Cutaneous skin masses Flashcards
Swellings of non-dermatologic origin
- Hernias
- Oedema
- Bursitis
- Emphysema
- Mammary tumours
What is an oedema?
○ Ill-defined, soft, painless swelling from
○ E.g. R sided heart failure, hypoalbuminemia
○ Pits on pressure
○ Clear fluid on FNA
What is emphysema?
Sounds like crisp packet
Gas in subcutaneous tissue
Caused by:
□ Severe respiratory disease or lung puncture
□ Introduction of air through cutaneous wound
□ Rumenotomy or rumen cannulisation
□ Clostridial infections
Classifications of skin masses
Inflammatory
Neoplastic
Cystic
Inflammatory skin masses
○ Infectious
Bacterial infectious
Fungal infection
Demodex
○ Non-infectious
Urticaria/angioedema
Eosinophilic granuloma
Tick/insect bite granuloma
Sterile panniculitis
Haematoma
Seroma
Neoplastic skin masses
○ Epithelial neoplasm
○ Mesenchymal neoplasm
○ Round cell neoplasm
What is a cyst?
Cavity lined with epithelium which produces material into the cavity
Infectious Inflammatory Skin masses
- Abscess/ cellulitis
○ E.g. post trauma/foreign body/ bite
○ Esp farm animal, cat. Also rabbits, secondary to dental disease - Furunculosis
○ E.g. staphylococcal deep pyoderma, Demodex - Bacterial granulomas
○ Mycobacteria
○ Actinobacillus, Nocardia, Actinomyces - Deep/subcutaneous or systemic fungal granuloma
Non-Infectious Inflammatory Skin masses
- Urticaria, angioedema (esp horse> dog >cat)
○ Degranulation mast cells causing oedema
Painless
Pit on pressure
○ Can be allergic (type I or III) or non-immunologic cause
○ Urticaria = wheals (+/- pruritus)
○ Angioedema = large oedematous swelling, usually involving head – can be fatal - Seroma
○ Accumulation of serum under skin
○ Painless, non-pitting
○ Frequently occurs post-surgery - Haematoma
○ Loss of blood from damaged/ruptured blood vessels under skin
○ Painless, non-pitting
○ Usually due to trauma, occasionally to clotting problems
○ Others, e.g eosinophilic granulomas, tick/insect bite granulomas, sterile panniculitis
Neoplasms
- Most commonly in older animals (a few exceptions)
- Uncommon in farm animals
- Horse
○ Especially melanomas (grey horses)
○ Sarcoids - Dogs
○ Skin neoplasms very common
○ E.g. lipomas, sebaceous adenomas, mast cell tumours - Cats
○ Neoplastic skin masses less common
Cysts
- Epithelial-lined cavity, containing fluid or solid material produced by cells of cyst lining
- Smooth, well-circumscribed
- Fluctuant/solid
○ Dependent on nature of contents
How to decide what the mass is
- Signalment
- History – general, dermatological
- Clinical examination – general, dermatological
- Formulate list of ranked d/ds
○ Investigate d/ds using
Cytology
Tissue biopsy - histopathology +/- tissue culture
Signalment considerations
○ Species
E.g. abscess common in cat, cattle, rabbits
Skin neoplasms common in older dog
○ Breed/colour
E.g. Melanomas in grey horses
Mast cell tumours common in boxers
○ Age
Neonate – umbilical abscess
History considerations
○ General history
History of trauma/fight/surgery -> abscess/cellulitis, haematoma, seroma
Recent injection
□ Abscess, panniculitis
Systemic signs
□ Paraneoplastic
E.g. +/- haematemesis with mast cell tumour
□ Respiratory signs, weight-loss, lethargy
Systemic /metastatic neoplasia, systemic fungal infections
□ Depression, inappetance – some microbial infections/abscess
○ Dermatological history
Speed of onset of mass
Prior history of neoplasia?
General clinical exam considerations
Pyrexia
□ Often with systemic/severe cutaneous microbial infection, abscess
Peripheral lymphadenopathy
□ Metastatic spread of neoplasm, reaction to infection/inflammation
Other systemic abnormalities
□ May influence diagnostic/treatment choice
□ May link directly to mass
Animals with lung metastases may have no clinical signs
Non-dermatological swelling?
□ Bursa?
□ Joint swelling?
□ Hernia?
