Cutaneous masses and cysts Flashcards
Give examples of skin swellings that have a non-dermatologic origin
Hernias
Oedema
Bursitis
Emphysema
Mammary tumours
Describe the features of an oedematous skin mass
Ill-defined, soft, painless swelling from, e.g. R sided heart failure, hypoalbuminaemia
Pits on pressure
Clear fluid on FNA
What is an emphysema and what causes it?
gas in subcutaneous tissue
crepitant (crackling sound) without pain or swelling
caused by:
- Severe respiratory disease or lung puncture
- Introduction of air through cutaneous wound
- Rumenotomy or rumen cannulisation
- Clostridial infections
What are the classifications of skin masses?
Neoplastic
Cyst
Inflammatory (infectious vs non-infectious)
Give examples of infectious causes of inflammatory skin masses
Bacterial infection
Fungal infection
Demodex
Give examples of non-infectious causes of inflammatory skin masses
Urticaria/angioedema
Eosinophilic granuloma
Tick/insect bite granuloma
Sterile panniculitis
Haematoma
Seroma
Give examples of neoplastic causes of skin masses
Epithelial neoplasm
Mesenchymal neoplasm
Round cell neoplasm
Give examples of types of infectious inflammatory skin masses and their causes
Abscess/cellulitis e.g., post trauma/foreign body
Furunculosis e.g., staphylococcal deep pyoderma, demodex
Bacterial granuloma e.g., mycobacteria, actinobacillus, nocardia, actinomyces
Deep/subcutaneous or systemic fungal granuloma
Give examples of non-infectious inflammatory skin masses
Uticaria, angioedema
Seroma
Haematoma
Others e.g., eosinophilic granuloma, tick/insect bite granuloma, sterile panniculitis
Describe uticaria and angioedema skin masses
esp horse> dog >cat
Degranulation mast cells => oedema
Can be allergic (type I or III) or non-immunologic cause
Urticaria => wheals (+/- pruritus)
Angioedema => large oedematous swelling, usually involving head – can be fatal
Describe seromas
Accumulation of serum under skin
Painless, non-pitting
Frequently occurs post-surgery
Describe haematomas
Loss of blood from damaged/ruptured blood vessels under skin
painless, non-pitting.
Usually due to trauma, occasionally to clotting problems
Give examples of common neoplastic causes of skin masses
Most commonly in older animals
uncommon in farm animals
Horse – melanomas (grey horses), sarcoids
Dogs – skin neoplasms very common - e.g. lipomas, sebaceous adenomas, mast cell tumours
Describe cysts
Epithelial-lined cavity, containing fluid or solid material produced by cells of cyst lining
Smooth, well-circumscribed
Fluctuant/solid
An animal has a history of trauma/fight/surgery. What is the most likely cause of skin masses?
abscess/cellulitis, haematoma, seroma
An animal has had a recent injection. What is the most likely cause of skin masses
abscess, panniculitis
Describe the appearance of cysts on cytology
Contents produced by cyst’s epithelial lining – e.g. sebaceous or keratinized material/squames. Often amorphous appearance. Occasional cholesterol crystals
+/- secondary inflammation if cyst ruptures
