Cutaneous masses Flashcards
1
Q
Swellings of non-dermatologic origins
A
▪ Hernias
▪ Oedema
▪ Bursitis
▪ Emphysema
▪ Mammary tumours
2
Q
Types of skin masses
A
- Inflammatory (infectious & non-infectious)
- Neoplastic
- Hyperplastic/dysplastic
- Cyst
3
Q
Examples of infectious (septic) skin masses
A
- Bacterial infection
- Fungal infection
- Protozoal infection
- Demodex
4
Q
Examples of non-infectious (sterile) skin masses
A
- Urticaria/angioedema
- Eosinophilic granuloma
- Arthropod bite granuloma
- Sterile panniculitis
- Haematoma Seroma
5
Q
Investigating a skin mass
A
▪ Signalment
▪ History – general, dermatological
▪ Clinical examination – general, dermatological
-> Formulate list of ranked d/ds
-> Investigate d/ds using
– Cytology – usually FNA
– Tissue biopsy
-> histopathology
-> + tissue culture if inflammatory
6
Q
FNA cytology of an inflammatory mass - what do you see?
A
▪ Predominant inflammatory cell type?
– E.g. Neutrophilic? Eosinophilic? Pyogranulomatous?
▪ Sterile vs septic
– Evidence of organisms?
-> Some need special stains (e.g. mycobacteria)
inflammation
–NB Cannot assume sterile if no organisms seen, pften need further diagnostics (e.g. tissue culture, PCR)
– Non-degenerate vs degenerate neutrophils
7
Q
FNA cytology of an neoplastic mass - what do you see?
A
▪ Round cell vs epithelial vs spindle cell
8
Q
FNA cytology of a cyst - what do you see?
A
▪ Contents produced by cyst’s epithelial lining – e.g. sebaceous or keratinized material/squames. Often amorphous appearance.
Sometimes cholesterol crystals
▪ +/- secondary inflammation if cyst ruptures
9
Q
What non-infectious inflammatory masses are associated with mast cell degranulation?
A
- Urticaria
- Angiogenic oedema
10
Q
What non-infectious inflammatory masses are associated with degenerated collagen?
A
- Eosinophilic granuloma (especially cat)
- Arthropod bite granuloma
11
Q
What non-infectious inflammatory masses are associated with fatty-acids / lipids
A
- Sterile panniculitis, various causes:
– Traumatic
– post-injection (‘injection reaction’)
– nutritional
– foreign material
– sterile nodular (idiopathic) - Xanthoma
12
Q
What non-infectious inflammatory masses are associated with calcium?
A
- Calcinosis cutis
- calcinosis circumscripta
13
Q
What non-infectious inflammatory masses are associated with extravasated blood?
A
- Haematoma
- Seroma
14
Q
What non-infectious inflammatory mass is associated with amyloid?
A
- Nodular cutaneous amyloidosis
15
Q
What non-infectious inflammatory masses are idiopathic?
A
- Canine juvenile granulomatous dermatitis (‘puppy strangles’)
- Sterile nodular granuloma and pyogranuloma
- Nodular dermatofibrosis in GSDs (linked with renal carcinoma)
- Canine cutaneous histiocytosis
16
Q
Urticaria, angiogenic oedema (angioedema) - causes
A
Degranulation of mast cells or basophils -> oedema (painless, pits on pressure)
Immunological:
§ Type I or III hypersensitivities
§ Mast cell tumours (rare)
Non-immunological (rare)
§ Physical forces (pressure, sunlight, heat, exercise)
§ Genetic abnormalities
§ Drugs/chemicals (incl food)
§ Venemous insects
§ Plants
17
Q
How common/rare are urticaria and angioedema in cats & dogs?
A
§ Dogs - uncommon
§ Cats – rare (insect sting often -> regional oedema of forelimb)
18
Q
Urticaria - CS
A
- Localised/generalised wheals, +/- pruritic
- Hair tufts over areas of swelling (d/d folliculitis in dog)
19
Q
Angioedema CS
A
§ Localised/generalised large oedematous swelling, usually involving head
§ +/- pruritus, exudation
§ Potentially fatal if involves airways
§ Associated with anaphylactic shock on rare occasions lesions on pinnae
20
Q
Urticaria and angioedema tx
A
- Many cases of urticaria resolve spontaneously in 12-48h, but owners should be instructed how to monitor for anaphylaxis
- If lesions acute and severe, monitor in-clinic
Treatment
* Dexamethasone iv
* Prednisolone (1mg/kg q24h 3-5 days and taper)
* May combine oral/injectable corticosteroids with oral
antihistamines (e.g. chlorpheniramine, diphenhydramine, hydroxyzine)
* Adrenaline if signs of anaphylaxis
* Avoid cause, if known
* Investigations into underlying cause if chronic
21
Q
What is calcinosis cutis?
A
= inappropriate deposition of calcium/phosphate in skin/subcutis
-> gritty white deposits, often with surrounding inflammation
22
Q
3 causes of calcinosis cutis
A
- Dystrophic calcification (deposition in injured, degenerating or dead tissue), e.g. in HAC
- Metastatic calcification (deposition associated with altered serum levels of calcium/phosphorus), e.g. chronic renal disease
- Idiopathic, e.g. Calcinosis circumscripta
23
Q
What is a haematoma?
A
= Loss of blood from damaged/ruptured blood vessel in/under skin
24
Q
Haematoma causes
A
§ Usually due to trauma
§ occasional clotting factor deficiencies/toxic causes – look for
other signs, history
25
Haematoma - cytology
- initially cytology is same as blood smear (though no platelets)
- macrophages (engulfing rbcs) +/- fibroblasts may appear with time
26
Haematoma management
§ Find cause and address if necessary
§ Usually self-limiting- keep quiet, ?apply pressure (light bandage), and wait to resorb
§ Occasionally acute, severe haemorrhage – identify source UGA and ligate if possible. Antibiotic cover – risk of secondary infection.
§ Occasionally drain
-- aural haematoma
27
What is a seroma?
= accumulation of sterile fluid (filtrate of blood) under a wound
§ Soft, non-painful swelling 2-5 days post-surgery (d/d infection). No heat on palpation.
28
Seroma FNA
- Straw-coloured/blood-tinged fluid
29
Seroma ddx
§ Haematoma
§ Abscess
30
Seroma management
§ Conservative unless refractory or causing wound disruption – may take several weeks
-- Pressure bandage for a week, if site allows?– use with care. Change every 48 hours
-- Keep quiet and confined
§ Repeated drainage?
-- Only if size causing discomfort. Tend to reform + risk of introducing infection
§ If severe: surgical debridement, flushing with isotonic solution, closure with careful apposition of tissues and insertion of Penrose drains. Biopsy and culture.
31
Arthropod bite granuloma cytology
- consistent with an inflammatory lesion
32
Arthropod bite granuloma - CS
- Small diameter
- Firm
- Ill-defined
- Erythematous
- Nodule
- Central black mark
33
Arthropod bite granuloma - management
§ Check no evidence of retained
arthropod (esp tick) mouthparts
§ May resolve without treatment
§ ?short course topical corticosteroid
§ If not resolving, consider surgical removal and submission for
histopathology and tissue culture to confirm diagnosis (NB need to be off corticosteroids, ideally for 2 weeks minimum, before sampling for histology)
34
What is panniculitis?
= inflammation of s/c fat
35
Panniculitis presentation
- Presents as nodules (single/multiple) +/- draining sinuses
- Easily confused with bacterial abscess
- Can be sterile or of infectious origin
36
Panniculitis diagnosis
§ FNA – pyogranulomatous inflammation with background fat
37
Panniculitis biopsy
§ Take samples for histopathology and bacterial and fungal tissue culture - important to rule out infection as initial step.
38
Panniculitis management if sterile
Consider possible underlying causes and correct where possible
* trauma/post-injection - likely to resolve with time
* nutritional - correct nutrient deficiency
* foreign material – excise if solitary lesion
* systemic disease (possible links with, e.g., pancreatitis)
* Others -?drug reactions, ?undetected infectious agent,?internal malignancy
If cannot identify/correct cause:
* Solitary lesion -> surgical excision if possible
* Multifocal lesion -> immunosuppressive therapy
39
Cutaneous neoplasia history & signalment
Age:
§ Neoplasia usually in older animals (except canine cutaneous histiocytoma)
Breed:
§ Some breed predispositions (e.g. Boxers and Golden Retrievers MCT)
Sex:
§ Hepatoid (perianal) adenomas more common in male dogs
Duration/progression:
§ may indicate if benign (slower-growing) or malignant
Paraneoplastic signs?:
§ e.g. MCT may show fluctuant size/ inflammation/ pruritus/ vomiting
MCT
40
Is the skin the most common site for neoplasia in dogs/cats?
- yes (25-58% of all neoplasms)
41
Origins of neoplasia
§ Any cell type can become neoplastic
§ Epithelium -> epithelial cell neoplasms
§ Mesenchyme -> mesenchymal (spindle) cell neoplasms
§ Round cells -> round cell neoplasms
§ Others (uncommon)
-- Melanocytes
-- Metastasis from non-cutaneous neoplasm
42
Are most canine skin tumours benign or malignant?
§ Most benign (approx 2/3)
§ Cured with wide local excision
§ Histiocytoma and papilloma may regress spontaneously
43
Malignant canine skin tumours
§ Mast cell tumour (11% total)
§ Squamous cell carcinoma (SCC) (1%)
§ Malignant melanoma (3%)
§ Soft tissue sarcomas (4%)
§ Epitheliotropic lymphoma
44
Most common canine skin tumours
§ Lipoma – most common
§ Sebaceous gland tumours (6-21%)
§ Mast cell tumour (11%)
§ Histiocytoma (10%)
§ Basal cell tumour (4-11%)
45
Are most feline skin tumours benign or malignant?
§ Most malignant (approx 2/3)
46
Most common feline skin tumours
§ Fibrosarcomas (25%)
§ Squamous cell carcinomas (SCC) (17%)
§ Basal cell tumours (15%)
§ Mast cell tumours (7%)
47
Are most skin neoplasias painful or painless? Fast or slow growing?
- Most are painless and slow-growing
48
Which neoplasms present as multiple nodules?
§ epitheliotropic/primary cutaneous lymphomas
§ papillomas
§ malignant tumours that metastasise to skin
§ basal cell carcinoma in cats
49
Are epithelial tumours usually superficial or deeper?
– usually superficial and
exophytic (ie grow out from epithelial surface)
50
Are mesenchymal/round cell/adnexal tumours superficial or deeper?
– usually intradermal or s/c, and endophytic (i.e. grow inwards)
51
Epithelial cell tumour FNA cytology
§ High yield, cells associated with one another, rafts, sheets, acini, cuboidal, columnar
52
Spindle/mesenchymal cell tumour FNA cytology
§ Low yield, spindle shaped cells, usually single but may be in association/sheets, may be “matrix”
53
Round cell tumour FNA cytology
§ High yield, discrete round cells, not adherent
54
Epithelial cell tumour examples
Epidermal cells:
* Squamous papilloma
* Squamous cell carcinoma (SCC)
* Multicentric squamous cell carcinoma insitu (Bowen’s disease)
* Basal cell tumour (carcinoma rare)
* Keratoacanthoma
Follicular hair matrix/follicular epithelial components:
* Trichoepithelioma, pilomatrixoma
Glandular (sebaceous, epitrichial, ceruminous, hepatoid/perianal):
* adenoma/ adenocarcinoma
55
Characteristics of epithelial cell tumours
* Many types
* Most benign
* Most slow-growing
* Most cured by wide surgical excision
56
Mesenchymal/spindle cell tumour examples
Spindle cell sarcoma
* Perivascular wall tumours – dog
* Peripheral nerve sheath tumours
* Fibrosarcoma
* Myxosarcoma
Blood/lymphatic vessels
* Haemangioma/ haemangiosarcoma
* Lymphangioma/ lymphangiosarcoma
Adipose tissue
* Lipoma/ liposarcoma
* Fibrolipoma, infiltrative lipoma
Fibrous tissue
* Fibroma
57
Mesenchymal/spindle cell characteristics
* Most do not exfoliate well on FNA (except lipoma) – need incisional biopsy to diagnose
* Spindle cell sarcomas - low rates of metastasis but locally invasive. Wide and deep surgical excision where possible; or cytoreductive surgery + radiotherapy
58
Round cell tumour examples
* Mast cell tumour
* Plasmacytoma
* Lymphoma
-- Primary cutaneous
lymphoma (T or B-
cell)
-- Epitheliotropic (T-cell)
* Histiocytic tumours
-- Canine cutaneous histiocytomas
-- Reactive histiocytosis
-- Histiocytic sarcoma
complex
* Canine transmissible
venereal tumours
59
Melanocytic cell tumour examples
* Melanoma
-- Benign dermal
-- Malignant
60
Use of skin biopsy and histopathology
§ to confirm putative diagnosis from FNA
§ where FNA is inconclusive
61
Elliptical incisional skin biopsy
§ Include margin
§ Take from representative area
§ Ensure to remove whole biopsy tract when mass removed
62
Elliptical excisional skin biopsy
§ May cure benign, non-infiltrative neoplasms
§ Remove deeper tissue en bloc so can assess all margins (send untrimmed), but can never confirm 100% excision
§ Not if suspect infiltrative mass – look at FNA cytology first
63
MCT - excision
Needs wide excision:
§ with minimum 2cm margins
§ down to and including muscle or fascial plane below tumour
64
Biopsy/remove draining lymph node (LN) for neoplasia
- Should do FNA for all enlarged LNs
- If firm node negative for neoplasia on FNA, take excisional biopsy under GA for histopathology
65
Immunohistochemistry for neoplasia
- Needed in occasional cases
- Labels cell-surface markers -> help identify phenotype of cells in neoplasm, esp for some round cell tumours, e.g. lymphoma, MCT NB
* Highly anaplastic cells may still remain unidentifiable
* Discuss value and sampling requirements with histopathologist
before taking sample
66
PARR testing for neoplasia
= PCR for antigen-receptor rearrangement
- To distinguish neoplastic from inflammatory populations, e.g. in lymphoma
67
Tx options for neoplasia
- Surgery – most common modality
- Chemotherapy
- Radiotherapy
68
Principles of skin tumour excision
Choice of margin is paramount: wider margins needed for more infiltrative tumours
69
What are the natural barrier to tumour spread?
- collagen-rich, relatively avascular structures (eg fascia, tendons, ligaments, cartilage)
70
Different surgical margins for neoplasia
* Cytoreductive excision
* Marginal local excision
-- ?for non-infiltrating lipomas, histiocytomas, benign sebaceous tumours
* Wide excision – most-commonly employed for skin tumours
-- = removal with complete margins of normal tissue in all
directions
* Radical (compartmental) excision
71
1cm (wide local) margin for surgical excision (what tumours? what depth?)
Tumour
- Grade I (low grade) MCT
- Grade I soft tissue sarcoma (spindle cell sarcoma)
- Well-differentiated SCC
Depth
Down to and including muscle or fascial plane below tumour
72
2cm (wide local) margin for surgical excision (what tumours? what depth?)
Tumour
- Grade II (intermediate grade) MCT
- Intermediate/poorly-differentiated SCC
Depth
- Down to and including muscle or fascial plane below tumour
73
3cm margin for surgical excision (what tumours? what depth?)
Tumour
- Grade III (high grade) MCTs
- Grade II and III soft tissue sarcomas (spindle cell sarcoma)
- Feline vaccine-associated sarcomas
Depth
- Down to and including uninvolved muscle or fascial plane below tumour
74
3 golden rules to the approach to cancer cases
1. Establish the diagnosis (type and grade of tumour)
2. Establish the extent/stage of the disease
3. Investigate any complications
75
When to refer neoplasias?
If advanced skin reconstruction required
§ Best to refer in the first instance, cf after conservative surgery
For radiotherapy
§ Best to contact oncologist before surgery – may advise preferred surgery to optimise efficacy of radiotherapy
For chemotherapy
§ if unsure re use of chemotherapeutic drugs, including control of side effects and protection of people
Also consult oncologist for advice re best approach in an individual case
76
Sebaceous gland tumours - why type of tumour? solitary or multiple?
- epithelial
- solitary or multiple
77
Sebaceous gland tumours - prevalence
§ Common in dogs - 6-21% skin tumours – almost all benign
-- Sebaceous hyperplasia (50%) – ‘warty’
-- Sebaceous adenoma (8%) – dome-shaped /papillated
-- Sebaceous epithelioma (40%) - firm nodular plaque/ fungiform mass
§ 1-2% sebaceous adenocarcinoma
78
Sebaceous gland tumours - what are they often referred to as?
§ Often referred to (erroneously) as ‘warts’
79
Sebaceous gland tumours - tx
§ If slow-growing and well-circumscribed, may leave and monitor
§ Excise if any change or traumatised
80
Basal cell tumour - prevalence
- Cat: common (15-35% skin tumours)
-- The most common pigmented tumour in cats (d/d melanoma)
- Dog: 5-10% skin tumours
81
Basal cell tumour - why type of tumour?
- epithelial
82
Basal cell tumour in cats - characteristics & tx
§ Aggressive characteristics on cytology/histopathology but low-grade behaviour usually
§ Excise with as wide a margin as possible
83
Basal cell tumour in dogs - characteristics & tx
§ Usually benign, slow-growing.
§ Wide excision to cure
84
Canine papillomas (warts) - characteristics/presentation
Young dogs, multiple lesions
§ Mouth, lips, eyes – smooth, shiny plaques or papillated lesions
§ Footpads - firm, hyperkeratotic, often hornlike lesions
85
Canine papillomas (warts) - why type of tumour?
- epithelial
86
Canine papillomas (warts) - cause & spread
- Caused by papilloma viruses
- contagious via direct/indirect contact
87
Canine papillomas (warts) - management
§ Usually allow to resolve spontaneously, though new ones may develop
§ Surgery if causing problems
§ Topical keratolytic/softening preparations? Decreases discomfort but
does not alter the course of the infection
§ Imiquimod cream? Interferon? Azithromycin? Anecdotal reports
88
Pigmented viral plaques - breed? what can happen to them?
* Especially French bulldogs, pugs
* May not spontaneously resolve and occasionally -> SCC
* Care re concurrent use of immunosuppressive drugs
89
Pigmented viral plaques - why type of tumour?
- epithelial
90
Perianal (hepatoid) gland tumour in dogs - benign or malignant?
§ Adenomas/hyperplasia usually (benign); occasionally malignant
91
Perianal (hepatiod) gland tumour in dogs - why type of tumour?
- epithelial
92
Perianal (hepatoid) gland tumour in dogs - cause?
§ Usually androgen-dependent
93
Perianal (hepatoid) gland tumour in dogs - signalment
§ Usually older male, but <25% in females
§ In entire and neutered animals
94
Perianal (hepatoid) gland tumour in dogs - presentation/CS
§ Usually in perianal skin (occasionally tail base, dorsal lumbosacral, lateral to prepuce)
§ Nodules or perianal ’ring’ of lesions, +/- ulceration
95
Perianal (hepatoid) gland tumour in dogs - tx
§ Hormonal – surgical or chemical castration – most will regress
§ If necessary, wide surgical excision (+/- prior hormonal therapy);
surgery + radiotherapy if necessary
(In NM and females, consider if underlying HAC -> androgen production by hyperplastic adrenals)
96
Lipoma - why type of tumour?
- mesenchymal
97
Lipoma - signalment
- Common in dog, especially if female, obese
98
Lipoma - presentation
- usually on trunk
- dermal or sc
99
Lipoma - 2 forms
§ Non-infiltrating – usual form - encapsulated, soft, moveable
§ Infiltrating variant – uncommon
Both benign
100
Lipoma - management
§ Can leave if monitor intermittently if positively identified, slow-growing and causing no problem – NB can become very large
-- Always check with FNA. Do not use fixative (1st DiffQuick stain)
-- See fat and often few cells (adipocytes)
* d/d mast cell tumour, perivascular tumour
* ensure to sample mass, not surrounding normal adipose tissue
§ If to excise: wide surgical excision – curative for encapsulated form, infiltrative form likely to recur
101
Spindle cell sarcomas - why type of tumour?
- mesenchymal
102
Spindle cell sarcomas - prevalence
§ Relatively common in dog and cat
103
Spindle cell sarcomas - presentation
§ Lesions in dermis, s/c or deep fascia
§ Tissue of origin varies but most behave similarly
-- Solitary, slow-growing masses
-- May appear well-circumscribed but actually highly infiltrative
-- Low rate of metastasis
104
Spindle cell sarcomas - diagnosis
§ Diagnosis on biopsy
– NB poor exfoliation on FNA (except perivascular wall tumours)
105
Spindle cell sarcomas - tx
§ Wide-radical excision, if possible, but frequently recur as incompletely excised
§ Or cytoreductive surgery + radiotherapy
§ Chemotherapy of little value
106
Feline fibrosarcoma - why type of tumour?
- mesenchymal
107
Feline fibrosarcoma - behaviour (& the exception to this)
- Generally, behave as canine soft tissue sarcomas and treated similarly
- NB do not ‘shell out’ mass in pseudocapsule - ‘the first surgery is the best surgery’
Except
- ‘Injection site sarcomas’
§ Association between fibrosarcomas and injection sites recognised in cats
§ Usually interscapular
§ If suspect, inform pharmaceutical company as suspect adverse reaction
§ Consult oncologist after biopsy but before surgery
108
MCT - why type of tumour?
- round cell
109
Canine MCT - appearance
§ Can be cutaneous (dermal) or s/c. Occasionally extracutaneous
§ 50% on trunk, 25-40% on extremities, 10% on neck
§ Always a d/d for any cutaneous tumour!
§ Low grade – solitary slow-growing dermal nodules – often overlooked
§ Higher grade –may be large ill-defined soft masses (d/d lipoma, soft tissue sarcoma), +/- satellite lesions
§ +/- ulceration
§ Mast cell degranulation à histamine release
-> erythema, pruritus, oedema
-> may fluctuate in size
So d/d inflammatory masses, e.g. cellulitis, acral lick granulomas
110
Canine MCT - paraneoplastic syndromes
– from mast cell degranulation – granules contain:
§ Histamine
-> Local effects - +/- oedema, erythema of tumour/adjacent tissue, pruritus*
-> Systemic effects – +/- GI ulceration & melaena, vomiting, occasional
oedema/anaphylaxis/collapse (handle suspect MCT carefully!)
§ Heparin -> local bruising and perioperative bleeding
§ Proteases -> poor wound healing
* Darier’s sign = local pruritus, erythema, wheal after rubbing lesion
111
Diagnosis of MCT
- FNA of mass – cytology -> MCT
- Incisional/excisional biopsy to grade – NB take adequate margins
-- Grade I, II, III – Patnaik system and/or low/high grade (Kiupel system)
-- +/- other indices
* e.g. Ki67, mitotic index, AgNORs
* especially useful for predicting behaviour of Grade II tumours
- Stage – regional LNs +/- imaging/FNA of liver/spleen (most likely sites of metastasis)
112
Grading & prognosis of MCT
Well differentiated
-Grade I
- Low-grade/benign
- <10% metastasise
- Good prognosis
Intermediate differentiation
- Grade II
- Intermediate
- 5-20% metastasise
- Intermediate prognosis
Poorly differentiated
- Grade III
- High-grade/invasive
- >75% metastasise
- Poor prognosis
113
MCT tx
Surgery – treatment of choice where possible
Chemotherapy
* Various protocols involving vinblastine, prednisolone, lomustine (CCNU), cyclophosphamide, chlorambucil
* Tyrosine kinase inhibitors – mastinib, toceranib phosphate – if inoperable
* Protein kinase C activator – tigilanol tiglate (Stelfonta®) – new drug for intralesional injection of
selected non-resectable, non-metastatic MCTs -> necrosis of mass
Radiotherapy
114
What grade are the majority of MCT?
- Grade II
115
Tx of well/intermediately-differentiated MCT (grade I/II) with no evidence of metastasis
- surgical excision
116
Tx of well/intermediately differentiated MCT (Grade I/II), no evidence of metastasis on distal extremities
If surgery feasible:
- debulking surgery ± radiotherapy
If surgery not feasible:
- ± debulking surgery
- cytoreduction
- radiotherapy
117
Tx of metastatic dz of MCT or poorly differentiated MCT (grade III)
- surgery if small and no metastasis - risk and not recommended
- radiotherapy?
- chemotherapy?
118
Feline MCT - presentation
§ Most commonly on skin
§ Lesions usually solitary, well circumscribed nodules/plaques, alopecic
§ Occasional visceral lesions (spleen, intestine) -> vomiting, anorexia
119
Feline MCT - diagnosis
§ Cytology -> mast cells
§ Histopathology -> divide to
-- Well-differentiated mastocytic – 60%
-- Pleomorphic mastocytic – 30%
-- Atypical (histiocytic) – 10% – classically young cats <4yo – masses regress in time
Also graded to Group 1 (benign), Group 2 (malignant)
120
Feline MCT - tx
§ Surgery – treatment of choice for solitary masses
§ Chemotherapy? – questionable justification unless tumour aggressive, as cats rarely die of MCTs
121
Primary cutaneous lymphoma - why type of tumour?
- round cell
122
Primary cutaneous lymphoma - 2 clinical presentations
1. Epitheliotropic lymphoma (mycosis fungoides)
(usually T-cell origin)
2. Non-epitheliotropic lymphoma Less common than 1. (T- or B-cell origin)
123
Epitheliotropic lymphoma - manifestations
§ Foci of erythroderma, crusting, ulceration
§ Multiple dermal nodules/erythematous plaques
§ Generalised form: scale, pruritus, erythema, crust
§ Mucocutaneous lesions (may depigment)
-- Often the first sign of epitheliotropic lymphoma, before progressing to other forms
124
Non-epitheliotropic lymphoma - manifestations
§ Foci of erythroderma, crusting, ulceration
§ Multiple dermal nodules/erythematous plaques
125
Primary cutaneous lymphoma - diagnosis
§ FNA cytology -> round cell/lymphoid tumour
§ Histopathology
§ IHC? Not for epitheliotropic lymphoma as usually T-cell origin
§ PARR testing for clonality? Useful if concurrent inflammation and little cellular atypia
126
Primary cutaneous lymphoma - prognosis/management
Non-epitheliotropic lymphoma
- Rapid metastasis, grave prognosis
Epitheliotropic lymphoma
- Chronic, may wax/wane initially
127
Primary cutaneous lymphoma - tx
median survival time in terms of months
§ Chemotherapy?
§ CCNU (Lomustine) + prednisolone
§ Retinoids?
§ Surgery if solitary/localised?
§ Surgery or radiotherapy if localised EL of lips/mouth?
128
Canine cutaneous histiocytoma - why type of tumour?
- round cell
129
Canine cutaneous histiocytoma - prevalence, presentation
§ Common (10% skin tumours) rapidly-growing well- demarcated masses. May ulcerate
§ Frequently young dogs. Commonly on extremities
§ Increased frequency in dogs on immunosuppressive
treatments
130
Canine cutaneous histiocytoma - FNA
§ Histiocytes (round cells) on FNA – d/d MCT
131
Canine cutaneous histiocytoma - management
§ Frequently resolve spontaneously – do not use immunosuppressive drugs as may slow regression
132
Melanoma - presentation
Usually
§ well-defined deeply-pigmented flat/plaque/dome-shaped lesions in pigmented skin
§ >85% benign -> wide excision
(Malignant tumours often less well-pigmented +/- ulcerated)
But
§ mucocutanous (e.g. eyelid, lip, oral) melanomas
§ digital melanomas potentially malignant with widespread metastasis
133
Melanoma - tx
- Excise with wide margins where possible
- Not chemosensitive
- New immunotherapy treatment in USA
§ Xenogeneic plasmid DNA vaccine (Oncept®) targeting tyrosinase
§ licensed for oral/mucosal melanoma
134
Cutaneous cysts - definition
§ epithelium-lined cavity containing fluid or solid material
135
Cutaneous cysts - forms
In skin, usually lined with adnexal epithelium: eg
§ Follicular cysts -> cornified debris
§ Apocrine cysts -> apocrine secretions
§ Sebaceous cysts -> sebaceous secretions
136
Cutaneous cysts - presentation
§ Well-circumscribed; usually solitary, sometimes multiple
§ Some with central pore
137
Cutaneous cysts - management
§ May observe without treatment but risk of rupture (especially at certain sites) so may elect to excise
§ If rupture -> inflammation +/- infection
§ Resolve inflammation/infection before excision
138
Dermoid cyst - presentation
- Congenital defect, esp Rhodesian Ridgeback
- Cysts dorsal midline neck/trunk
- Filled with hair/keratinous material
- May extend to dura mater
-- causingneurological problems
-- excision potentially complex
139
What is emphysema?
- air under the skin
140
Urticaria vs angioedema
- urticaria = hives
- angioedema = whole body swells up
