Caesarean, mammary and other reproductive surgery Flashcards
Tumours of the ovary - prevalence & signalment
- rare, in both dogs and cats
- infrequently might be because many individuals undergo neutering at a young age
- affected individuals are most frequently older, nulliparous individuals, although teratoma will often occur in younger individuals
Tumours of the ovary - examples
Surface epithelial tumours
- 40-50% of cases
- benign: cystadenoma, papillary adenoma
- malignant: cystadenocarcinoma, papillary adenocarcinoma, undifferentiated carcinoma
Gonadostromal tissue tumours
- 35-50% of cases
- benign: thecoma, luteoma
- malignant: granulosa cell tumour
Germ cell tumours
- 6-20% of cases
- benign: teratoma
- malignant: dysgerminoma, teratoma, carcinoma
Tumours of the ovary - CS
- pyometra
- abnormal oestrus
- vaginal discharge
- secondary sex organ change
- lumbar pain
- presence of an abdominal mass
- enlarged abdomen (presence of effusion and/or mass)
- lethargy
- weight gain or weight loss
Tumours of the ovary - clinical approach
- physical exam
- blood samples
- imaging: radiography, US, CT
- cytology
- biopsy
- often, an incidental finding at the time of OE or OHE
Tumours of the ovary - management
- surgery (OE or OHE)
- ± chemo
Tumours of the uterus and cervix - examples
Benign
- fibroma
- fibroleiomyoma
- leiomyoma
- adenoma
Malignent
- fibrosarcoma
- leiomyosarcoma
- adenocarcinoma
- lymphoma
Tumours of the uterus and cervix - prevalence and signalment
- rare, in both dogs and cats
- infrequency might be because many individuals undergo neutering at a young age
- in the bitch, benign tumours occur with greatest frequency
- in the queen, although very uncommon, malignant tumours are more frequent
Tumours of the uterus & cervix - approach and tx
- similar clinical approach to ovarian tumours
- tx: surgical OHE or hysterectomy in neutered individuals
Tumours of the vagina and vulva - prevalence & signalment
- excluding mammary tumours, vaginal, vestibular and vulval tumours are the most common tumours of the reproductive tract in the bitch
- benign mesenchymal tumours, such as leiomyoma, affect entire, aged bitches
- majority of tumours are seen in nulliparous individuals
- benign smooth muscle tumours account for approx 80-90% of vaginal and vulval tumours reported in bitches
- the growth of many of these benign smooth muscle tumours is associated with ovarian secretion of oestrogen
- the most common malignant tumour of the vagina and vulva is the leiomyosarcoma
- TVT is seen more commonly in females than in males
- tumours of the vulval labia can be associated with any form of cutaneous tumour, particularly SCC and MCT
Tumours of the vagina and vulva - examples
Benign
- leiomyoma
- fibroma
- fibroleiomyoma
- lipoma
Malignant
- leiomyosarcoma
- adenocarcinoma
- transmissible venereal tumour
- SCC
- haemangiosarcoma
- osteosarcoma
- MCT
Tumours of the testicle - prevalence & signalment
- common in the male dog
- usually seen in dogs older than 10y/o
- earlier in cryptorchid animals (20-fold increased risk)
- 3 common types seen are: interstitial cell tumour, seminoma and Sertoli cell tumour
- rarely seen in the tom cat (related to elective castration)
Tumours of the testicle - examples
Gonadostromal tissue tumours
- benign: interstitial cell (Leydig) tumour
- malignant: Sertoli cell tumour
Germ cell tumours:
- benign: teratoma
- malignant: seminoma
Sertoli cell tumour - signs
(sometimes seminomas will cause these signs)
Often produce excess oestrogen, causing the development of feminisation syndrome
- bilaterally symmetrical alopecia
- attractiveness to male dogs
- pendulous prepuce
- gynaecomastia (mammary enlargement, nipple enlargement)
- atrophy of affected testicle
- myelosuppression (anaemia, neutropenia and thrombocytopenia)
Tumours of the testicle - tx
Consists primarily of orchiectomy (castration)
- closed rather than open
- cryptorchid cases might prove more difficult dependent on where the testicle is situated
- often curative
- feminisation signs might take 6w or more to resolve
Tumours of the penis - examples
Benign
- papilloma
Malignant
- SCC
- TVT
- haemangiosarcoma
Tumours of the penis - prevalence
- generally rare in both the dog and cat
- but, TVT is recognised as a relatively common condition in certain parts of the world
- apart from TVT, the majority of penile tumours occur in the older dog
- where TVT is not endemic, SCC is the most common tumour of the penis in the dog
- the prepuce may be affected by any type of skin tumour
— tumours commonly associated with this structure include MCTs, melanomas, etc
Tumours of the penis - CS
CS associated with penile tumours are related to local tissue irritation, infection and bleeding
- licking of prepuce and penis
- haemorrhagic and/or purulent discharge from the prepuce
- haematuria (may be frank blood at the beginning or end of micturition)
- dysuria
- increased frequency of urination
- phimosis
- paraphimosis (occasionally)
The presence of the tumour will often become apparent only when the penis is extruded from the prepuce
Tumours of the penis - tx
Phallectomy
TVT:
- can be treated either using chemo or radiotherapy
- mets, although reported, is considered unusual
- prognosis is excellent in the majority of individuals
Mammary tumours - prevalence
- common in female dogs, rare in male dogs and cats
- more common in female dogs that are either not neutered or were neutered after 2y/o
— risk of dog developing a mammary tumour is 0.05% if neutered before their 1st heat (approx 6m/o), 8% after their 1st heat, and 26% after their 2nd heat, with no effect if neutered after 3rd season - cats spayed before 6m/o have a 7x reduced risk of developing mammary cancer
- neutering before 1st oestrus reduces lifetime risk by 91% in cats
- neutering at any age reduces the risk of mammary tumours by 40-60% in cats
- more than 1/4 of entire female dogs will develop a mammary tumour during their lifetime
- in female dogs, 50% of mammary tumours are benign, 50% are malignant
- however, few of the malignant mammary tumours are fatal
- in contrast, over 85-90% of mammary tumours in cats are malignant and most of these have an aggressive biologic behaviour (i.e. mammary tumours in cats tend to be locally invasive and spread elsewhere in the body)
Mammary tumours - signalment
- poodles, dachshunds and spaniels most affected
- siamese and other oriental breeds, and DSH are most affected
- in dogs, obesity at a young age is a risk factor
Mammary tumours - CS
Palpable mass underneath the skin of the abdomen or near a nipple is the most common finding in dogs and cats.
Other signs and symptoms include:
- discharge from a mammary gland
- ulceration of the skin over a gland
- painful, swollen breasts
- loss of appetite
- weight loss
- generalised weakness
Mammary tumours - diagnosis
Good general CE needed to find location, size and character of all mammary masses and access local LN enlargement
Other procedures are performed to stage the cancer (determine what type it is and where it is located in the body):
- full haem&biochem, urinalysis ± clotting profile
- abdo US, chest rads / CT scans (used to check for mets)
- FNA & cytology: LN may also be assessed to look for spread
- biopsy may be indicated to rule out an inflammatory mammary carcinoma (sx is generally not indicated for this tumour type)
Inflammatory mammary carcinoma - tx
- sx is not recommended for dogs with inflammatory mammary carcinoma as it doesn’t improve survival rate
- an effective tx has not been discovered
- radiation therapy in combination with NSAIDs has been shown to provide the most effective analgesia in dogs, but the prognosis remains poor
Mammary tumours - surgery
- the type depends on the size, location and number of mammary tumours and species
- in general, sx is more conservative for dogs with mammary tumours and involved removal of either the mass alone of the affected mammary gland
- however, in cats more aggressive sx is recommended with removal or 1 or preferably both sets of mammary glands
- sx to remove both sets of mammary glands from a cat is often performed in 2 surgical procedures 2-3w apart
- the local LN should also be removed in cats, if possible, to assess for evidence of spread of the cancer
- the role of neutering female dogs with mammary tumours is controversial. most studies have shown no beneficial effect of neutering at the time of tumour removal in preventing the development of new mammary tumours, or influencing the aggressiveness or mets potential of existing mammary tumours
- the role of chemo in cats and dogs with malignant mammary tumours has not been clearly defined for all tumour types
- for most mammary tumours in cats and dogs, hormonal therapy, immunotherapy and radiation therapy either have not been investigated or are not beneficial
