Oral + Mammary tumours Flashcards
What are clinical signs of oral tumours?
- Mass / facial swelling
- Oral bleeding
- Dysphagia / pain
- Halitosis
- Epistaxis
- Loose teeth / proliferative lesions noted at dentals (always biopsy)
- Cervical lymphadenopathy
What are the most common oral tumours in dogs?
- Malignant melanoma
- Squamous cell carcinoma
- Fibrosarcoma
- (Acanthomatous ameloblastoma + peripheral odotogenic fibroma)
How are oral tumours diagnosed / staged?
- Assessment under GA
- Dx = Biopsy (incisional wedge), FNA
- Staging = assessment of local LNs, thoracic imaging + abdominal imaging (for melanoma)
For all malignant tumours:
* FNA submandibular nodes
* Image retropharyngeal nodes and sample if possible
* If CT available consider lymphangiography
How are primary oral tumours managed?
- Surgery - maxillectomy / mandibulectomy, (margins by histology) - cats may need feeding tube for months post-op
- For FSA, SCC surgery followed by adjuvant RT
- palliative RT alone when surgical excision impossible
What are complications of oral surgery?
- Recurrence
- Dogs adapt well, cats = variable
- Bleeding
- Infection
- Altered cosmetic appearance
- Difficulty prehending food / messy eating
- Salivation
- Mandibular drift
What is melanoma? What does it effect? Dx?
- Smaller old dogs = mean 11.4yrs, golden retriever, cocker spaniel, miniature poodle, chowchow
- Very locally invasive
- High metastatic rate
- Dx= melanin containing mesenchymal cells
Tx of primary melanoma?
- Surgery - associated w high rates of local recurrence
- 35% 1yr survival
- Size significant for survival time
- Radiation therapy - usually 5 months till recurrence
- Anti-metastatic treatment = Plasmid vaccine immunotherapy - used in stage II + III, (20%) success, EXPENSIVE
How are oral SCC treated?
- Low metastatic rate - local control = mainstay of therapy
- Surgery = mandible (10% recurrence), Maxilla (30%), MST 19-26months
- RT = MST 15 months
- Surgery + RT = MST 34months
- If other therapies impossible = medical = Piroxicam + carboplatin
What is presentation of tonsillar SCC? Tx? Prognosis?
- Dysphagia, coughing
- Enlarged cervical lymph nodes = abcessation
- FNA yields necrotic debris and sometimes tumour cells
- Oral examination reveals enlargement of 1 or both tonsils
- Metastatic rate >70%
- Tx =
- Local control of tonsillar enlargement - surgery or RT
- Surgery or RT for lymph node metastasis
- Carboplatin or mitoxantrone chemotherapy might be beneficial
- Prognosis - MST 7 mths
– Patients who receive the most therapy live longest
– Control of local/regional disease most important
What dogs are predisposed to fibrosarcomas? how invasive / metastatic are they
- Golden retrievers, Labradors
- Invasive
- Low / moderate metastatic risk
What is Tx of fibrosarcomas?
- Local control mainstay of therapy but challenging
- Surgery single most important therapy =
- Margins 3-5cm+
- But recurrence rate is 40 – 60 %
- MST 1 yr after surgery
- Multimodal therapy often best =
- Surgery and RT - MST 18 – 26 months
- Recurrence rate ~ 30 %
- RT alone = MST – 7 months
- Smaller tumours = better outcomes
- T1 tumours – MST 31 months
- T2 and T3 tumours (> 2 cm) – MST 7 months
What are epulides?
*Non-metastatic lesions arising from gingiva
* Acanthomatous ameloblastoma
* Aggressive local behaviour and bone invasion
* Peripheral ondotogenic fibroma
* Slow growing firm masses usually not invasive
What is canine oral osteosarcoma?
- Not as rapidly metastatic as appendicular
– many tumours metastasise - Site and histological grade is prognostic
- Survival – mandibular > maxillary
- 14 – 18 mths vs 5 – 10 mths
- Complete excision vital: local recurrence >80%
- Most dogs with maxillary tumours die of recurrence
- Most dogs with mandibular tumours die of metastases
What are uncommon oral tumour of the dog?
– MCT
– Haemangiosarcoma
* Extramedullary Oral Plasmacytoma - Stage to rule out multiple myeloma
* Oral lymphoma: a form of epitheliotrophic - Generally require multi-agent chemotherapy, Some dogs with oral (only) epitheliotrophic lymphoma can do well with RT alone
* Undifferentiated tumour of young dogs - Rare – grave prognosis
What is the most common feline oral tumour? risk factors? signs?
SCC - locally invasive, low metastatic risk
* use of flea collars
* exposure to smoking
* canned food including canned tuna
- Can cause discomfort = anorexia
Tx of SCC in cats + outcome?
- Outcome depends upon surgical options
– Cats with surgically resectable disease can have a good outcome but recurrence is common
– Best outcomes in rostral mandibular SCC
– Soft tissue lesions affecting the tongue have a poor prognosis as resections are difficult - Long term feeding tube often needed for several months
- RT occasionally helpful
- Electrochemotherapy is an emerging therapy
What is feline fibrosarcoma? Tx?
- Usually middle aged or older
- Very locally invasive
- Main treatment is surgery – Good outcomes possible with
mandibulectomy (Maxillectomy more difficult)
What are other oral lesions to be aware of?
- Multilobular osteochondrosarcoma – dogs
-Popcorn appearance - radiographically - Viral papillomatosis - immunosuppressed dogs
-Wart like lesions affecting oral soft tissues - Eosinophilic granuloma - dogs (Husky and CKCS)
- Eosinophilic granuloma – cats
-Typically erosive lesions affecting upper lip near midline - Transmissible venereal tumour – dogs (vincristine!)
-Proliferative lesion affecting dogs who have been licking
What are risk factors for mammary tumours?
- Neutering =
- Neutering prior to first oestrus – 0.5 % life time risk
- Neutering prior to second oestrus – 8 % risk
- Neutering prior to third oestrus – 26 % risk
- No risk reduction if neutering after the second season
- Oestrogen / progestin use increase risk
- Obesity
- Age
- Breed- siamese, poodles, chiahuahua, dachshund, maltese
What is approach to mammary tumours?
- Mammary mass
- > 70% have more than 1 tumour
- Examine other glands carefully
- About 50% of canine MG tumours are benign
- FNA can be useful to exclude other ddx
- e.g. mastitis, lipoma or mast cell tumour, hyperplasia
- Excisional biopsy by single or segmental mastectomy reasonable for single lesions without negative prognostic indicators
- E.g. small, non fixed lesions
- Staging prior to treatment of suspicious lesions
What is pre-surgical assessment of canine mammary tumours?
- Clinical Examination =
- Tumours > 3 cm have poorer outcome
- Fixed tumours
- Palpably enlarged lymph nodes
- Local staging =
- Assessment of local lymph nodes
- Consider typical drainage patterns - Not absolute so assess all nodes
- Distant staging = Thoracic Xray, CT, US
What is surgery of canine mammary tumours?
- Low risk - single mastectomy
- High risk / intact bitch – consider regional mastectomy
- Intact bitches =
- 55% develop a new tumour on the ipsilateral side hence consider unilateral chain mastectomy
- Likely hormone field effect therefore consider bilateral resection in young intact bitches with multiple tumours
- Excision margins
- For mobile lesions – whole gland removal enough
- Fixed lesions – need 2 cm margins and removal of affected abdominal fascia / wall
What are post surgical prognostic factors?
- Tumour type =
- Benign versus malignant
- Less tissue heterogeneity associated with a poorer outcome (complex vs simple)
- Sarcoma especially osteosarcoma – poorer than carcinoma
- Possible prognostic factors
- Poor standardisation of data makes it difficult to determine the independent significance of tumour types
- Mitotic rate / Ki-67
- Grade
- Hormone receptor expression
What is canine inflammatory carcinoma? Tx? Prognosis?
- Tumours extremely painful
- Easily mistaken for mastitis
- Generally all gland affected
- FNA yields inflammatory cells and tumour cells
- Excision not typically feasible - Recurrence very common
- Prognosis = Generally very poor
- Treatment is palliative
- Medical therapy might prolong survival – few months
What is feline mammary tumours?
- Similar risk factors to dogs
- 85 – 95 % of feline mammary tumours are malignant
- Clinical presentation =
- > 60% have more than 1 tumour at diagnosis
- Hormone receptor expression frequencies are lower
- A significant differential is fibroepithelial hyperplasia - Usually all glands are enlarged
What are prognostic factors of feline mammary tumours?
- Tumour size =
- > 2 cm – MST 6 months
- < 2 cm – MST > 3 years
- Lymph node metastasis =
- Lymphatic drainage less predictable than dog
- Assess inguinal and axillary nodes bilaterally
- Distant metastasis
- Breed - DSH have better outcome
What is surgery of feline mammary tumours?
- Chain mastectomy preferred to single or regional mastectomy =
- Unilateral when lesions on one side
- Stage bilateral when lesions bilateral
- Surgical resection of inguinal and / or axillary lymph nodes for high risk tumours recommended
Why would you perform ovariectomy in dogs at time of mammary tumour excision?
- Halves chance of new mammary tumour for benign mammary tumours
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