Cutaneous masses: workshop

Question 1

when investigating skin mass- what are generally the first diagnostic tests done

Answer 1

cytology- usually FNA
tissue biopsy - histopath

Question 2

what is angioedema

Answer 2

Localised/generalised large oedematous swelling, usually involving head
Potentially fatal if involves airways
Associated with anaphylactic shock on rare occasions

Question 3

Treatment for urticaria

Answer 3

Many cases of urticaria resolve spontaneously in 12-48h
dex IV in acute cases
adrenaline if signs of analphylaxis
avoid cause if known

Question 4

Descrieb Calcinosis cutis

Answer 4

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

Question 5

List 3 causes of calcinosis cutis

Answer 5

dystrophic calcification
metastatic calcification
idiopathic

Question 6

what do we see on cytology with a haematoma

Answer 6

initially cytology is same as blood smear (though no platelets). Macrophages (engulfing rbcs) +/- fibroblasts may appear with time.

Question 7

describe management of haematoma

Answer 7

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.

Question 8

what is a seroma

Answer 8

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.
FNA: Straw-coloured/blood-tinged fluid

Question 9

management of seroma

Answer 9

conservative unless refractory or causing wound distruption
repeasted drainage if size causing discomfort
if severe surgical debridement

Question 10

what do arthropod-but granuloma look like

Answer 10

1cm diameter, firm, ill-defined erythematous nodule with central black mark

Question 11

management of arthropod-bite granuloma

Answer 11

check no evidence of retained arthropod
?short course of steroids
If not resolving, consider surgical removal and submission for histopathology and tissue culture to confirm diagnosis

Question 12

diagnosis of panniculitis

Answer 12

FNA- pyogranulomatous inflammation with background fat
Biopsy- important to rule out infection as initial step

Question 13

if you can’t identify/ correct cause of panniculitis (solitary and multifocal lesion) what should you do

Answer 13

Solitary lesion —> surgical excision if possible

Multifocal lesion —> immunosuppressive therapy

Question 14

what neoplasia can occur in younger animals

Answer 14

histiocytoma

Question 15

T/F most canine skin tumours are malignant

Answer 15

False- 2/3 benign

Question 16

T/F most feline skin tumours are malignant

Answer 16

True - 2/3

Question 17

what is the most common canine skin tumour

Answer 17

lipoma

Question 18

what is the most common feline skin tumour

Answer 18

fibrosarcomas

Question 19

decribe what is seen on cytology with epithelial neoplasia

Answer 19

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

Question 20

what is seen on cytology with round cell tumours

Answer 20

High yield, discrete round cells, not adherent

Question 21

what is seen on cytology with spindle/ mesenchymal cell tumour

Answer 21

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

Question 22

Describe Elliptical incisional biopsy

Answer 22

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

Question 23

Describe Elliptical excisional biopsy

Answer 23

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!

Question 24

List the 4 rules to approaching a cancer cases

Answer 24

1. Establish the diagnosis (type and grade of tumour)
2. Establish the extent/stage of the disease
3. Investigate any complications
4. greatest chance of cure lies with the primary surgery

Question 25

treatment of sebaceous gland tumours

Answer 25

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

Question 26

what is the most common pigmented tumour in cats

Answer 26

basal cell tumour

Question 27

describe basal cell tumours

Answer 27

solid, ulcerative or cystic
Aggressive characteristics on cytology/histopathology but low-grade behaviour usually
Excise with as wide a margin as possible

Question 28

Management of canine papillomas (warts)

Answer 28

Usually allow to resolve spontaneously, though new ones may develop
Surgery if causing problems

Question 29

describe pigmented viral plaques

Answer 29

Especially French bulldogs, pugs - are viral papilloma’s
May not spontaneously resolve and occasionally –> SCC
Care re concurrent use of immunosuppressive drugs…

Question 30

what animals do perianal (hepatoid) gland tumour occur in

Answer 30

Usually older male, but <25% in females
In entire and neutered animals
often androgen-dependent

Question 31

treatment of perianal (hepatoid) gland tumour

Answer 31

Hormonal – surgical or chemical castration – most will regress
If necessary, wide surgical excision

Question 32

what should you always do with a possible lipoma

Answer 32

FNA to confirm

Question 33

what are spindle cell sarcomas

Answer 33

mesenchymal
solitary, slow-growing masses
May appear well-circumscribed but actually highly infiltrative
Low rate of metastasis
poor exfoliation on FNA

Question 34

Treatment of spindle cell sarcoma

Answer 34

wide-radial excision if possible but frequently recur
OR
cytoreductive surgey and radiotherapy

Question 35

what happenes when mast cells degranulate

Answer 35

histamine is released -> this can cause erythema, pruritus, oedema –> the mass may fluctuate in size

they can also release heparin and proteases

Question 36

what is Dariers sign

Answer 36

local pruritus, erythema, wheal after rubbing lesion

Question 37

what are the 2 types of primary cutaneous lymphoma

Answer 37

Epitheliotropic lymphoma (T cell origin)
Non-epitheliotropic lymphoma (T or B cell origin)

Question 38

treatment of primary cutaneous lymphoma

Answer 38

chemothepary
surgery if solitary/ localised
radiotherapy?

Question 39

prognosis of primary cutaneous lymphoma

Answer 39

Non-epitheliotropic lymphoma- Rapid metastasis, grave prognosis
Epitheliotropic lymphoma- Chronic, may wax/wane initially

Question 40

describe Canine cutaneous histiocytoma

Answer 40

common rapidily growing well demarcated masses
in young dogs- common on extremities

Question 41

describe melanomas

Answer 41

well-defined deeply-pigmented flat/plaque/dome-shaped lesions in pigmented skin
most benign –> wide excision
on non-haired skin and digits- more likely malignant

Question 42

tteatment of melanomas

Answer 42

Excise with wide margins where possible

Question 43

what is a cutaneous cyst

Answer 43

epithelium-lined cavity containing fluid or solid material

Question 44

treatment of cutaneous cyst

Answer 44

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

Question 45

what is a dermoid cyst

Answer 45

congenital defect- e.g. Rhodesian ridgeback
Cysts dorsal midline neck/trunk
Filled with hair/keratinous material
may extend to dura mater

Question 46

Decsribe injection site sarcomas

Answer 46

type of feline fibrosarcoma
usually intrascapular
consult oncologist after biopsy but before surgery

Question 47

Treatment of mast cell tumours

Answer 47

surgery if possible
chemotherpay- TKIs, protein kinase C activators