Lumps and Bumps Flashcards
What is botryomycosis?
NOT fungal!
- also called bacterial granuloma, staphylococcal pseudomycetoma
- > nodules and non-healing wounds
What are nodular lesions usually caused by?
- cutaneous neoplasia
- inflammatory process (diffuse or nodular inflam pattern, or panniculitis) usually granulomatous (may be sterile [FB] but usually infection [bacteria/mycobacteria/viral/funghi/parasites])
- trauma
- depositional disease eg. amyloidosis
Diagnositcs for nodular lesions? Exception?
- histology (biopsy)
- cytology (FNA)
- macerated tissue culture
> exception sarcoids where invasive procedures may stimulate further invasion
What is panniculitis?
- inflam subcutaneous fat and connective tissue
- usually infective
Which neoplasia affects the interfollicular epithelium?
- papilloma
- squamous cell carcinoma
What 4 main sites give rise to skin neoplasia?
- epithelium
- mesenchyme
- round cells (MCT, histiocytes, lymphocytes)
- mets
What may appear like a nodule in horses but isnt?
wheals/hives - will be oedematous (pitting)
3 most common skin neoplasia in dogs and cats?
> dogs - hepatoid gland adenoma (perianal, testosterone dependant) - sebaceous adenoma - trichoepithelioma > cats - basal cell tumour - SCC - aprocrine duct/gland/ceruminous gland adenoma
What type of neoplasm will regress on its own?
Histiocytoma
What may epithelial cells in the skin be ‘destined’ to become?
- basal keratinocytes -> squames
- inner and out root sheaths of follicle
- adnexal glands and ducts
Are majority of epithelial tumours malignant?
No - mostly benign
3 tumours of the epidermis
- papilloma (warty, young dogs)
- inverted papilloma
- SCC (white cats face tips, keratin pearls/swirls on histo)
What types of tumour show adnexal differentiation?
- hair follicle
- sebaceous (+ modified sebaceous) glands
- sweat (+ modified) glands
5 hair follicle tumours
- infundibular keratinising acanthoma
- tricholemmoma
- trichoblastoma (=basal cell tumour)
- trichoepithilioma
- pilomatricoma
3 tumours of sebaceous glands/modified sebaceous glands?
- sebacious hyperplasia/adenoma/epithelioma/adenocarcinoma
- hepatoid gland adenoma/adenocarcinoma
- meibomian gland adenoma/epithelioma/adenocarcinoma
4 tumours of sweat glands/modified?
- apocrine gland adenoma/ductal adenoma/adenocarcinoma
- eccrine (atrichial) adenoma/adenocarcinoma
- ceruminous gland adenoma/adenocarcinoma
- anal sac adenoma/adenocarcinoma
Which tumours do not have squamous or adnexal differentiation?
- basal cell tumour (tichoblastoma)
- basal cell carcinoma
Which species has a higher risk of malignant skim neopasia?
Cats (dogs usually benign)
5 types of mesenchymal tumour
- fibrous
- vascular/perivascular
- muscle
- neural and pernineural
- lipcytic
Clinical presentation of mast cell tumours?
- varies massively!!
-single/multiple - small/large
- well demarcated/imfiltrive
- firm/soft
- ulcerated/epithelialised
- oedematous/inflam
- pigmented/non-pigmented
> fluctuant swelling and erythema should ^ suspicion
> affect dermis and subcutis
> usually back half of body (perineum, dital limbs, perpuce)
> Boxers, pugs, weimeranas predisposed - concurrent signs due to histamine, heparin and other vasoactive mediator release: bleeding disorders, immune-mediated thrombocytonpaenia, GI ulceration
Are MCT considered benign?
Should be considered potentially malignant
Diagnostics
- cytology
- imaging
- buffy coats + BM aspirate
> difficult to interpret
Tx MCT
Standard neoplasia surgery, chemo, radiation
- surgery gold stand woith nonode involvement
- intermediate 2cm margins and one deep facial plane
- some dirty margins will not regrow
