Mammary Gland Disease

Question 0

mammary masses more malignant in cats or dogs?

Answer 0

• dogs 50% malignant, of those 50% metastasise

- cats more aggressive, 90% malignant, of those 80% metastasise

Question 1

Mammary masses more common in dogs or cats? why?

Answer 1

• dogs

- more cats neutered

Question 2

risk factors of mammary tumour?

Answer 2

• ^ 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

Question 3

What age should neutering be carried out by for protective effects?

Answer 3

• < 3rd season for bitch

- <1 year for queen

Question 4

where should masses be checked for on PE?

Answer 4

• 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

Question 5

3 types of benign mammary tumour?

Answer 5

• adenoma (glandular)
• mesenchymal
• mixed tumour

Question 6

3 types of malignant mammary tumour?

Answer 6

• carcinoma (subtypes of carcinoma: solid, tubular, papillary, inflammatory - based on path report)
• sarcoma
• carcinosarcoma

Question 7

DDx for mammary lumps?

Answer 7

• 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)

Question 8

Staging system for mammary tumours. Diagnostics for this?

Answer 8

> 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

Question 9

WHat may occour 2* to sublumbar LN enlargement?

Answer 9

• compresses colon -> constipation

- aspirate LN to see if mets

Question 10

Medical Tx

Answer 10

? - chemo?
? - tamoxifen or other hormone-R Tx? Side effects: bleeding, pyo
- radiotherapy NOT used in cats/dogs

Question 11

WHat iss the best Tx choice for majority of mammary tumours?

Answer 11

• surgical
• EXCEPTION inflammatory carcinoma (not affected by surgery, likely not much time left)
• EXCEPTION metastasis (LNs/lungs)
  > do not delay surgery (assume all malignant)

Question 12

How may mammary glands do cats and dogs have?

Answer 12

Cats 4

DOgs 5

Question 13

What are the inguinal LNs closely associated with?

Answer 13

Most caudal mammary gland

Question 14

What are the axillary LNs assocaited with?

Answer 14

Not really - quite far cranial, have to go out of your way to remove

Question 15

How do glands drain lymph and blood?

Answer 15

Cranial drain forward, caudal backwards (generally)

- some cross over

Question 16

What will have to be ligated when removed glands/LNs? What post-op complications may occour because of this?

Answer 16

• caudal superficial epigastric artery (passes thorugh inguinal canal) + lymphatics
• > oedematous hind limb (will resolve)

Question 17

Outline mastectomy surgery

Answer 17

• excise with >2cm normal margins
• excise fasia or muscle if necessary
• place drain for dead space
• submit EACH tumour for pathology

Question 18

WHat type of surgery is usually performed on cats and dogs?

Answer 18

• 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.

Question 19

What is the least invasive surgery

Answer 19

Lumpectomy

Question 20

What is a simple mastectomy?

Answer 20

Remove one gland with the mass (ensure >2cm margins)

Question 21

WHat is a regional mastectomy?

Answer 21

• removal of multiple glands +- regional LNs

- cranial or caudal (caudal common)

Question 22

What is the minimum surgery to perform on cats? When is this also performed in dogs?

Answer 22

• unilateral mastectomy

- scar from previous surgery (need margins around scar)

Question 23

How should bilateral mastectomy be performed?

Answer 23

• staged procedure

- unilateral mastectomy first, leave to heal, 2* surgery 3-4 weeks later.

Question 24

How should large wounds be sutured?

Answer 24

• place towel clamps first

- suture fascia to take tension (skin should not take tension)

Question 25

Where should the cuadal superifical epigastric be ligated?

Answer 25

• close to tumour ( not close to body as may ligate other vessels)

Question 26

POtential post-op complications?

Answer 26

• seroma (self resolving)
• wound breakdown/infection (10%)
• hindlimb oedema (5-10% self resovling)
• recurrence or mets

Question 27

See lecture notes for prognosis in dogs

Question 28

WHat may be tested for with IHC?

Answer 28

• receptors (more malignant tumours lose receptors)

- not commonly performed

Question 29

What features are NOT prognostic in dogs?

Answer 29

• no. of tumours
• site of tumour
• type of surgery (as long ascomplete)
• OHE at time of surgery (controvesial)

Question 30

WHen should neutering be performed if being carried out at same time as tumour removal?

Answer 30

BEFOER tumour removal (dont take neoplastic cells into abdomen)

Question 31

WHat is the mean survival of inflammatory carcinoma?

Answer 31

30d