Ocular Flashcards
What is the most common eyelid tumour in cats?
SCC
What’s the most common malignant tumour of the canine conjunctiva?
melanoma
What are the most common tumours of the canine conjunctiva/ eyelid?
- sebaceous/ meibomian adenoma
- epithelioma
- papilloma
- melanoma
(the above accounts for 80%)
even if malignant, tend to be localized
What’s the most common tumour of the feline eyelid?
SCC
What’s the most common tumour of the3rd eyelid in the cat/dog?
adenocarcinoma
can spread to the lymph nodes and lungs
How important in resection margin for conjunctival MCT?
even if incomplete, it may not recur
How much eyelid can be surgically removed?
dogs: 1/4-1/3
cats: 1/4
don’t do electrosurgery due to excessive scarring
What’s the prognosis for canine primary eyelid tumours?
overall good
- metastasis is rare
- could recur (10-15%) –> esp for conjunctival melanoma, adenocarcinoma
What’s the prognosis for feline primary eyelid tumours?
they are mostly malignant so prognosis is not as good as the dog
What are some differentials for limbal melanoma?
conjunctival melanoma, invasive uveal melanoma, metastatic malenoma, staphyloma, or coloboma
What’s the prognosis of epibulbar melanoma?
good
typically benign and slow growing
surgery +/- beta irradiation = curative
enucleate if invading the globe
What are some features of malignancy for ocular melanoma?
MI >/= 4 per 10hpf, increased nuclear atypia
metastatic rate = 4%
How common in primary malignant melanoma of the eye in the dog?
majority of intraocular melanoma are benign (75%)
95% arise from the ciliary body
What’s ocular melanosis of Cairn Terriers?
it’s an autosomal dominate disease
thickening and pigmentation of the iris
release of pigmentation into the aqueous –> secondary glaucoma
What are some clinical signs of primary ocular tumours?
hyphema
glaucomaWhat
How to treat primary ocular tumours?
- monitor
- consider removal of the tumour (surgery or laser) if causing issues
- don’t need to enucleate right away
What’s the prognosis of primary ocular tumours?
Historical data:
metastatic rate of 25% within 3m of enucleation and MST of 6m (malignant melanoma)
More recent data:
likely better than that.
Enucleation (early on) = curative
even if some black tissues are left behind it won’t grow
What’s the most common tumour of the feline anterior uvea?
melanoma
What’s the metastatic rate for feline malignant intraocular melanoma?
55-66%
lungs, liver
What are some features that will increase the metastatic rate of feline intraocular melanoma?
- increased MI >7/10 hpf
- necrosis
- extrascleral extension
- size
- choroid invasion
- increased E-cadherin or melan-A
(PLN-2 homozygosity DECREASES met rate)
malignant transformation possible – may take a long time, hard to predict
What’s the prognosis of feline diffuse iris melanoma?
Sx:
MST with ciliary body involvement = 5y
MST with sclera involvement as well = 1.5y
secondary glaucoma will decrease survival time
What are some tuours types for feline ocular post traumatic sarcoma?
spindle, round (LSA, CD79a positive), OSA/CSA
What’s the clinical behaviour of feline ocular post traumatic sarcoma?
can have latency up to 5 years
- tend to invade retina and optic nerve early on
- early enucleation improves prognosis
- recurrence = common as extra orbital invasion is common
What’s the outcome of feline ocular post traumatic sarcoma?
Survival is typically months once the eye is enucleated due to recurrence or local invasion
What’s the 2nd most common tumour in the dog’s eye/ 3rd most common in the cat?
iridociliary epithelial tumours
- most are benign, slow growing
- even if malignant, metastasis is uncommon and occurs late in the disease
What are some differentials for iridociliary epithelial tumours?
benign ciliary cyst
- biopsy alone may not be able to ddx between benign cyst and adenocarcinoma
- recurrence is possible (23m)
What are the most common secondary uveal tumours in the dog?
LSA > histiocytic sarcoma > hemangiosarcoma > respiration carcinoma > digital/ oral melanoma > OSA > SCC
uveal tract = highly vascular
What are the most common secondary uveal tumours in the cat?
LSA > respiratory carcinoma > SCC
What’s the outcome of canine primary ocular LSA?
majority was enucleation alone
MST = 769 days
if multicentric, MST = 103 days
What’s the outcome of canine histiocytic sarcoma of the eye?
ST = 3 months
What’s the most common primary optic nerve tumour?
meningioma
What are some secondary optic nerve tumours?
- feline post traumatic ocular sarcoma
- feline SCC
- canine choroidal melanoma
Is primary orbital tumour more common in the dog or the cat?
dog
cats more commonly have secondary orbital tumours
for both species, 90% of orbital tumours are malignant – regional infiltration or distant metastasis is common
What are some common orbital tumours in the dog?
OSA, MCT, HS, FSA, neuro FSA
What are some common orbital tumours in the cat?
2/3 carcinoma – mostly SCC
What’s the clinical behaviour of canine orbital meningioma?
slow growing, rarely met
can be osteolytic and invade
What’s the clinical behaviour of canine orbital rhabdomyosarcoma?
- aggressive, esp if <1y, euthanize within 1 month
- better if > 6 y, less aggressive, no recurrence or met 8-13 months
What are some clinical signs of orbital tumours?
pain on opening of mouth
exophthalmos
vision loss
What are some differentials for orbital tumours?
granuloma, cellulitis, abscess, myositis of extraocular or masticating muscles
What’s the clinical behaviour of feline orbita tumours?
59% orbital bone involvement;
15% with mets on CXR
What’s the diagnostic value of FNA for orbital tumours?
50% of FNA = non diagnostic, esp for SCC
How is orbital tumour treated?
surgery, but recurrence is still possible even with a big cut
What’s the outcome with radical orbitectomy?
DFI > 1y in > 50%
70% survival in 1 year
but in another study with cats the MST was only 4.3m… and one more study with dogs only had 3/23 survive more than 3y
What’s the outcome of Sr 90 for eyelid SCC in cats?
- 100% RR
no signs of recurrence with a median follow-up time of 34 months
Strontium 90 plesiotherapy for the treatment of eyelid squamous cell carcinoma in eight cats. Russak et al 2022
What’s the outcome of ocular dermoids in cats?
Sx had no recurrence
What’s the most common retrobulbar mass in cats?
LSA (51%)
most cat retrobulbar mass = malignant
What are some common clinical signs of retrobulbar mass?
- respiratory signs (62%)
- exophthalmos (49%)
