Non-neoplastic masses Flashcards
What is a haematoma?
- Loss of blood from damaged/ruptured blood vessel in/under skin
- Usually due to trauma: but
- occasional clotting factor deficiencies/toxic causes – look for other signs, history
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 – see Ear Surgery lecture
Check this out?
What are inflammatory infectious causes of non-neoplastic masses?
Bacterial
- Abscess (post-traumatic/foreign body)
- Bacterial cellulitis
- Furunculosis secondary to Staph folliculitis +/or Demodex
- Actinomyces/Nocardia/ Actinobacillus
- infection (zoonotic!)
- Cutaneous mycobacterial lesions (zoonotic!)
- Feline mycobacterial granuloma (zoonotic!)
- Cutaneous bacterial granuloma
Fungal – many zoonotic!
- S/c dermatophytic granuloma (‘kerion’)
- Sporotrichosis
- Opportunistic s/c fungal infections
- Cutaneous involvement of systemic mycosis
Protozoal
- Leishmaniasis – zoonotic!
Others
- Rhabditic dermatitis
- Protothecosis
- Pythiosis
Case 1
Think about this case:
6 yo MN DSH cat
Firm swelling on right cheek, present for 5 days
Palpation of mass is resented
Clinical examination otherwise unremarkable. Temperature 39.2C
Give your ranked differential diagnosis list. What investigations would you perform?
D/d
- Cat bite abscess
- Neoplasm +/- secondary infection
- Abscess for other reason: dental disease/foreign body?
- Haematoma: ?post-RTA/?clotting defect
Diagnosis
- FNA of contents; examine contents grossly and cytologically
- Examine for evidence of dental disease
- GA biopsy if suspect neoplasm
Cytology shows:
Neutrophils – with cocci
Acute inflammation
Diagnosis: Abscess
What is this?
Furunculosis
Furunculosis = rupture of hair follicles associated with severe inflammation
May present as a swelling +/- draining sinus tract
May be caused, for example, by deep bacterial pyoderma or demodicosis – establish cause!
NB inflammation may continue after microbes/parasites are killed, as keratinised material from ruptured follicle/hair are released into the dermis à foreign body reaction.
Name non-infectious causes of inflammation?
What causes Urticaria, angioedema?
- Degranulation of mast cells or basophils –> oedema (painless, pits on pressure)
- Causes:
- Immunological
- Type I or III hypersensitivities
- Mast cell tumours (rare)
- Immunological
- Non-immunological
- Physical forces (pressure, sunlight, heat, exercise)
- Genetic abnormalities
- Drugs/chemicals (incl food)
- Venemous insects
- Plants
COMMON IN HORSES
Dogs - uncommon
Cats – rare (insect sting often à regional oedema of forelimb)
How can urticaria and angiodema appear?
Urticaria
- Localised/generalised wheals, +/- pruritic
- Hair tufts over areas of swelling (d/d folliculitis in dog)
Angioedema
- Localised/generalised large oedematous swelling, usually involving head
- +/- pruritus, exudation
- Potentially fatal if involves airways
- Rarely associated with anaphylactic shock
How you would treat urticaria and angioedema in a dog?
Urticaria, angioedema: NSAIDs, corticosteroid
What is this?
Calcinosis cutis
=inappropriate deposition of calcium/phosphate in skin/subcutis
–> gritty white deposits, often with surrounding inflammation
Dystrophic calcification (deposition in injured, degenerating or dead tissue)
- eg HAC
Metastatic calcification (deposition associated with altered serum levels of calcium/phosphorus)
- eg chronic renal disease
Idiopathic
- eg Calcinosis circumscripta
When can cause Dystrophic calcification?
Deposition in injured, degenerating or dead tissue.
eg seen in HAC
What are the consequences of Metastatic calcification?
Deposition associated with altered serum levels of calcium/phosphorus due to hypercalcaemia of malignancy.
eg causing chronic renal disease due to calcium deposited in tubules
Think about this case:
- 10yo ME Staffordshire Bull Terrier
- Slightly fluctuant swelling on pectoral region. Present for 3 days at site of recent removal of subcutaneous mass
- Minimal discomfort on palpation
- Temperature 38.6C
Give your top 3 differential diagnoses and state how you would distinguish between them?
D/d
- Seroma
- Haematoma
- Infection: abscess/cellulitis
Diagnosis FNA for gross and cytological analysis
- Seroma: straw-coloured/blood-tinged fluid
- Infection: Abscess: purulent aspirate if abscess. High numbers neutrophils, bacteria on cytology if infection (abscess or cellulitis)
- Haematoma: initially cytology is same as blood smear (though no platelets). Macrophages (engulfing rbcs) +/- fibroblasts may appear with time.
What is a seroma?
- Accumulation of sterile fluid (filtrate of blood) under a wound
- Fluid straw-coloured/blood-tinged (cytology to d/d haematoma, abscess)
- Soft, non-painful swelling 2-5 days post-surgery (d/d infection!). No heat on palpation.
How should a seroma be managed?
-
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.
Think about this case?
4yo MN English Bull Terrier
1cm diameter, firm, ill-defined erythematous nodule with central black mark
Present on ventrolateral abdomen for 1 week, apparently unchanged
What are your differential diagnoses and how would you investigate further?
D/ds
- Cytology consistent with an inflammatory lesion. No evidence of microbes seen (though does not totally preclude their presence)
- Central black area highly suggestive of arthropod bite granuloma, though difficult to prove (consider time of year, potential exposure) without biopsy
d/d
- Arthropod bite granuloma
- Foreign body reaction
- Localised bacterial infection
- Localised fungal infection
- Other sterile inflammatory disease (rare)
How would you manage an Arthropod-bite granuloma?
Management
- Check no evidence of retained arthropod (esp tick) mouthparts
- Arthropod bite granuloma 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 for 2 weeks minimum before sampling for histology)
