Mammary gland disease

Question 1

mammary neoplasia - incidence

Answer 1

bitch - common, 35-50% malignant - 50% metastasize

queen - less common, 90% malignant - 80% metastasize

Question 2

mammary neoplasia - cause

Answer 2

Hormonal influence likely: prevented by neutering
Canine: oestrogen & progesterone receptors: benign (90%) > malignant (50%) > metastatic (0%)
Feline: progesterone receptors

Question 3

mammary neoplasia - risk factors

Answer 3

Increasing age: average 9.5yrs 
Intact bitches/queens 
Obesity early on in life 
Progestagen treatment 
Benign tumours pdf for malignant tumours

Question 4

mammary neoplasia - clinical presentation

Answer 4

Physical exam
Wide variation in masses
Thorough/systematic examination of glands
Rectal exam, palpate lymph nodes
inflammatory carcinoma not a discrete mass
feline tumours often not a discrete mass
Palpate inguinal and axillary regions
Signs from metastatic disease rare

Question 5

Mammary tumour types - benign

Answer 5

Adenoma
Mesenchymal tumour
Mixed tumour

Question 6

Mammary tumour types - malgnant

Answer 6

Carcinoma: solid, tubular, papillary, inflammatory
Sarcoma
Carcinosarcoma

Question 7

differential diagnosis

Answer 7

Mastitis 
Galactostasis 
Galactorrhoea 
Mammary hyperplasia 
Cutaneous/subcutaneous tumour

Question 8

diagnostic tests

Answer 8

Haematology, biochemistry +/- coagulogram
FNA - mastitis/inflammatory carcinoma, rule out skin tumours
Surgical biopsy for definitive diagnosis - Excisional biopsy common, incisional biopsy for inoperable tumours
?Immunohistochemistry for hormone receptors

Question 9

medical treatment

Answer 9

Never a sole treatment

Chemotherapy?

Question 10

surgical treatment

Answer 10

Treatment of choice for all tumours - except inflammatory carcinoma, not recommended if distant mets
Best to assume all masses are malignant
Do not delay surgery

Question 11

surgery

Answer 11

Excise with >2cm normal margins
Excise fascia or muscle if necessary
Place drain if extensive dead space
Submit each tumour for pathology + record site
Dogs - Complete but not radical surgery
Cats - Unilateral mastectomy is the minimum recommendation

Question 12

lumpectomy

Answer 12

removal of a mass on the abdomen

Question 13

simple masectomy

Answer 13

removal of a single mammary gland

Question 14

regional masectomy

Answer 14

removal of multiple mammary glands and/or adjacent lymph nodes

Question 15

unilateral masectomy

Answer 15

removal of an entire row of mammary glands and/or adjacent LN’s

Question 16

bilateral masetomy

Answer 16

removal of both rows of mammary glands and/or adjacent LN’s

Question 17

postoperative care

Answer 17

Analgesia 
Abdominal bandage 
Drain management (aseptic technique)

Question 18

complications

Answer 18

Seroma 
Wound dehiscence 
Wound infection 
Hindlimb oedema 
Recurrence of tumour or metastatic spread

Question 19

survival - dogs

Answer 19

Inflammatory carcinomas mean survival @ 30days
Malignant, incompletely excised 75% mortality <1yr
Malignant, completely excised, no mets expected to live 1-2 yrs
Malignant, completely excised, mets median survival 5 months
Benign tumours complete excision is curative

Question 20

survival - cats

Answer 20

Malignant tumour overall median <1yr