs
solid, keratinizing and clear cell
What is the behavior of BCC in dogs?
Low-grade malignancy; can recur but no reports of mets
Where does BCC most commonly occur on cats?
Head and neck - can be pigmented, too!
In patients with multiple papillomas, what drug may be effective
azithromycin
What is actinic keratosis in cats?
SCC in situ that arises as a consequence of UV exposure (different from Bowens based on location and histo)
Median DFI and MST for cats treated with surgery for a single nasal planum or pinna SCC?
DFI 594d, MST 675d
What cream can be used to treat Bowens in cats?
Imiquimod 5%
What topical cream was NOT effective for Bowens in cats
13-cis-retinoic acid
For cats treated with photodynamic therapy for bowens, what is the response rate and what is prognostic?
RR up to 100% (used in people too) Clinical tumor stage
What breeds of cats are at a DECREASED risk of SCC
Siamese, Himalayan and Persian
What dog breeds have a predisposition for nasal planum SCC?
Labs and goldens
what dog breeds are predisposed to cutaneous SCC
Poodles, bassets and blood hounds
What paraneoplastic syndrome has been associated with cutaneous SCC in cats?
Hypercal - two had ear canal tumors, the other had multiple cutaneous tumors
ECT with bleo for cats with cutaneous SCC has what CR rate and what survival range?
CR in 82%; survival 2mo - 3yrs
What breeds of dogs are more likely to ket infundibular keratinizing acanthomas (IKAs)
Nordic breeds - Norwegian elkhouds, belgian sheepdogs, Lhasa apso, German Shep
Surgery is the treatment of choice for IKA but what is an alternative option?
Isotretinoin (vitamin A derivative)
Malignant trichoepitheliomas are also called____
matrical carcinoma
What is the behavior of malignant trichoepithelioma?
Rare and only case reports but reports = highly metastatic to regional LN and lungs
What breeds are more likely to get pilomatricomas
Kerry blue, soft-coated wheatens, Bouvier, poodles, sheepdogs, bichons, Airedales
What is the behavior of malignant pilomatricoma
High metastatic potential - mets to lungs, bone, LN, mammary gland or skin in 11/12 dogs in one report
What cutaneous tumors have adenxal differentiation? What does this mean
Arise from hiar follicle IKAs, tricholemmoma, trichoblastoma, trichoepithelioma, malig. trcihoepithel (matrical carcinoma), pilomatricoma/malignant pilomatricoma
Where is the most common site for apocrine gland carcinoma in dogs?
Thoracic limbs
What is the prognosis for apocrine gland carcinoma
Highly invasive, but cure rates high with surgery alone
What is an eccrine adenoma/carcinoma
tumors of the sweat glands of the footpads
What is the other name for neruoendocrine carcinoma
Merkel cell carcinoma
What is the behavior of Merkel cell tumors in people? How does this compare to dogs and cats?
Highly malignant in humans; case reports in cats and dogs suggest more benign clinical course
Loss of expression of what proteins is linked to a more aggressive behavior in humans for Merkel cell tumors has also been found in dogs
E-cadherin, beta-catenin
What do most dogs with nodular dermatofibrosis die from and how long does this usually take?
Renal failure from renal cystadenocarcinoma, average 3 years