oncology exam 2 Flashcards
What is the #1 oral tumor in dogs, other 2 MC oral tumors?
1= MELANOMA
#2= SCC #3= fibrosarcoma
What is the #1 oral tumor in cats, other MC oral tumor?
1-SCC!!!
2- fibrosarcoma
Is an odontogenic tumor malignant or benign?
benign
What type of biopsy is preferred for proliferative oral tumors?
shave biopsy
True or false- to save time you should just biopsy an oral mass through the lip?
NO- WHY IN THE ACTUAL FUCK WOULD YOU DO THIS?
True or false- you should take two thoracic rads to check for mets from oral tumors?
false- take 3
Which of the following is false about malignant oral melanomas?
A. the non-pigmented variant is amelanotic melanoma and you can do special stains for Melan A
B. these tumors are malignant, but don’t generally result in mets
C. surgery results in local control
D. thorough staging is required
B- these tumors are malignant but they can form systemic mets in about 80% of animals, biggest point of treatment failure
True/false- oral fibrosarcomas are histologically low grade, therefore we don’t really need to worry about them?
Falsomundo- they are histologically low grade but they can be biologically high grade
-if biopsy comes back as fibroma don’t believe it
this type of tumor generally effects younger (7-8 yr) goldens and labs, and has relatively low met rate, BUT recurrent disease after surgery tends to be the biggest point of treatment failure
Tell me about oral SCC in dogs…
- locally invasive
- low rate of metastasis (<20%)
Where do oral SCC prefer to live in cats?
-sublingual site
these are locally invasive
risk factors= flea collar usage, smoke exposure, excessive canned food (esp tuna)
-increased PTHrp which can lead to bone resorption and hypercalcemia
Which type of odontogenic tumor is locally invasive into bone and needs very aggressive local surgery for control?
-ancanthomatous ameloblastoma- sheepdogs are overrepressented, rostral mandible is most common
Which is pretty much the feline equivalent of an ameloblastoma?
feline inductive odontogenic tumor
- locally invasive, no
metastasis
-tx like ameloblastoma
What is the gold standard treatment for oral tumors?
- aggressive surgical excision- almost always bone involvement (except peripheral odontogenic fibromas)
- need to have 2 cm margins for most
- more rostral= easier to excise, better px
Which types of oral tumors are responsive to radiation?
MELANOMA, SCC (dogs), acanthomatous ameloblastoma. and FSA
When would you consider chemotherapy for oral tumors?
- if tumor considered highly metastatic
- piroxicam- sublingual SCC in cats
- MELANOMA= NOT CHEMO RESPONSIVE
What is the MC gastric tumor in dogs? Second MC?
1- adenocarcinoma
2-leiomyosarcoma/leiomyoma
MC gastric tumor in cats?
lymphoma
What is the predilection site for gastric ACA?
- pyloric antrum/ lesser curvature
- HAS A HIGH METASTATIC RATE- 75%
What diagnostic modalities are preferred for gastric tumors?
- abdominal ultrasound
- U.S. guided FNA/cytology
- endoscopy- assess resectability
Recommended treatment for gastric tumors?
-surgical excision
Which of the following has the worst prognosis?
Leiomyosarcoma, LSA, ACA
ACA- most dead within 6 months, can have better px if no mets and resectable
LSA- doesn’t respond well to chemo, can resect
Leiomyosarcoma- MST- 12-21 mo, metastasis- not poor px factor
px depends on surgical excision, tumor type/grade, presence of mets
Which animal is more susceptible to large intestinal tumors? small intestinal tumors?
- LI tumors= dogs- collie and GSD, male sex predilection
- SI- cats
How do we diagnose intestinal tumors?
- US guided FNA/cytology- relatively high diagnostic accuracy- should attempt in all cases
- endoscopy can be used but will not provide access to jejunum and proximal ileum- careful in cats because MC location is ileum
- goal is to rule out LSA
What is the top ddx for intestinal tumors in dogs and cats?
LSA!
ACA is the second most common in both
third most common in dogs: leiomyosarcoma
third most common in cats: MCT
Treatment for intestinal tumors
-surgery- exception is LSA because it’s usually too diffuse
- take wide margins (4-8 cm)
- mesenteric and regional lymph nodes should be assessed, resected, and aspirated (if not amenable to excision)
MST for intestinal LSA
- dogs- 77 d, negative prognostic indicators= didn’t achieve remission or diarrhea at presentation
- cats- MST- 201-280 days, px indicator= response to chemo/tx
MST- intestinal ACA
- dogs- MST= 272-300 days, female= worse px
- cats- majority are advanced with 72% metastatic rate at dx
- MST= 5-15 mo
intestinal MCT- prognostic factors
- dogs= VERY BAD, 16 day MST
- cats= solitary intestinal MCT without mets may have prolonged survival following complete surgical excision
intestinal MCT- leiomyosarcoma
-dogs: 8 months after surgical resection
Gastrointestinal stromal tumor
- express c-kit on IHC
- predilection for cecum
- MST= 11.6 months, if survive sx= 37.4 months
- many die due to septic peritonitis because masses rupture before diagnosis
Most common chest wall tumors in dogs (in order of prevalance)
- OSA, CSA
Treatment of chest wall tumors
- en bloc excision with chest wall reconstruction (max rib excision=6)
- can do prosthetic mesh augmentation depending on size and location of defect
- adjunctive chemotherapy recommended for OSA
prognosis for chest wall tumors
-MST= 120 days for OSA following chest resection alone
MST- 240 days OSA - chest wall resection and chemo
MST= 299-1080 days with CSA
-tumor type and complete histologic resection play role
Which syndrome is unique to cats with lung tumors?
- lung-digit syndrome= LAMENESS
- mets to toes–> weight bearing digits and third phalynx
- always do chest rads when you see this
Most common lung tumors in dogs
carcinomas
- bronchoalveolar ACA= MC
- SCC= uncommon
-others= histiocytic sarcoma (often multiple pulmonary masses)
most common lung tumors- cats
-bronchial adenocarcinoma
What is the best diagnostic tool for lung tumors in both dogs and cats?
-transthoracic FNA/cytology
What is a major negative prognostic factor for lung tumors?
-tracheobronchial lymph node enlargement
Treatment of lung tumors
- lateral thoracotomy for small to medium lung tumors–> hilar ln biopsy (even if small on ct)
- partial lobectomy= okay, complete=preferred
Lung tumor prognostic factors- dog
- tumor size= small <5 cm
- location= more peripheral is better
- clinical signs at time of diagnosis- 240 days with c.s.- 545 without
- clinical stage- T1 (solitary)- 26 months, T2= multiple (7 months), T3- invasion into adjacent tissue (3 mo)
- histiologic score- 790 days if well differentiated, 25 days if moderately differentiated, 5 days if poorly differentiated
- 1 month with lymph node involvement vs 15 mo
- MST= 8 m with SCC, 19 mo with ACA
lung tumor prognostic factors- cat
- histiologic grade= most important
- poorly differentiated- MST=2.5 m
- well differentiated- MST= 23 months
- presence of pleural effusion= negative
What is a common concurrent condition with thymoma?
- Paraneoplastic syndrome- 67% thymomas
- myasthenia gravis
- erythema multiforme
- hypercalcemia
- T-cell lymphocytosis
- anemia
- polymyositis
Most common cranial mediastinal tumor
-lymphosarcoma- thymoma is second
Diagnosis of thymoma
- may have mass effect on thoracic rads
- FNA/cytology- large numbers of mature lymphocytes
- send out flow cytometry
Treatment of thymoma
- surgical treatment= gold standard
- radiation if not amenable to surgery
- chemo is usually ineffective
thymoma- prognosis for dogs
- good overall
- surgical excision- MST= 790 days
- radiation- MST= 248 days
- poor prognostic factors: younger, megaesophagus, lymphocyte rich variants= better
thymoma- prognosis for cats
- excellent overall
- sx excision, MST= 1,825 days
- radiation= MST= 720 days
What is the most common primary bone tumor of dogs and cats?
OSTEOSARCOMA
- 85% bone tumors in dogs
-second MC= chondrosarcoma
Signalment of OSA in dogs
- large to giant breed dogs- size and height prognostic
- early gonadectomized Rotties (<1 yr)
- breeds MC= great danes, irish wolfhounds, greyhounds, rotties, scottish deerhounds, St. bernards
proposed etx of osteosarcoma
- hormonal
- genetic
- repetitive microtrauma
- molecular factors- protooncogenes- MET, Tropomyosin-related kinase, HER 2
- insulin like GF
- telomerase
How can you differentiate osteosarcoma from infectious causes of lameness like “valley fever”
-if infectious usually systemically ill
Where is the predilection site for osteosarcomas? Dogs and cats?
- appendicular skeleton
- dogs: forelimbs 2x more than pelvic limb, distal radius and then proximal humerus are MC sites, favor metaphyseal region
- cats- pelvic limb, favor diaphysis
True/False OSA are known for crossing the joints?
False
What is the preferred diagnostic modality for OSA?
- FNA/cytology
- can do biopsy but it’s then difficult to do limb sparing procedure
-biopsy needles- Jam Shedi, Michele trephine- higher risk of pathological fracture
What is the gold standard for local management of primary bone tumors?
-limb amputation
Your dog is extremely obese making him a poor candidate for amputation, his tumor is located on the humerus, does this make him a better or worse candidate for limb salvage?
-worse- distal radius is the preferred site for limb salvage procedure
True/False- the complication rate is high for limb salvage procedures, therefore you really shouldn’t even attempt them
- true and falseish
- the complication rate IS high >50%, however it’s important to use appropriate case selection
- if the procedure goes well there is anticipated to be good to excellent function of leg in 80% of dogs
-if there is infection, as in 50% of cases this decreases the MST from 685 days to 289 days :(
What is the most severe complication of stereotactic radiosurgery?
- fracture of radiated bone in 36% of patients
- proximal humerus may be a better location for SRS, lower fracture rate
So you remove the limb with OSA, that means you removed the problem! Case closed, happy three legged doggo goes home and lives a long life! FALSE, why is this wrong?
With local control only, most die of metastasis within 6 months.
adjunctive chemotherapy with carboplatin or platinum containing protocol is recommended in all cases.
What is the major effect of biphosphonates?
-inhibits osteoclastic bone reabsorption
Aminobisphosphonates are associated with the potential for renal toxicity and jaw osteonecrosis, why do we use them?
-pain palliation in 30-50% dogs
When is pulmonary metastectomy indicated in OSA patients?
- if development is more than 300 days after initial diagnosis
- less than 3 radiographically evident mets
- no doubling in size/development of lesions in 4 week period
- palliative relief for hypertrophic osteopathy
What is the preliminary vaccine caused that was shown to prolong MST from 423 days to 956 days?
Aratana
Prognosis for OSA
- palliative- analgesia: MST=1-3 mo
- palliative-RT- 4 months
- sx with curative intent or SRT alone= 4-6 months
- sx or SRS and chemo= 8-12 months
Negative prognostic factors with OSA
-body weight- the bigger the worse
-age: <7 yrs or >10 yrs
-tumor volume- large is bad
-histiologic grade
-ALP higher= worse
tumor site: proximal humerus= worse
What is the most common cutaneous tumor in dogs and the second most common cutaneous tumor in cats?
MAST CELL TUMORRRRR
What breeds of doggos and cattos are predisposed to MCTs?
- dogs- the B’s!- boxer, bull terrier, boston terrier, bulldog–> lower grades and less aggressive
- labs and mixes can also get it
- Siamese cats predisposed
Location of MCTs
- dogs (in order of prevalence): trunk, extremities, head, neck, tend to be SOLITARY
- cats: head and neck- may have more than one on presentation
What bioactive substances do MCTs produce?
- vasoactive substances- histamines, prostaglandin’s
- heparin-proteoglycan matrix*
- chemotactic factors
- proteolytic enzymes*
- serotonins
What is Darier’s sign?
-degranulation of mast cells with erythema, swelling and if severe anaphylaxi and hypotension
What effect do degranulating mast cells potential have on the GI?
- histamine stimulates gastric acid secretion
- 35-83% of dogs with MCT will have some evidence of GI ulceration at necropsy or endoscopy, may have perforated ulcer
- if dog has adequate tumor control= normal plasma histamine content
Effects of degranulation of MCT on surgery
- delayed wound healing due to proteolytic enzymes and vasoactive amines
- hypotension
- local hemorrhage due to release of heparin
- may have surgical dehiscence if incomplete excision
What tests do you do if there are no negative prognostic factors and your MCT is amenable to wide excisions?
-only need to do MDB and regional LN aspirate
Why do we do a thoracic met evaluation of MCT don’t met to lungs?
-intrathoracic lymph node enlargement
What is the most common form of MCT tumor in cats?
- MC- mastocytic- compact- has better px
- young Siamese cats can have histiocytic form which can spontaneously regress over 4-24 months
Which is the most common histological grade of MCT in dogs by the Patnaik 3 tier system?
-grade II
When is complete excision alone enough treatment for a MCT?
-when it’s low grade and localized
When should you do adjunctive chemo in a localized MCT?
-if it’s high grade but there is a complete excision
If the MCT is localized but non-resectable what do you?
-chemo to downstage then surgery
What do you do if the planned curative excision of the MCT, but it’s unsuccessful?
-scar revision is your best bet
T/F you have a higher grade variant MCT, surveillance is completely okay?
- false fam
- 23% incompletely excised grade II tumor recurred
If you have disseminated disease with a local MCT what is the best treatment?
-start with chemo, measure response, once maximum local response determined consider local excision/RT of primary tumor if patient doing well
What chemotherapy protocol is indicated in high risk dogs with MCTs>
-prednisolone/vinblastine
Palladia (TKI)
- has biologic activity in 60% dogs with mutation in c-kit gene
- renders KIT protein constitutively active
- can test for c-kit mutation with MCT prognostic panel
Patient related MCT prognostic factors
- breed- less aggressive in boxers and brachycephalics
- systemic signs- usually with higher stage disease
- location: bad= oral and other mucous membranes, preputial and scrotal, visceral or BM
- sub cutaneous may do better
Tumor related MCT prognostic factors
- size- if greater than 5 cm shorter MST
- c-kit mutation= worse prognosis
- proliferation rate
- microvessel density
- recurrence
- histiological grade- well-differentiated usually treated with local control
- Kiupel high-grade MCT- shorter time to metastasis or new tumor development
Do multiple MCT automatically indicate a negative prognosis?
-No! studies show outcome is similar to single MCT’s if adequate treatment is initiated for each new mass
When to consider mast cell tumor prognostic panel
- marginally or incompletely excised low grade MCT
- high grade MCT’s or cases of confirmed metastasis when chemotherapy is planned- to confirm likelihood patient will respond to TKI
What is the benefit of prednisone in MCTs?
- pre-op prednisone may shrink the diameter of the tumor
- pred/vinblastine given to high risk dogs–> MST= 3.8 yrs
So your owner declines conventional treatment for their doggo with MCT, what type of chemotherapy can you offer?
- about 1 mg of trimcinolone/cm tumor
- slows progression- median time= 63 days
What is the most common malignant canine bladder tumor? MC non-neoplastic dx?
- Transitional cell carcinoma= MC
- other Ddx: SCC, ACA/carcinoma, Rhabdomyosarcoma, Fibroma, Mesenchymal
- non-neoplastic- polypoid cystitis
What can cause bladder neoplasia?
- topical insecticide and herbicide exposure- glycophosphate
- obesity- overweight females 28x more likely
- breed: SCOTTIE
What are some ways to decrease the risk for bladder cancer
- use newer spot-on type flea medications (i.e. with fipronil)
- limit exposure to lawn chemicals and older flea/tick products
- feed veggies 3x a week
Most common location of TCC
-trigone of bladder
C.S. of TCC
- hematuria, dysuria, PU
- lameness–> bone mets
On a rectal exam, what may be noted with TCC
-thickened urethra/iliac ln
How to diagnose TCC
- traumatic catheterization is preferred
- cystosonogrophy
- cystoscopy with biopsy–> assess for resectability
- BRAF mutation on detection assay- can be used as a screening tool in at risk breeds
What does the field effect refer to?
-entire bladder may undergo malignant change in response to carcinogens in the urine
How to surgically treat TCC
- invasive- bladder surgery- partial or complete cystectomy, laser ablation- MST=299 d
- less invasive: cystotomy tube, transurethral stenting
When a partial or complete cystectomy is indicated
-generally for solitary masses in apex of bladder without regional or systemic metastasis
Non-trigonal bladder neoplasia
-can do full thickness and daily piroxicam- may have improved outcome
Palliative stenting- MST
- ranges up to 536 days
- treatment with NSAIDS before and chemotherapeutics after–> increased MST to 251 days
NSAID therapy for TCC
- COX-2 expressed in epithelial malignancies
- piroxicam aka feldane
- all dogs with TCC should receive NSAIDs if possible- dosage= 0.3 mg/kg PO q 24 hrs
Chemotherapy for TCC
- only palliative
- mitoxantrone with piroxicam- MST= 291 days (8 months)
- metronomic chemotherapy- MST= 221 days
MST- RT and chemo for TCC
- 326 days (about 4 months)
- survival rate not superior to mitoxantrone and piroxicam without RT
Feline bladder neoplasia
- rare but TCC most common
- MST= about 9 months
Which dog breeds are predisposed to mammary gland tumors?
-pointers, Irish setter, spaniels, Great Pyr, Airedale, mini/toy poodles, Dauchshund, Keeshond
Which cats are predisosed to mammary gland tumors?
-siamese and domestic short hairs
Where is the most common location of mammary gland neoplasia in dogs>
-glands 4 & 5- greater volume of mammary tissue
What percentage of canine mammary gland tumors are benign vs malignant?
- 50:50
- benign: hyperplasia, dysplasia, adenoma
- malignant variants: carcinomas, sarcomas
What percentage of mammary gland tumors are malignant in cats?
- 85-95%
- carcinomas major ddx
In queens, what is OHE effect on mammary tumors?
- decreases risk 40-60%
- before 6 months= 91% risk reduction
- between 7-12 months- 86% risk reduction
- 13-24 months: 11% risk reduction
Which dog is more predisposed to mammary tumor: fat small breed dog, or skinny large breed dog?
-fat small breed, underweight during puberty is protective and small breeds more prone
After 4 years old, an OHE does not decrease the risk of mammary cancer, what is the risk prior to 1st, 2nd, and 3rd estrus?
- OHE prior to 1st estrus= .5% lifetime risk
- OHE prior to 2nd estrus= 8% risk
- OHE prior to 3rd estrus= 26%
True/false- FNA/cytology is a good diagnostic test-
false- lots of false negatives but good to rule out inflammatory carcinomas and metastatic mammary tumors
-if negative and you suspect mammary tumor- biopsy- excisional in dog, incisional in cat
In which animal would you perform a single session bilateral radical masectomy with excision of axillary and inguinal lymph nodes?
- cats!
- dogs with single tumor- simple lumpectomy/mastectomy
- dogs with multiple tumors- regional mastectomy, staged bilateral mastectomy
Chemotherapy for mammary gland tumors in cats
-tumors
When is adjunctive chemotherapy recommended for cats with mammary tumors?
- tumors >3 cm with or without lymph node involvement
- MST= 15 mo
What are the major ddx for canine vaginal tumors?
- most vaginal tumors are benign and smooth muscle origin- Leiomyoma
- malignant dx: leiomyosarcoma
Top differentials for canine testicular tumors?
- intestinal cell tumor
- seminoma
- sertoli cell tumor
Which of the following is false about soft tissue sarcomas?
A. most are solitary
B. more common in middle aged to older large breed dogs
C. Rhabdomyosarcomas tend to develop in older dogs
D. they have high local recurrence rate after conservative excision
C. Rhabdomyosarcomas tend to develop in YOUNGER dogs
What is the route of metastasis for STS?
- hematogenous route of metastasis
- regional LN metastasis is uncommon except in synovial cell
What does the 10,20,30 rule mean?
- grade of STS is predictive of metastasis and local recurrence
- 1,2,3–> 10%, 20%, 30%
Do smaller or larger STS tend to not respond to chemotherapy or RT?
-larger >5 cm
How to diagnose STS>
- FNA- sarcoma do an incisional biopsy (tru cut or wedge)
- do thoracic rads (met check and/or US/CT/MRI
What are the margins for removing a STS?
- wide excision (3 cm radial & 1 fascial plane or two muscle planes deep)
- radical surgery may be required
- 1st sx is best chance
Prognosis for STS
- negative prognostic factors for local control: large tumor size, incomplete surgical margins, high histological grade
- recurrence rate= 28%
- MST about 4 yrs with surgery alone
What is it in vaccines that is suspected to be a cause of feline injection site sarcomas?
-aluminum adjuvant
What type of biopsy should you not do for FISS
- EXCISIONAL- do incisional
- tumors are very infiltrative, may need a CT for surgical margin planning
Current recommendation for feline ISS treatment?
- surgical excision with 5 cm radial margins, 2 muscle planes deep
- have 14% recurrence rate
- local recurrence- 26-59%
In which animal are hepatobiliary tumors more commonly primary? more commonly mets?
- More commonly primary in cats
- more commonly mets in dogs, dogs more often malignant
What are the four primary hepatobiliary tumors?
- hepatocellular
- bile duct
- neuroendocrine (carcinoid)
- mesenchymal
- LSA most common in cats but not considered primary tumor
Massive hepatobiliary tumor
- confined to single lobe, easiest to treat surgically
- hepatocellular carcinomas
Nodular hepatobiliary tumor
-multifocal, one or several lobes
diffuse hepatobiliary tumor
- multifocal or coalescing nodules involving all liver lobes or diffuse effacement of parenchyma
- neuroendocrine is most common
Complaint and signalment for hepatobiliary tumors
- majority may be asymptomatic at dx, may be found when looking for cause of increased liver enzyme
- C.S.- anorexia, wt loss, vomiting, PU/PD, ascites
What is the most common primary hepatobiliary tumors in dogs? cats?
- Hepatocellular- most common primary liver tumor in dogs
- hepatocellular adenoma is more common than HCC in cats
What dictates the treatability of hepatocellular tumors?
-morphological subtype
Bile duct associated neoplasia
- bile duct adenoma (benign)
- bile duct carcinoma (malignant)
- hepatobiliary cystadenoma= common in cats!!! can have long term survival rate with benign neglect
Carcinomatosis
- cats
- chemotherapy and RT NOT effective!
