Mammary Gland Disease Flashcards
mammary masses more malignant in cats or dogs?
- dogs 50% malignant, of those 50% metastasise
- cats more aggressive, 90% malignant, of those 80% metastasise
Mammary masses more common in dogs or cats? why?
- dogs
- more cats neutered
risk factors of mammary tumour?
- ^ age
- intact queen/bitch
- obesity early on in life
- P4 treatment (not common nowadays, used to be used for skin tx)
- benign tumours pdf for malignant mammary tumours
What age should neutering be carried out by for protective effects?
- < 3rd season for bitch
- <1 year for queen
where should masses be checked for on PE?
- all glands
- inguinal and axillary regions
- rectal (sublumber LNs)
- inflammaotry carcinoma not a discrete mass (feels swollen, not mobile - v. aggressive)
- feline tumours often not a discrete mass (>50% multiple masses, > 25% ulcerated) as more aggressive form of neoplasia
3 types of benign mammary tumour?
- adenoma (glandular)
- mesenchymal
- mixed tumour
3 types of malignant mammary tumour?
- carcinoma (subtypes of carcinoma: solid, tubular, papillary, inflammatory - based on path report)
- sarcoma
- carcinosarcoma
DDx for mammary lumps?
- mastitis (only if pregnant or eeding puppies)
- galactostasis (when puppies being weaned)
- galacatorrhoea (in pseudopregnancy)
- mammary hyperplasia (esp cats, will resolve spontaneously, spaying resolves)
- cutaneous/subcutaneous tumour (eg.MCT)
Staging system for mammary tumours. Diagnostics for this?
> TMN
- tumour size (>3cm)
- regional lymph node
- distant metastasis (lung)
PE
Chest radiographs
ABdominal US
FNA enlarged/hard LN (inflam/skin tumour/mammary tumour)
Haem/biochem (check anaesthesia risk liver/kidney, concurrent disease)
surgical biopsy (incisional [inoperable eg. inflam carcinoma] v excisional [well defined, mobile, small with good margins]) usually incisional first
WHat may occour 2* to sublumbar LN enlargement?
- compresses colon -> constipation
- aspirate LN to see if mets
Medical Tx
? - chemo?
? - tamoxifen or other hormone-R Tx? Side effects: bleeding, pyo
- radiotherapy NOT used in cats/dogs
WHat iss the best Tx choice for majority of mammary tumours?
- surgical
- EXCEPTION inflammatory carcinoma (not affected by surgery, likely not much time left)
- EXCEPTION metastasis (LNs/lungs)
> do not delay surgery (assume all malignant)
How may mammary glands do cats and dogs have?
Cats 4
DOgs 5
What are the inguinal LNs closely associated with?
Most caudal mammary gland
What are the axillary LNs assocaited with?
Not really - quite far cranial, have to go out of your way to remove
How do glands drain lymph and blood?
Cranial drain forward, caudal backwards (generally)
- some cross over
What will have to be ligated when removed glands/LNs? What post-op complications may occour because of this?
- caudal superficial epigastric artery (passes thorugh inguinal canal) + lymphatics
- > oedematous hind limb (will resolve)
Outline mastectomy surgery
- excise with >2cm normal margins
- excise fasia or muscle if necessary
- place drain for dead space
- submit EACH tumour for pathology
WHat type of surgery is usually performed on cats and dogs?
- DOGS: complete but not radical surgery (only need to remove mass with margins)
- CATS: unilateral (all glands on one side) mastectomy MINIMUM (all mammary tissue removed.
What is the least invasive surgery
Lumpectomy
What is a simple mastectomy?
Remove one gland with the mass (ensure >2cm margins)
WHat is a regional mastectomy?
- removal of multiple glands +- regional LNs
- cranial or caudal (caudal common)
What is the minimum surgery to perform on cats? When is this also performed in dogs?
- unilateral mastectomy
- scar from previous surgery (need margins around scar)
How should bilateral mastectomy be performed?
- staged procedure
- unilateral mastectomy first, leave to heal, 2* surgery 3-4 weeks later.
How should large wounds be sutured?
- place towel clamps first
- suture fascia to take tension (skin should not take tension)
Where should the cuadal superifical epigastric be ligated?
- close to tumour ( not close to body as may ligate other vessels)
POtential post-op complications?
- seroma (self resolving)
- wound breakdown/infection (10%)
- hindlimb oedema (5-10% self resovling)
- recurrence or mets
See lecture notes for prognosis in dogs
WHat may be tested for with IHC?
- receptors (more malignant tumours lose receptors)
- not commonly performed
What features are NOT prognostic in dogs?
- no. of tumours
- site of tumour
- type of surgery (as long ascomplete)
- OHE at time of surgery (controvesial)
WHen should neutering be performed if being carried out at same time as tumour removal?
BEFOER tumour removal (dont take neoplastic cells into abdomen)
WHat is the mean survival of inflammatory carcinoma?
30d
