Module 10 Flashcards
(48 cards)
Ocular neoplasia - eyelid
Dog 75% benign average age 8, cats 90% malignant average age 10
Dogs: sebaceous adenoma, papilloma, benign melanoma, sebaceous adenocarcinoma
Cats: SCC, MCT, haemangisarcoma, adenocarcinoma, lymphoma
Sx excision advised, although cryo, hyperthermia, laser CO2 ablation also used.
FNA or snip bx beforehand preferable
Only exception is when dog presents with signs typical of adenoma
All should be sent for histo by ocular pathologist
1/3 eyelid length can be removed, four sided wedge. closure 6/0 polyglactin. Figure of 8 at margin.
>1/3 will need reconstructive procedures
Ocular neoplasia - eyelid
CANINE
Sebaceous adenoma/adenocarcinoma: 40% of eyelid masses, affects meibomian glands and seen erupting through eyelid margin or conjunctiva behind margin. Block duct opening –> chalazion, if granulomatous reaction 5-7 days ABs and NSAIDs prior to sx. Small proportion adenocarcinomas - benign in nature
Papilloma: 10-20% eyelid tumours, viral in origin. Pendunculated, verrucose, greyish colour. May regress in young dogs. sx resection and cryo to avoid recurrence.
Melanoma: eyelid skin or margin, single or multiple. Benign. sx excision curative
Histiocytoma: young dogs, smooth pink hairless appearance. Dx FNA. 6weeks to 10months to regress. sx if do not regress within 3 months.
Ocular neoplasia - eyelid
FELINE
SCC: UV light part of pathogenesis, white cats. Raised or depressed ulcerative lesion. Mets late in the dz but can be extensive and regional LNs. Wide margins required with grafting procedures. Radiation, cryo and photodynamic tx follow up.
MCT: the great pretender, older cats, variable appearance, cuteanous MCT tends to be benign in cats, sx or strontium 90 plesiotherapy
Haemangiosarcoma: complete excision likely to be curative. poss UV associated
Adenocarcinoma: aggressive, incomplete excision –> death or PTS
Lymphoma: uncommon in this location but carrier poor prognosis
Apocrine hidrocystoma: cystic adenomas of apocrine sweat glands (glands of Moll), single or multiple smooth round fluid filled lesions, 2-10mm in skin of eyelid especially around medial canthus. Blue/grey appearance. Persians. Sx difficult and recur, drainage and cryo or leave since cosmetic.
Peripheral nerve sheath tumour: spindle cell neoplasms, arise from peripheral cranial or autonomic nerves. Upper eyelid mostly. Aggressive local recurrence so wide excision with exenteration is advised.
Tumours of conjunctiva
Uncommon, snip bx under topical LA
Primary:
- Dogs: MCT, SCC, papilloma, haemangioma/sarcoma, melanoma, fibroma/sarcoma
- Cats: SCC, haemangioma/sarcoma, melanoma, peripheral nerve sheath tumours, Hodgkin’s like lymphoma
Secondary:
- Dog: Lymphoma, systemic histiocytosis, haemangioma/sarcoma, adenoma/carcinoma, MCT, TVT
- Cat: lymphoma, haemangioma/sarcoma, adenoma/carcinoma
Tumours of conjunctiva
CANINE
Dogs - apart from melanoma conj tumours are benign. SCC locally aggressive, melanoma has predilection site for TEL and is malignant in this location and mets
Conj MCTs - benign.
Conj haemangioma/sarcoma - superior temporal bulbar conjunctiva, leading edge of TEL. Linked to UV light. Sx may be curative, adjunctive txs prevent recurrence
Papillomas - young dogs, can regress spontanously
Lymphoma - conjunctival thickening, part of systemic neoplastic progress
Tumours of conjunctiva
FELINE
SCC - extension of eyelid mass, or TEL conj.
Conj melanoma - bulbar conj, majoirty pigmented but some amelanotic, aggressive, mean survival time 11 months.
Tumours of the cornea and sclera
*SCC: D+C. very rare. Pink multilobular mass secondary to corneal irritation and UV light, brachys and chronic topical steroids. Tx: keratectomy. Adjunctive approach - cryo, strontium 90 irradiation, CO2 laser, topical mitomycin C.
- Corneal papilloma - D
- haemangiosarcoma - D+C.
*limbal melanoma: D+C - arises at limbus, smooth pigmented elevated subconjunctival masses at limbus, may extend into cornea. Rarely amelanotic. Benign - GSDs, labs, golden retrievers. Young dogs 2-4: rapidly expansive. Older dogs 8-11: relatively static. Young dogs - surgical excision is advised. Differentiate from outward extension of uveal melanoma. ocular exam, gonio and US. Grafting often required. Adjunctive tx to resection may reduce risk of recurrence. Cryo, strontium 90B plesiotherapy.
Very occasionally reported in cat.
Uveal tumours
Dog:
- primary: melanocytic, iridociliary, adenoma/adenomcarcinoma, medulloepithelioma
- secondary: Lymphoma, histiocytic sarcoma, haemangioma/sarcoma, adenocarcinoma
Cat:
- primary: feline diffuse iridal melanoma, feline post traumatic ocular sarcoma, iridociliary, adenoma/adenocarcinoma
- secondary: lymphoma, SCC, haemangiosarcoma, adenocarcinoma, fibrosarcoma
Canine Uveal Tumours - Melanocytic tumours
Melanocytic tumours: most common primary IO tumour in the dog, arise from iris or ciliary body, rarely from choroid. Older dogs ~9. GSDs and golden retriever breeds. 80% benign but slowly progressive and secondary glaucoma may occur.
Malignancy: nuclear pleomorphism, prominent nucleoli, higher nucleus:cytoplasm ratio, >2 mitotic figure per high power field. Small number amelanotic. Nodular rather than diffuse as seen in cats.
Slit lamp examination, gonio and US
20% malignant, but very small number metastasis haematogenously to thorax and abdo.
Tx: small masses on pupillary margin may be operable. Diode laser cyclphotocoagulation is another tx option. If visual monitor and enucleation if signs of ongoing inflammation or glaucoma. Histopathology ALWAYS.
Canine uveal tumours
iridociliary adenoma/carcinoma: second most common primary canine IO tumour, arise from epithelium of iris or ciliary body. Pigmented or non-pigmented masses, protruding through or distorting pupil. Older dogs
*adenoma:adenocarcinoma is 50:50 - distant mets with latter reported but is unusual
medulloepithelioma: tumour of primitive neuroectodermal origin, young dogs, white or grey masses within the pupil or extending through iris. Some may contain abnormal tissue (Teratoid medulloepithelioma). Benign.
Feline Uveal Tumours - Feline diffuse Iridal Melanoma
Most common IO tumour of the cat, progressive pigmentation over months to years. Iris become thicker, loses architecture, changes in pupil shape or mobility may occur. Blockage of drainage angle and secondary glaucoma may be seen. Can be amelanotic. metastatic rate 63% - liver or lungs and may occur as late as 1-3 years post enucleation
Benign lesions can metastasise later so FNA useless.
Salient features: change in iris architecture, free-floating pigmented cells in anterior chamber, pupil abnormalities, mass, total iris colour change, uveitis or secondary glaucoma, tumour within the drainage angle on gonio (once tumour enters drainage angle and scleral venous plexus risk of mets high)
prior to enucleation 3 views of chest, and abdo US advised. If extends through sclera then exenteration is advised.
Feline Uveal Tumours - Feline post traumatic ocular sarcoma
Highly malignant tumour of cats with previous ocular trauma, ~6.2years post trauma.
Three variations:
1) spindle cell variant (most common and most aggressive)
2) round cell variant (lymphoma)
3) osteosarcoma/chondrosarcoma (least common)
Lens capsule rupture major risk factor. As well as: chronic uveitis, IO surgery, intravitreal gent inj.
Presentation: intractable uveitis, glaucoma, IO haemorrhage, previously phthisical globe which begins to enlarge.
Tx: enucleation and exenteration of orbit. Many die within a few months of related causes even after sx. Px by enucleating blind traumatised globes of cats.
Uveal Tumours - canine and feline
lymphoma
Third most common IO neoplasm in dogs, second most in cats.
Generalised lymphadenopathy.
Ocular signs: infiltration of iris stroma with neoplastic, accumulation of neoplastic cells in the anterior chamber (pinkish colour), hyphaema (paraneoplastic phenomenon).
Cats - uveitis, nodular masses, diffuse infiltration of the anterior uvea.
Retina +/-subretinal infiltrates.
Dx - neoplastic cells on cytology or histo. LNs, organs or the aqueous humour (CCS will mask dx).
Orbital tumours
90% malignant. Presented late. >8years. Mostly secondary.
Dogs and cats:
*Primary: osteosarcoma, fibrosarcoma, chrondrosarcoma, myxosarcoma, neurofibrosarcoma
*Secondary: lymphoma, SCC, melanoma, adenocarcinoma, cerebral meningioma
Unilateral exophthalmos, resistance to retropulsion, unlike orbital cellulitis or abscess less pain on opening mouth. However osteolytic tumours will be painful. Lagophthalmos, secondary desiccation of cornea and corneal ulceration.
DX: rads, US, CT, MRI. Tru-cut bx more useful than FNA. Survey rads (if systemic may be important to do this first and prevent expensive and lengthy work up)
Tx: dependent on tumour type. Palliation likely only possible tx. Exenteration or orbitotomy may be considered but mostly PTS.
Systemic conditions with ocular manifestations
Developmental dz: lysosomal storage dz
Lysosomal storage dzs - rare inborn errors, caused by deficiency in specific enzymes, accumulation or metabolic by-products, within lysosomes. autosomal recessive. Progressive neuro signs –> death or PTS.
- Ceroid Lipofuscinosis - retinal dz and central blindness, Tibetan terrier, PON
- Fuscosidiosis - visual defects, ESS
- globoid cell dystrophy - C & D - lack of vestibulo-ocular reflex, visual deficits, WHWT, Cairn terrier, Irish setter
- GM1-gangliosidosis - C & D - corneal opacities, retinal lesions, strabismus, Husky, ESS, portuguese water dog, shiba inu, korat, siamese
- GM1-gangliosidosis - C & D - visual deficits - german short-haired pointer, toy poodle, golden retriever, burmese, korat
- mucopolysaccharidosis - D & C - corneal opacities , various breeds
- alpha-mannosidosis - corneal opacities, lens opacities, nystagmus - persian
- mucolipidosis II - cats - facial abnormalities, visual deficits, retinal dz
- Sphingomyelin lipidosis - cats - blindness, nystagmus
Systemic conditions with ocular manifestations
Developmental dz: Ehler’s Danlos Syndrome
Collagen defects, inherited autosomal dominant.
Skin is hyperextensible and easily torn.
Other signs: abnormal limbus, clouding of cornea, thin sclera, bilateral cataracts, lens luxation
Dx: CS and extensibility index - extending skin fold over dorsal lumbar area maximally and dividing by body length and multiplying by 100. >14.5% significant
Systemic conditions with ocular manifestations
Developmental dz: Chediak-higashi
autosomal recessive cats - persian Partial albinism Bleeding tendencies Pale irides, retinal hypopigmentation, tapetal degeneration, cataracts, nystagmus
Systemic conditions with ocular manifestations
Developmental dz: keratoconjunctivitis sicca and ichthyosiform dermatosis (KCSID)
CKCS - dry eye and curly coat syndrome.
autosomal recessive.
Rough and curly coated puppies with progressive skin signs - scaliness of the flanks and dorsum, harsh coat, alopecia, hyperkeratosis of the footpads.
Dry eye present very early
Tx: symptomatic, lacrostimulants have little effect, frequent lubrication.
Caution secondary ulceration.
Genetic test available
Systemic conditions with ocular manifestations
Developmental dz: oculo-skeletal dysplasia
Samoyed and labrador
Abnormal growth and development of bones and cartilage, short legged dwarfism and ocular lesions; retinal dysplasia and retinal detachment
The complete phenotype is inherited as an autosomal recessive trait
Intermediary forms, mode of inheritance may differ
Systemic conditions with ocular manifestations
Metabolic dz: Diabetes
- insufficient insulin secretion from B cells in islets of langerhans of the pancreas
- Risk factors are genetic, obesity and prior pancreatitis
- Cataracts formation, lens induced uveitis, endothelial changes, reduced corneal sensitivity, lowered tear production, retinal vascular damage.
- 75% cataracts within 6 months dx, 80% within 16 months
- excess glucose–> sorbitol by aldose reductase. Sorbitol causes osmotic gradient which pulls water in, swelling/intumescence and alteration in lens proteins. Suture lines appear widened - water clefts.
- Phacolytic uveitis; IO inflammation caused by altered lens proteins leaking through capsule into anterior chamber, perceived as foreign by immune system
- Older cats have less aldose reductase and hence less likely to develop cataracts
- Reduced STT and lower TFBUT.
- reductions in goblet cells and conjunctival dysplasia
- 21% retinal signs - venous dilation, vascular tortuosity, sacculation, microaneurysms, haemorrhages, alterations in tapetum.
Systemic conditions with ocular manifestations
Metabolic dz: HAC, hypot4,
Cushing’s. Pituitary depends, adrenal cortex dependent, iatrogenic
PUPD, pendulous abdo, hair coat changes, thinning skin.
Ocular signs: corneal ulceration with protracted healing, corneal calcification, KCS, lipaemia retinalis, lipaemic aqueous.
HypoT4. immune-mediated destruction of thyroid gland. Wt gain, lethargy, PD, bradycardia. Ocular signs: KCS, hypertensive retinal changes, hyperlipidaemia (lipaemia retinalis), lipaemic aqueous, corneal lipid deposits (arcus - adjacent to limbus classic). CN VII paresis/paralysis, vestibular dz, nystagmus
Systemic conditions with ocular manifestations
Metabolic dz: hyperparathyroidism/secondary nutritional, hyperT4
Hyperparathyroidism/secondary nutritional hyperPTH. hypoca, focal cataracts in anterior and poster lens cortices. Correction of the underlying hypoca will not resolve nor prevent further development of focal lesions
HyperT4. cats, systemic hypertension which leads to classic fundic signs,
Systemic conditions with ocular manifestations
Nutritional dz:
Milk replacer cataracts - arginine deficiency. noted at 3 weeks of age within fetal nucleus. Do not progress or cause blindness
Taurine deficiency - sulphur containing amino acid. DCM as well as FCRD (feline central retinal degeneration). granular appearance to tapetal fundus, hyperreflective lesions in area centralis, similar lesions on nasal side, then coalesce horizontal to ONH. Eventually entire retina. Believed taurine protects photoreceptors. Plasma <40nmol/L indicative.
Thiamine deficiency - cats fed raw fish with thiaminases or severe GI dz –> malabsorption, neuro signs, fixed dilated pupils, ONH vascularisation, peripheral retinal haemorrhage. CS, low blood thiamine (norm <32ug/dL)
Systemic conditions with ocular manifestations
Nutritional dz:
Vitamin E deficiency: anti-oxidant role in limiting free radicals. phagocytosis of photoreceptor phospholipid membranes produces autofluorescent yellow-brown pigment. deficiency of a-tocopherol –> accumulation of pigment, identical to RPED. Visual defects but not usually lost completely. Poor diets but ECS have familial vit E deficiency, who will also exhibit neuro signs. Supplementation reverses neuro signs, halts ocular signs.
Dx - fasting a-tocopheral levels measured. 600-900IU natural a-tocopherol BID
