Cutaneous masses Flashcards
Swellings of non-dermatologic origins
▪ Hernias
▪ Oedema
▪ Bursitis
▪ Emphysema
▪ Mammary tumours
Types of skin masses
- Inflammatory (infectious & non-infectious)
- Neoplastic
- Hyperplastic/dysplastic
- Cyst
Examples of infectious (septic) skin masses
- Bacterial infection
- Fungal infection
- Protozoal infection
- Demodex
Examples of non-infectious (sterile) skin masses
- Urticaria/angioedema
- Eosinophilic granuloma
- Arthropod bite granuloma
- Sterile panniculitis
- Haematoma Seroma
Investigating a skin mass
▪ 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
FNA cytology of an inflammatory mass - what do you see?
▪ 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
FNA cytology of an neoplastic mass - what do you see?
▪ Round cell vs epithelial vs spindle cell
FNA cytology of a cyst - what do you see?
▪ 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
What non-infectious inflammatory masses are associated with mast cell degranulation?
- Urticaria
- Angiogenic oedema
What non-infectious inflammatory masses are associated with degenerated collagen?
- Eosinophilic granuloma (especially cat)
- Arthropod bite granuloma
What non-infectious inflammatory masses are associated with fatty-acids / lipids
- Sterile panniculitis, various causes:
– Traumatic
– post-injection (‘injection reaction’)
– nutritional
– foreign material
– sterile nodular (idiopathic) - Xanthoma
What non-infectious inflammatory masses are associated with calcium?
- Calcinosis cutis
- calcinosis circumscripta
What non-infectious inflammatory masses are associated with extravasated blood?
- Haematoma
- Seroma
What non-infectious inflammatory mass is associated with amyloid?
- Nodular cutaneous amyloidosis
What non-infectious inflammatory masses are idiopathic?
- Canine juvenile granulomatous dermatitis (‘puppy strangles’)
- Sterile nodular granuloma and pyogranuloma
- Nodular dermatofibrosis in GSDs (linked with renal carcinoma)
- Canine cutaneous histiocytosis
Urticaria, angiogenic oedema (angioedema) - causes
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
How common/rare are urticaria and angioedema in cats & dogs?
§ Dogs - uncommon
§ Cats – rare (insect sting often -> regional oedema of forelimb)
Urticaria - CS
- Localised/generalised wheals, +/- pruritic
- Hair tufts over areas of swelling (d/d folliculitis in dog)
Angioedema CS
§ 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
Urticaria and angioedema tx
- 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
What is calcinosis cutis?
= inappropriate deposition of calcium/phosphate in skin/subcutis
-> gritty white deposits, often with surrounding inflammation
3 causes of calcinosis cutis
- 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
What is a haematoma?
= Loss of blood from damaged/ruptured blood vessel in/under skin
Haematoma causes
§ Usually due to trauma
§ occasional clotting factor deficiencies/toxic causes – look for
other signs, history
Haematoma - cytology
- initially cytology is same as blood smear (though no platelets)
- macrophages (engulfing rbcs) +/- fibroblasts may appear with time
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
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.
Seroma FNA
- Straw-coloured/blood-tinged fluid
Seroma ddx
§ Haematoma
§ Abscess
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.
Arthropod bite granuloma cytology
- consistent with an inflammatory lesion
Arthropod bite granuloma - CS
- Small diameter
- Firm
- Ill-defined
- Erythematous
- Nodule
- Central black mark
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)
What is panniculitis?
= inflammation of s/c fat
Panniculitis presentation
- Presents as nodules (single/multiple) +/- draining sinuses
- Easily confused with bacterial abscess
- Can be sterile or of infectious origin
Panniculitis diagnosis
§ FNA – pyogranulomatous inflammation with background fat
Panniculitis biopsy
§ Take samples for histopathology and bacterial and fungal tissue culture - important to rule out infection as initial step.
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
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
Is the skin the most common site for neoplasia in dogs/cats?
- yes (25-58% of all neoplasms)
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
Are most canine skin tumours benign or malignant?
§ Most benign (approx 2/3)
§ Cured with wide local excision
§ Histiocytoma and papilloma may regress spontaneously
Malignant canine skin tumours
§ Mast cell tumour (11% total)
§ Squamous cell carcinoma (SCC) (1%)
§ Malignant melanoma (3%)
§ Soft tissue sarcomas (4%)
§ Epitheliotropic lymphoma
Most common canine skin tumours
§ Lipoma – most common
§ Sebaceous gland tumours (6-21%)
§ Mast cell tumour (11%)
§ Histiocytoma (10%)
§ Basal cell tumour (4-11%)
Are most feline skin tumours benign or malignant?
§ Most malignant (approx 2/3)
Most common feline skin tumours
§ Fibrosarcomas (25%)
§ Squamous cell carcinomas (SCC) (17%)
§ Basal cell tumours (15%)
§ Mast cell tumours (7%)
Are most skin neoplasias painful or painless? Fast or slow growing?
- Most are painless and slow-growing
Which neoplasms present as multiple nodules?
§ epitheliotropic/primary cutaneous lymphomas
§ papillomas
§ malignant tumours that metastasise to skin
§ basal cell carcinoma in cats
Are epithelial tumours usually superficial or deeper?
– usually superficial and
exophytic (ie grow out from epithelial surface)
Are mesenchymal/round cell/adnexal tumours superficial or deeper?
– usually intradermal or s/c, and endophytic (i.e. grow inwards)
Epithelial cell tumour FNA cytology
§ High yield, cells associated with one another, rafts, sheets, acini, cuboidal, columnar
Spindle/mesenchymal cell tumour FNA cytology
§ Low yield, spindle shaped cells, usually single but may be in association/sheets, may be “matrix”
Round cell tumour FNA cytology
§ High yield, discrete round cells, not adherent
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
Characteristics of epithelial cell tumours
- Many types
- Most benign
- Most slow-growing
- Most cured by wide surgical excision
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
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
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
Melanocytic cell tumour examples
- Melanoma
– Benign dermal
– Malignant
Use of skin biopsy and histopathology
§ to confirm putative diagnosis from FNA
§ where FNA is inconclusive
Elliptical incisional skin biopsy
§ Include margin
§ Take from representative area
§ Ensure to remove whole biopsy tract when mass removed
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
MCT - excision
Needs wide excision:
§ with minimum 2cm margins
§ down to and including muscle or fascial plane below tumour
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
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
PARR testing for neoplasia
= PCR for antigen-receptor rearrangement
- To distinguish neoplastic from inflammatory populations, e.g. in lymphoma
Tx options for neoplasia
- Surgery – most common modality
- Chemotherapy
- Radiotherapy
Principles of skin tumour excision
Choice of margin is paramount: wider margins needed for more infiltrative tumours
What are the natural barrier to tumour spread?
- collagen-rich, relatively avascular structures (eg fascia, tendons, ligaments, cartilage)
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
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
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
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
3 golden rules to the approach to cancer cases
- Establish the diagnosis (type and grade of tumour)
- Establish the extent/stage of the disease
- Investigate any complications
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
Sebaceous gland tumours - why type of tumour? solitary or multiple?
- epithelial
- solitary or multiple
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
Sebaceous gland tumours - what are they often referred to as?
§ Often referred to (erroneously) as ‘warts’
Sebaceous gland tumours - tx
§ If slow-growing and well-circumscribed, may leave and monitor
§ Excise if any change or traumatised
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
Basal cell tumour - why type of tumour?
- epithelial
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
Basal cell tumour in dogs - characteristics & tx
§ Usually benign, slow-growing.
§ Wide excision to cure
Canine papillomas (warts) - characteristics/presentation
Young dogs, multiple lesions
§ Mouth, lips, eyes – smooth, shiny plaques or papillated lesions
§ Footpads - firm, hyperkeratotic, often hornlike lesions
Canine papillomas (warts) - why type of tumour?
- epithelial
Canine papillomas (warts) - cause & spread
- Caused by papilloma viruses
- contagious via direct/indirect contact
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
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
Pigmented viral plaques - why type of tumour?
- epithelial
Perianal (hepatoid) gland tumour in dogs - benign or malignant?
§ Adenomas/hyperplasia usually (benign); occasionally malignant
Perianal (hepatiod) gland tumour in dogs - why type of tumour?
- epithelial
Perianal (hepatoid) gland tumour in dogs - cause?
§ Usually androgen-dependent
Perianal (hepatoid) gland tumour in dogs - signalment
§ Usually older male, but <25% in females
§ In entire and neutered animals
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
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)
Lipoma - why type of tumour?
- mesenchymal
Lipoma - signalment
- Common in dog, especially if female, obese
Lipoma - presentation
- usually on trunk
- dermal or sc
Lipoma - 2 forms
§ Non-infiltrating – usual form - encapsulated, soft, moveable
§ Infiltrating variant – uncommon
Both benign
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
Spindle cell sarcomas - why type of tumour?
- mesenchymal
Spindle cell sarcomas - prevalence
§ Relatively common in dog and cat
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
Spindle cell sarcomas - diagnosis
§ Diagnosis on biopsy
– NB poor exfoliation on FNA (except perivascular wall tumours)
Spindle cell sarcomas - tx
§ Wide-radical excision, if possible, but frequently recur as incompletely excised
§ Or cytoreductive surgery + radiotherapy
§ Chemotherapy of little value
Feline fibrosarcoma - why type of tumour?
- mesenchymal
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
MCT - why type of tumour?
- round cell
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
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
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)
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
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
What grade are the majority of MCT?
- Grade II
Tx of well/intermediately-differentiated MCT (grade I/II) with no evidence of metastasis
- surgical excision
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
Tx of metastatic dz of MCT or poorly differentiated MCT (grade III)
- surgery if small and no metastasis - risk and not recommended
- radiotherapy?
- chemotherapy?
Feline MCT - presentation
§ Most commonly on skin
§ Lesions usually solitary, well circumscribed nodules/plaques, alopecic
§ Occasional visceral lesions (spleen, intestine) -> vomiting, anorexia
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)
Feline MCT - tx
§ Surgery – treatment of choice for solitary masses
§ Chemotherapy? – questionable justification unless tumour aggressive, as cats rarely die of MCTs
Primary cutaneous lymphoma - why type of tumour?
- round cell
Primary cutaneous lymphoma - 2 clinical presentations
- Epitheliotropic lymphoma (mycosis fungoides)
(usually T-cell origin) - Non-epitheliotropic lymphoma Less common than 1. (T- or B-cell origin)
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
Non-epitheliotropic lymphoma - manifestations
§ Foci of erythroderma, crusting, ulceration
§ Multiple dermal nodules/erythematous plaques
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
Primary cutaneous lymphoma - prognosis/management
Non-epitheliotropic lymphoma
- Rapid metastasis, grave prognosis
Epitheliotropic lymphoma
- Chronic, may wax/wane initially
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?
Canine cutaneous histiocytoma - why type of tumour?
- round cell
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
Canine cutaneous histiocytoma - FNA
§ Histiocytes (round cells) on FNA – d/d MCT
Canine cutaneous histiocytoma - management
§ Frequently resolve spontaneously – do not use immunosuppressive drugs as may slow regression
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
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
Cutaneous cysts - definition
§ epithelium-lined cavity containing fluid or solid material
Cutaneous cysts - forms
In skin, usually lined with adnexal epithelium: eg
§ Follicular cysts -> cornified debris
§ Apocrine cysts -> apocrine secretions
§ Sebaceous cysts -> sebaceous secretions
Cutaneous cysts - presentation
§ Well-circumscribed; usually solitary, sometimes multiple
§ Some with central pore
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
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
What is emphysema?
- air under the skin
Urticaria vs angioedema
- urticaria = hives
- angioedema = whole body swells up
