T/F: Oral tumors are more common in dogs than cats, and more common in males than females.
True
What are the “Big 3” DDx for oral tumors in dogs? What are the “Big 2” for cats?
Dogs: Melanoma, SCC, Fibrosarcoma (in order of most to least common)
Cats: SCC, Fibrosarcoma
What type of biopsy is indicated for a proliferative oral tumor? Non-proliferative oral tumor?
Proliferative - Incisional “shave” biopsy (under heavy sedation)
Non-proliferative- Incisional biopsy never through lip and NOT under sedation
DO NOT DO EXCISIONAL BIOPSY
What is the most important prognostic/staging indicator for oral tumors?
Size
What special stain can be used to differentiate a sarcoma from an amelanotic melanoma?
Melan A
Thorough staging is required for oral tumors, especially malignant melanoma. What needs to be done do stage these?
Abdominal US
Full body CT
A 1.5 year old golden retreiver presents with a very large benign loooking oral tumor. The biospy comes back as a fibroma. Thoughts?
Probably not a fibroma, but a fibrosarcoma
Aggressive surgery required
T/F: Oral fibrosarcomas and SCC have low metastatic rates but are locally invasive.
True
Why are significant bone resorption and hypercalcemia common PNS in cats with oral SCC?
Tumors tend to express PTH-rp
What is the predilication site for oral SCC in cats?
Sublingual
What is the feline counterpart for acanthomatous amelioblastomas? What is done to control these tumors?
Feline Inductive Odotogenic tumors
Aggressive local surgery
Why do more rostral oral tumors havea better prognosis?
Easier to excise
What is the benign slow growing oral tumor common in dofs that contains proliferative fibroblastic connective and odontogenic tisssue and how should you address it?
Peripheral odotogenic fibroma
Surgically excise mass, preferrably using cryo. Can wait and see if you have a confirmative biopsy.
What can be done to shrink oral melanomas?
Radiation therapy
What drug should be given to all cats with oral SCC?
Piroxicam (prolongs survival)
What parasite causes esophageal tumors and what kind of tumor forms?
Spirocerca lupi
Sarcomas
What is the most common esophageal tumor? Where do they tend to form in cats and which sex is prediposed?
What is the other most likely DDx?
SCC
Middle 1/3 of esophagus just caudal to thoracic inlet, females prediposed (cats)
DDx: Leiomyosarcoma
What is the gold standard for diagnosing esophageal tumors?
Biopsy via esophagoscopy
What breeds are prediposed to gastric tumors? Sex prediliction?
Belgian Shepherds
Chow chows
Males >> Females
What is the most common clinical sign with gastric tumors?
Anorexia
What are the “Big 2” Ddx for gastric tumors in dogs? What is the most common gastric tumor in cats?
Dogs: ACA (adenocarcinoma), Leiomyosarcoma
Cats: LSA
Where do gastric adenocarcinomas tend to form? What do they look like?
Pyloric antrum/lesser curvature
Often scirrhous (firm, white or serosal surface), Linitis plastica (leather bottle)
What is the staging test of choice for gastric tumors? What is the best tool for assessing resectability?
Ultrasound (US-guided FNA/cytology)
Endoscopy
Which gastric tumor has a better prognosis, ACA or leiomyosarcoma?
Leiomyosarcoma (MST 12-21 mo)
(ASA most dead within 6mo)
Species: Large intestinal tumrs are more common than small intestinal tumors in ____ while the opposite is true in ____.
Dogs
Cats
What are the “Big 3” DDx for intestinal tumors in dogs? Cats?
Dogs: LSA, ACA, Leiomyosarcoma
Cats: LSA, ACA, MCT
Unlike other tumors, WHO staging for intestinal tumors depends on what rather than tumor size?
Depth of invasion
What are negative prognostic indicators for dogs with intestinal LSA? Cats?
Dogs: failure to achieve remission, diarrhea at initial presentation (MST 2 mo)
Cats: poor response to chemo (MST<3.5mo vs >11mo if do respond)
What is a negative prognostic indicator for dogs with ACA?
Being female (MST males 27days, females 28 days)
From what cells do gastrointestinal stromal tumors originate? What is their prediliction site?
Interstitial cells of Cajal
Cecum
____ is a receptacle for metastasis and receives mets 2.5x more frequently than developing primary tumors in dogs. In cats primary tumors of this organ are more common than mets.
Liver
What are the 4 general categories of primary liver tumors? What are these categories based on?
Hepatocellular
Bile duct
Neuroendocrine (carcinoid)
Mesenchymal
Based on cell of origin
What do you call a primary hepatobiliary tumor that is large, solitary and confined to a single liver tobe? What tumor type is most commonly of this morphology?
Massive
Hepatocellular
What is the morphologic descriptor for hepatocellular masses that are multifocal and involve all liver lobes? What tumor type is most commonly of this morphology?
Diffuse
Neuroendocrine
What staging modality is recommended for staging an assessing resectability for large or infiltrative hepatobiliary tumors?
CT
What is the most common liver tumor in dogs? Cats?
Dogs: HCC
Cats: Hepatocellular adenoma
What dictates the treatability of hepatocellular tumors?
Morphologic subtype
In division of the liver are complications of tumor removal most severe and why?
Right division
Vena cava runs through liver here
T/F: MST for dogs who have had surgery to remove a liver mass is significantly higher than for patients who did not undergo surgery.
True (>1460 days vs 270 days)
How much of the total mass of the liver can you remove and how long does it take for it to regain its original size?
75%
6 weeks
What tumor is common in cats and account for >50% of all feline hepatobiliary tumors?
Hepatobiliary cystadenoma
What is a risk factor for bile duct carcinomas in dogs and cats?
Trematode infestation
What is carcinomatosis and in what species does it occur?
Diffuse intraperitoneal mets from bile duct carcinomas
Cats
T/F: Chemotherapy and RT are not effective for bile duct carcinomas.
True
How are neuroendocrine tumors differentiated from carcinomas? Does this tumor occur in younger or older animals? Is it common?
Silver stains
Younger
No, rare
What is the non-invasive interventional radiologic technique used to isolate affected liver lobes microvascularly (i.e. stop blood supply)?
Chemoembolization
Why does chemotherapy not work well for liver tumors? How do you bypass the issues that make chemo ineffective?
Rapid development of drug resistance
Bypass by using chemoembolization
Why does radiation therapy not work well for liver tumors?
Liver cannot tolerate the high levels of radiation (>30 Gy) required to achieve remissions
Where is the preferential site of metastasis for renal tumors?
Lungs
What are the 4 general categories of primary renal tumors?
Renal tubular carcinomas
Transitional cell carcinomas
Nephrobastic tumors
Non-epithelial tumors (Sarcomas and LSA)
What PSA occurs in GSD with renal cystadenocarcinoma?
Nodular dermatofibrosis
Females get uterine leiomyomas
What is the gold standard for assessing and staging renal tumors?
Abdominal ultrasound + US guided FNA/cytology
Why do we tend to shy away from using excretory urography for renal tumors?
Contrast agents are nephrotoxic and could compromise the healthy kidney
Why would you want to use CT to work-up/stage a renal tumor?
To ensure the caudal vena cava is not being infltrated
What is the most common renal tumor in dogs? Is it usually uni- or bilateral? What is the most common PNS associated with this tumor?
Renal cell carcinoma
Unilateral
Polycythemia
Aside from the autosomal dominant cystadenocarcinomas that GSD get, what congenital tumor also affects young dogs? What is this tumor called in humans?
Nephroblastomas
Humans: Wilms’ tumor
What is the most common renal tumor in cats? Why is staging very important? Is it usually uni- or bilateral?
Lymphoma
Staging important because LSA is often multicentric
ALWAYS consider disease bilateral
How is renal lymphoma treated in cats
Multi-agent chemotherapy
(NEVER SURGERY)
What is the treatment for renal carcinoma in dogs?
Surgery (resistant to chemo, hormonal therapy and RT)
What symptoms accopany functional adrenocortical tumors originating in the zona glomerulosa?
Cushinoid symptoms
Where do pheochromocytomas originate? What do they produce?
Medulla of adrenal gland
Epi, norepi, dopamine
If a dog is asymptomatic and has an adrenal mass that is ____cm it is probably benign. Serial US should be done every ________ to monitor the mass and track its growth.
<2cm
3 months
What tests can you use to confirm functionality of an adrenocortical ACA or adenoma?
ACTH stim
U:C ratio
What test can you perform to confirm that an adrenocortical tumor is adrenal dependent?
Endogenous ACTH
What test can you use to diagnose a pheochromocytoma?
Metanephrine/Normetaneohrine to Creatinine ratio (urine test)
If you suspect that a tumor is a pheochromocytoma, what should you pre-treat the animal with before surgery? Why?
Phenoxybenzamine (q2-3 weeks)
To minimize the potential for surges in blood pressure during surgery
T/F: The prognosis is the same regardness of whether an adrenal tumor is an ACA or an adenoma.
True