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Y4 SA dermatology > Cutaneous masses > Flashcards

Cutaneous masses Flashcards

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Dermatology Board Prep flashcards
1
Q

Swellings of non-dermatologic origins

A

▪ Hernias
▪ Oedema
▪ Bursitis
▪ Emphysema
▪ Mammary tumours

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2
Q

Types of skin masses

A
  • Inflammatory (infectious & non-infectious)
  • Neoplastic
  • Hyperplastic/dysplastic
  • Cyst
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3
Q

Examples of infectious (septic) skin masses

A
  • Bacterial infection
  • Fungal infection
  • Protozoal infection
  • Demodex
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4
Q

Examples of non-infectious (sterile) skin masses

A
  • Urticaria/angioedema
  • Eosinophilic granuloma
  • Arthropod bite granuloma
  • Sterile panniculitis
  • Haematoma Seroma
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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

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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

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7
Q

FNA cytology of an neoplastic mass - what do you see?

A

▪ Round cell vs epithelial vs spindle cell

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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

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9
Q

What non-infectious inflammatory masses are associated with mast cell degranulation?

A
  • Urticaria
  • Angiogenic oedema
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10
Q

What non-infectious inflammatory masses are associated with degenerated collagen?

A
  • Eosinophilic granuloma (especially cat)
  • Arthropod bite granuloma
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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
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12
Q

What non-infectious inflammatory masses are associated with calcium?

A
  • Calcinosis cutis
  • calcinosis circumscripta
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13
Q

What non-infectious inflammatory masses are associated with extravasated blood?

A
  • Haematoma
  • Seroma
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14
Q

What non-infectious inflammatory mass is associated with amyloid?

A
  • Nodular cutaneous amyloidosis
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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
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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

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17
Q

How common/rare are urticaria and angioedema in cats & dogs?

A

§ Dogs - uncommon
§ Cats – rare (insect sting often -> regional oedema of forelimb)

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18
Q

Urticaria - CS

A
  • Localised/generalised wheals, +/- pruritic
  • Hair tufts over areas of swelling (d/d folliculitis in dog)
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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

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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

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21
Q

What is calcinosis cutis?

A

= inappropriate deposition of calcium/phosphate in skin/subcutis
-> gritty white deposits, often with surrounding inflammation

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22
Q

3 causes of calcinosis cutis

A
  1. Dystrophic calcification (deposition in injured, degenerating or dead tissue), e.g. in HAC
  2. Metastatic calcification (deposition associated with altered serum levels of calcium/phosphorus), e.g. chronic renal disease
  3. Idiopathic, e.g. Calcinosis circumscripta
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23
Q

What is a haematoma?

A

= Loss of blood from damaged/ruptured blood vessel in/under skin

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24
Q

Haematoma causes

A

§ Usually due to trauma
§ occasional clotting factor deficiencies/toxic causes – look for
other signs, history

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25
Q

Haematoma - cytology

A
  • initially cytology is same as blood smear (though no platelets)
  • macrophages (engulfing rbcs) +/- fibroblasts may appear with time
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26
Q

Haematoma management

A

§ 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

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27
Q

What is a seroma?

A

= 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.

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28
Q

Seroma FNA

A
  • Straw-coloured/blood-tinged fluid
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29
Q

Seroma ddx

A

§ Haematoma
§ Abscess

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30
Q

Seroma management

A

§ 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.

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31
Q

Arthropod bite granuloma cytology

A
  • consistent with an inflammatory lesion
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32
Q

Arthropod bite granuloma - CS

A
  • Small diameter
  • Firm
  • Ill-defined
  • Erythematous
  • Nodule
  • Central black mark
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33
Q

Arthropod bite granuloma - management

A

§ 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)

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34
Q

What is panniculitis?

A

= inflammation of s/c fat

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35
Q

Panniculitis presentation

A
  • Presents as nodules (single/multiple) +/- draining sinuses
  • Easily confused with bacterial abscess
  • Can be sterile or of infectious origin
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36
Q

Panniculitis diagnosis

A

§ FNA – pyogranulomatous inflammation with background fat

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37
Q

Panniculitis biopsy

A

§ Take samples for histopathology and bacterial and fungal tissue culture - important to rule out infection as initial step.

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38
Q

Panniculitis management if sterile

A

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

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39
Q

Cutaneous neoplasia history & signalment

A

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

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40
Q

Is the skin the most common site for neoplasia in dogs/cats?

A
  • yes (25-58% of all neoplasms)
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41
Q

Origins of neoplasia

A

§ 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

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42
Q

Are most canine skin tumours benign or malignant?

A

§ Most benign (approx 2/3)
§ Cured with wide local excision
§ Histiocytoma and papilloma may regress spontaneously

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43
Q

Malignant canine skin tumours

A

§ Mast cell tumour (11% total)
§ Squamous cell carcinoma (SCC) (1%)
§ Malignant melanoma (3%)
§ Soft tissue sarcomas (4%)
§ Epitheliotropic lymphoma

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44
Q

Most common canine skin tumours

A

§ Lipoma – most common
§ Sebaceous gland tumours (6-21%)
§ Mast cell tumour (11%)
§ Histiocytoma (10%)
§ Basal cell tumour (4-11%)

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45
Q

Are most feline skin tumours benign or malignant?

A

§ Most malignant (approx 2/3)

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46
Q

Most common feline skin tumours

A

§ Fibrosarcomas (25%)
§ Squamous cell carcinomas (SCC) (17%)
§ Basal cell tumours (15%)
§ Mast cell tumours (7%)

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47
Q

Are most skin neoplasias painful or painless? Fast or slow growing?

A
  • Most are painless and slow-growing
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48
Q

Which neoplasms present as multiple nodules?

A

§ epitheliotropic/primary cutaneous lymphomas
§ papillomas
§ malignant tumours that metastasise to skin
§ basal cell carcinoma in cats

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49
Q

Are epithelial tumours usually superficial or deeper?

A

– usually superficial and
exophytic (ie grow out from epithelial surface)

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50
Q

Are mesenchymal/round cell/adnexal tumours superficial or deeper?

A

– usually intradermal or s/c, and endophytic (i.e. grow inwards)

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51
Q

Epithelial cell tumour FNA cytology

A

§ High yield, cells associated with one another, rafts, sheets, acini, cuboidal, columnar

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52
Q

Spindle/mesenchymal cell tumour FNA cytology

A

§ Low yield, spindle shaped cells, usually single but may be in association/sheets, may be “matrix”

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53
Q

Round cell tumour FNA cytology

A

§ High yield, discrete round cells, not adherent

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54
Q

Epithelial cell tumour examples

A

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

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55
Q

Characteristics of epithelial cell tumours

A
  • Many types
  • Most benign
  • Most slow-growing
  • Most cured by wide surgical excision
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56
Q

Mesenchymal/spindle cell tumour examples

A

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

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57
Q

Mesenchymal/spindle cell characteristics

A
  • 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
Q

Round cell tumour examples

A
  • 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
Q

Melanocytic cell tumour examples

A
  • Melanoma
    – Benign dermal
    – Malignant
60
Q

Use of skin biopsy and histopathology

A

§ to confirm putative diagnosis from FNA
§ where FNA is inconclusive

61
Q

Elliptical incisional skin biopsy

A

§ Include margin
§ Take from representative area
§ Ensure to remove whole biopsy tract when mass removed

62
Q

Elliptical excisional skin biopsy

A

§ 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
Q

MCT - excision

A

Needs wide excision:
§ with minimum 2cm margins
§ down to and including muscle or fascial plane below tumour

64
Q

Biopsy/remove draining lymph node (LN) for neoplasia

A
  • Should do FNA for all enlarged LNs
  • If firm node negative for neoplasia on FNA, take excisional biopsy under GA for histopathology
65
Q

Immunohistochemistry for neoplasia

A
  • 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
Q

PARR testing for neoplasia

A

= PCR for antigen-receptor rearrangement
- To distinguish neoplastic from inflammatory populations, e.g. in lymphoma

67
Q

Tx options for neoplasia

A
  • Surgery – most common modality
  • Chemotherapy
  • Radiotherapy
68
Q

Principles of skin tumour excision

A

Choice of margin is paramount: wider margins needed for more infiltrative tumours

69
Q

What are the natural barrier to tumour spread?

A
  • collagen-rich, relatively avascular structures (eg fascia, tendons, ligaments, cartilage)
70
Q

Different surgical margins for neoplasia

A
  • 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
Q

1cm (wide local) margin for surgical excision (what tumours? what depth?)

A

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
Q

2cm (wide local) margin for surgical excision (what tumours? what depth?)

A

Tumour
- Grade II (intermediate grade) MCT
- Intermediate/poorly-differentiated SCC

Depth
- Down to and including muscle or fascial plane below tumour

73
Q

3cm margin for surgical excision (what tumours? what depth?)

A

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
Q

3 golden rules to the approach to cancer cases

A
  1. Establish the diagnosis (type and grade of tumour)
  2. Establish the extent/stage of the disease
  3. Investigate any complications
75
Q

When to refer neoplasias?

A

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
Q

Sebaceous gland tumours - why type of tumour? solitary or multiple?

A
  • epithelial
  • solitary or multiple
77
Q

Sebaceous gland tumours - prevalence

A

§ 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
Q

Sebaceous gland tumours - what are they often referred to as?

A

§ Often referred to (erroneously) as ‘warts’

79
Q

Sebaceous gland tumours - tx

A

§ If slow-growing and well-circumscribed, may leave and monitor
§ Excise if any change or traumatised

80
Q

Basal cell tumour - prevalence

A
  • Cat: common (15-35% skin tumours)
    – The most common pigmented tumour in cats (d/d melanoma)
  • Dog: 5-10% skin tumours
81
Q

Basal cell tumour - why type of tumour?

A
  • epithelial
82
Q

Basal cell tumour in cats - characteristics & tx

A

§ Aggressive characteristics on cytology/histopathology but low-grade behaviour usually
§ Excise with as wide a margin as possible

83
Q

Basal cell tumour in dogs - characteristics & tx

A

§ Usually benign, slow-growing.
§ Wide excision to cure

84
Q

Canine papillomas (warts) - characteristics/presentation

A

Young dogs, multiple lesions
§ Mouth, lips, eyes – smooth, shiny plaques or papillated lesions
§ Footpads - firm, hyperkeratotic, often hornlike lesions

85
Q

Canine papillomas (warts) - why type of tumour?

A
  • epithelial
86
Q

Canine papillomas (warts) - cause & spread

A
  • Caused by papilloma viruses
  • contagious via direct/indirect contact
87
Q

Canine papillomas (warts) - management

A

§ 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
Q

Pigmented viral plaques - breed? what can happen to them?

A
  • Especially French bulldogs, pugs
  • May not spontaneously resolve and occasionally -> SCC
  • Care re concurrent use of immunosuppressive drugs
89
Q

Pigmented viral plaques - why type of tumour?

A
  • epithelial
90
Q

Perianal (hepatoid) gland tumour in dogs - benign or malignant?

A

§ Adenomas/hyperplasia usually (benign); occasionally malignant

91
Q

Perianal (hepatiod) gland tumour in dogs - why type of tumour?

A
  • epithelial
92
Q

Perianal (hepatoid) gland tumour in dogs - cause?

A

§ Usually androgen-dependent

93
Q

Perianal (hepatoid) gland tumour in dogs - signalment

A

§ Usually older male, but <25% in females
§ In entire and neutered animals

94
Q

Perianal (hepatoid) gland tumour in dogs - presentation/CS

A

§ Usually in perianal skin (occasionally tail base, dorsal lumbosacral, lateral to prepuce)
§ Nodules or perianal ’ring’ of lesions, +/- ulceration

95
Q

Perianal (hepatoid) gland tumour in dogs - tx

A

§ 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
Q

Lipoma - why type of tumour?

A
  • mesenchymal
97
Q

Lipoma - signalment

A
  • Common in dog, especially if female, obese
98
Q

Lipoma - presentation

A
  • usually on trunk
  • dermal or sc
99
Q

Lipoma - 2 forms

A

§ Non-infiltrating – usual form - encapsulated, soft, moveable
§ Infiltrating variant – uncommon

Both benign

100
Q

Lipoma - management

A

§ 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
Q

Spindle cell sarcomas - why type of tumour?

A
  • mesenchymal
102
Q

Spindle cell sarcomas - prevalence

A

§ Relatively common in dog and cat

103
Q

Spindle cell sarcomas - presentation

A

§ 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
Q

Spindle cell sarcomas - diagnosis

A

§ Diagnosis on biopsy
– NB poor exfoliation on FNA (except perivascular wall tumours)

105
Q

Spindle cell sarcomas - tx

A

§ Wide-radical excision, if possible, but frequently recur as incompletely excised
§ Or cytoreductive surgery + radiotherapy
§ Chemotherapy of little value

106
Q

Feline fibrosarcoma - why type of tumour?

A
  • mesenchymal
107
Q

Feline fibrosarcoma - behaviour (& the exception to this)

A
  • 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
Q

MCT - why type of tumour?

A
  • round cell
109
Q

Canine MCT - appearance

A

§ 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
Q

Canine MCT - paraneoplastic syndromes

A

– 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
Q

Diagnosis of MCT

A
  • 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
Q

Grading & prognosis of MCT

A

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
Q

MCT tx

A

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
Q

What grade are the majority of MCT?

A
  • Grade II
115
Q

Tx of well/intermediately-differentiated MCT (grade I/II) with no evidence of metastasis

A
  • surgical excision
116
Q

Tx of well/intermediately differentiated MCT (Grade I/II), no evidence of metastasis on distal extremities

A

If surgery feasible:
- debulking surgery ± radiotherapy

If surgery not feasible:
- ± debulking surgery
- cytoreduction
- radiotherapy

117
Q

Tx of metastatic dz of MCT or poorly differentiated MCT (grade III)

A
  • surgery if small and no metastasis - risk and not recommended
  • radiotherapy?
  • chemotherapy?
118
Q

Feline MCT - presentation

A

§ Most commonly on skin
§ Lesions usually solitary, well circumscribed nodules/plaques, alopecic
§ Occasional visceral lesions (spleen, intestine) -> vomiting, anorexia

119
Q

Feline MCT - diagnosis

A

§ 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
Q

Feline MCT - tx

A

§ Surgery – treatment of choice for solitary masses
§ Chemotherapy? – questionable justification unless tumour aggressive, as cats rarely die of MCTs

121
Q

Primary cutaneous lymphoma - why type of tumour?

A
  • round cell
122
Q

Primary cutaneous lymphoma - 2 clinical presentations

A
  1. Epitheliotropic lymphoma (mycosis fungoides)
    (usually T-cell origin)
  2. Non-epitheliotropic lymphoma Less common than 1. (T- or B-cell origin)
123
Q

Epitheliotropic lymphoma - manifestations

A

§ 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
Q

Non-epitheliotropic lymphoma - manifestations

A

§ Foci of erythroderma, crusting, ulceration
§ Multiple dermal nodules/erythematous plaques

125
Q

Primary cutaneous lymphoma - diagnosis

A

§ 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
Q

Primary cutaneous lymphoma - prognosis/management

A

Non-epitheliotropic lymphoma
- Rapid metastasis, grave prognosis

Epitheliotropic lymphoma
- Chronic, may wax/wane initially

127
Q

Primary cutaneous lymphoma - tx

A

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
Q

Canine cutaneous histiocytoma - why type of tumour?

A
  • round cell
129
Q

Canine cutaneous histiocytoma - prevalence, presentation

A

§ 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
Q

Canine cutaneous histiocytoma - FNA

A

§ Histiocytes (round cells) on FNA – d/d MCT

131
Q

Canine cutaneous histiocytoma - management

A

§ Frequently resolve spontaneously – do not use immunosuppressive drugs as may slow regression

132
Q

Melanoma - presentation

A

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
Q

Melanoma - tx

A
  • 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
Q

Cutaneous cysts - definition

A

§ epithelium-lined cavity containing fluid or solid material

135
Q

Cutaneous cysts - forms

A

In skin, usually lined with adnexal epithelium: eg
§ Follicular cysts -> cornified debris
§ Apocrine cysts -> apocrine secretions
§ Sebaceous cysts -> sebaceous secretions

136
Q

Cutaneous cysts - presentation

A

§ Well-circumscribed; usually solitary, sometimes multiple
§ Some with central pore

137
Q

Cutaneous cysts - management

A

§ 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
Q

Dermoid cyst - presentation

A
  • 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
Q

What is emphysema?

A
  • air under the skin
140
Q

Urticaria vs angioedema

A
  • urticaria = hives
  • angioedema = whole body swells up

Y4 SA dermatology (22 decks)

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