Lecture 5 Flashcards
What is the definition of canine lipoma
A benign subcutaneous mass with a soft texture usually localized.
Who does canine lipoma affect
Most commonly dogs, rare in cats and horses
Breed predispositions
Hypothyroid dogs
What are the clinical signs of canine lipoma
Palpation of small, soft mass under the skin
Should not cause discomfort to the patient
Usually around abdominal region but can be anywhere
Tendency to develop multiple
How do you diagnose canine lipoma
Fine needle aspiration
Surgical removal and histopathology
How do you treat canine lipoma
Surgical removal can be done but it is not necessary unless it is restricting movement
Describe basal cell tumor
Has many specific names
Mid to old dog and cat
Mostly on head and neck
Describe follicular tumor
Often inflammation
Older dogs
Can sometimes squeeze out material
Describe sebaceous adenoma
Cauliflower-like tumor
Older cats & dogs
ideally should be removed
malignant version exists
describe soft tissue sarcoma
General name for a number of mesenchymal tumors
Muscle, adipose, neurovascular, fascial, and fibrous tissue
Mostly malignant (see grade)
Similar pathologic appearance and clinical behavior
Solitary tumor in older dogs and cats
Skin and subcutaneous sites are most common
describe the soft tissue sarcoma
Tend to appear as pseudoencapsulated soft-to-firm tumors, but have poorly defined histologic margins or infiltrate through and along fascial planes, and they are locally invasive.
Local recurrence after conservative surgical excision is common
Tend to metastasize hematogenously in up to 20% of cases.
Regional lymph node metastasis is unusual
Histopathologic grade is predictive of metastasis, and resected tumor margins predict local recurrence.
Measurable or bulky (>5 cm in diameter) tumors generally have a poor response to chemotherapy and radiation therapy (RT).
describe equine malignant melanoma
80% of grey horses over the age of 15 will develop at least one melanoma tumor during their lifetime
Can be fatal
There is no available effective chemotherapy for horses.
Tumor of the melanocytes, the cells that produce skin pigment.
Most common location: underside of the tail, the perineal and peri-anal regions, penis and sheath in males
Can also be found: ear margins, anywhere on the head, jugular region, new or on the parotid salivary gland
It is also possible that the melanomas can spread internally, most commonly to the serosal surfaces of the liver, spleen, and lungs
Can be hard or soft, and appear either solitary or in clusters
Start off under the skin until they surface. They can become ulcerated and/or infected
How do melanoma’s develop
1- Melanomas develop slowly over years, and remain benign 10-20 years, without metastasis. Most common.
2- Benign melanomas that exist for months or years and suddenly develop malignant characteristics and spread rapidly externally and/or internally.
3- Melanomas are malignant from the start. Rare.
where can malignant melanoma metastasis to
Metastasis: lymph nodes, liver, spleen, skeletal muscle, lungs, and surrounding or within blood vessels throughout the body
Describe feline oral squamous cell carcinoma
Most common oral malignancy in the cat
Can originates from the jaw bones or the tongue
Owners may find a mass in their cat’s mouth which occurs mostly in the back of the mouth or under/on the tongue
It has an ability to grow invasively (locally), but does not tend to metastisize
Can be ulcerative or proliferative
No breed/sex predisposition, usually affects middle-aged cats
what are the symptoms of the feline oral squamous cell carcinoma
mass that can be ulcerative drooling weight loss, halitosis difficulty eating bloody discharge from the mouth
What are the environmental factors that contribute to oral SCC
Second Hand Smoke
flea collars
Diet
How do you diagnose oral SCC
Often not diagnosed until the tumour is advanced
Oral examination
An ulcerated, red, locally invasive lesion is highly suggestive of an oral tumor
Loose teeth can suggest bone structure is affected
Bloodwork to check overall health
Radiographs
Can reveal invasion of underlying bone
Biopsy of abnormal tissue
Used to confirm the presence of SCC and help stage the tumor
Important to obtain a large sample since feline oral SCC are frequently infected, necrotic, or inflamed.
Describe the treatment of feline oral SCC
Surgical removal is possible but can be difficult due to the aggressiveness and invasiveness that typically involves the bone. This means part of the jaw would need to be removed
Radiation therapy or chemotherapy alone is generally ineffective in the managing oral SCC.
The combination of the two can improve quality of life and overall survival time.
Pain medication can help reduce discomfort associated with the tumor.
Describe the prognosis of feline oral SCC
Extremely poor
1 year survival rate is less than 10% even with combinations of radiation therapy and chemotherapy
Most cats are euthanized withing 1-3 months because they cannot eat or drink and poor quality of life
What are the malignant oral tumors
squamous cell carcinoma
melanocyte tumor
fibrosarcoma
What are the benign oral tumors
epulides
How do you treat oral tumors
Surgery and RT are the most common treatments used for the local control of oral tumors.
What are the symptom of oral melanoma in dogs
Halitosis Drooling Bleeding from the mouth Change in food preference Change in chewing habits Decrease in appetite Chronic coughing Difficulty swallowing Weight loss
What causes canine oral melanoma
idiopathic
How do yu diagnose canine oral melanoma
Physical exam: Blood tests, UA, X-rays, abdominal ultrasound, MRI, fluid biopsy
Older dogs will have dark pigmented areas on the tongue, mouth and gums.
Look for anything unusual in the mouth pigmented or non-pigmented fleshy masses.
Metastasis: Head, neck, lymph nodes, liver, lungs, kidneys and sometimes bone tissue
how do you treat canine oral melanoma
Removal of tumor: Sometimes hard to completely remove because it may spread to the bone in the mouth. Can return even if completely removed.
Resistant to chemo.
Radiation: Remission in 70% of patients. Reoccurrence and spread still possible.
New vaccine restricted availability.
what is the prognosis from canine oral melanoma
5-7 months, but; Stage 1: 1 year Stage 2: 6 months Stage 3: 3 months Stage 4: 1 month
describe nasopharyngeal polyps in cats
Nonneoplastic, inflammatory masses
originating from either the middle ear or eustachian tube
can extend into the external ear canal or nasopharynx
Younger cats
Idiopathic
Describe the tumors of the liver
Primary tumors rare
Prognosis variable
Metastasis are frequent
Nodular hyperplasia
common diagnosis in older dogs
benign and probably does not represent a preneoplastic lesion
describe feline intestinal lymphoma
Can present as:
a purely intestinal infiltration
or a combination of intestinal, mesenteric lymph nodes and liver involvement
Tumors can be solitary but more commonly diffuse throughout the intestines
Common
Older cats, mostly small intestine
Often preceded by IBD
Describe perianal adenomas in animals
Benign sex-hormone dependent (spayed female, intact male)
Describe apocrine gland adenocarcinoma
Tiny primary tumor (often pea-size)
About 50% metastasis at diagnosis
Hypercalcemia (PU/PD)
Describe canine chondrosarcoma
Chondrosarcoma is a form bone cancer in dogs
The cancer starts in the cartilage and connective tissue found in joints, and/or ribs and nose.
It can cause bones to fracture easily as the tumour invades the bones.
It is mostly common in older dogs
How do you treat canine chondrosarcoma
Better prognosis if caught early and treated aggressively.
Amputation of the affected limb if no metastasis has occurred.
Radiation therapy if located in the nose.
Removal of the affected rib and portion of the lung if tumour is on rib followed by chemotherapy.
Inoperable tumours are treated with radiotherapy to try to prolong the life span.
Surgery is the only known affective treatment.
How do you diagnose canine chondrosarcoma
Xrays CBC Lymph biopsy Biopsy of tumour CT scan
describe canine osteosarcoma
Most common bone tumor found in dogs 5% of all canine tumors Malignant Can effect any breed Most common in large or giant breeds. Middle aged or elderly
What are the primary osteosarcoma tumor sites
Bordering the scapula Tarsus Carpus Stifle Commonly near growth plates
Where does canine osteosarcoma metastasize to
Lungs
other bones
lymph nodes
What are the risk factors associated with canine osteosarcoma
Slightly more in females than males
Higher in castrated males and spayed females (compared to intact)
What are the symptoms of canine osteosarcoma
Lameness Periosteal inflammation Microfractures Pathologic factors Swelling
how do you diagnose canine osteosarcoma
Orthopedic, neurologic and physical examination
X-rays (if lesion is in question – do a biopsy)
Biopsy through aspiration
Bone scan
how do you treat canine osteosarcoma
Aggressive treatment plan
Radiation therapy – palliative care not curative
Curative options include a combination of surgery, radiation therapy and chemotherapy
Standard treatment is amputation
what is the prognosis for osteosarcoma
Very good prognosis with amputation: resolves 100% of the pain
What is the aetiology and pathogenesis of insulinomas
Insulinomas are tumors of the pancreatic β cells (type of islet cell) which produce insulin
These tumors cause increased insulin production which result in hypoglycemia
The tumors respond to normal provocative stimuli that encourage a rise in insulin, but fail to respond to negative feedback when the insulin levels are too high
Insulinomas are very common in middle-aged and older ferrets ( greater than 3 years of age)
What are the clinical signs of insulinomas
Hypoglycemia will result in neurological signs such as mental dullness, sluggishness, lethargy, ataxia, seizures and coma
Prolonged, severe hypoglycemia can result in cerebral hypoxia and cerebral lesions
Other possible symptoms are nausea (which can cause the ferret to paw at its mouth), depression, hypersalivation, staggering, tachycardia, hypothermia, tremors, muscle fasciculations, nervousness and irritability
Owners may report that the ferret tends to sleep more frequently, be difficult to wake up, or stops in its tracks with a dazed appearance
It is important to note that these symptoms can come and go as blood sugar levels rise and drop
how do you diagnose insulinomas
One of the most common illnesses diagnosed in ferrets
Will be diagnosed using clinical signs, history, physical exam, blood glucose levels and
insulin levels
How do you treat ferret insulinoma
Surgery to remove the tumors (the tumors often grow back so several surgeries will likely be required)
Medication to manage insulin and glucagon levels (the dose will need to be increased as the illness progresses)
Diet is another huge component to managing this disease. All ferrets should be fed a high-protein ferret food, but this is especially important in sick ferrets
what is the prognosis for ferret insulinomas
Most insulinomas are eventually fatal
This is either because of hypoglycemic induced complications or because the tumors have spread to other organs
All that can be done is attempt to maintain a good quality of life for the ferret for as long as possible
describe pituitary adenoma
Common pituitary neoplasia of older dogs
Most common cause of cushing in horses.
Pituitary tumors account for approximately 15% of intracranial tumors
Frequently associated with either: -hyperadronocorticism
- Diabetes Insipitus
What are the clinical signs of pituitary adenoma
Non-neurological: weight loss, PU/PD, lethargy Neurological signs: cranial compression is rare but pressure on the optic chiasma may cause ocular changes
how do you diagnose pituitary adenoma
imagining with CT or MRI may be difficult, but a definitive diagnosis is usually done with a intraoperative or postmortem biopsy
Differential diagnosis: lymphoma, hypothalamic-pituitary trauma, dorsally expanding cysts, congenital malformations, inflammatory granuloma, etc.
how do you treat pituitary adenoma
corrective
hormonal therapy or
hypophysectomy
(removal of the pituitary gland)
what is the prognosis for pituitary adenoma
Prognosis depends upon the type and size of the tumour.
The prognosis for a pituitary tumor (if the client is willing to do treatments) is usually fairly good as the treatments are quite effective.
In serious unnoticed cases The entire hypothalamus may become compressed and replaced by the tumor.
How can you determine whether cushings disease is caused by the pituitary or the adrenal adenoma
If there is no change in Cortisol levels being released by the adrenal gland, then it is an Adrenal Adenoma.
If there is suppression of the adrenal gland, then the Cushing’s is being caused by a Pituitary Adenoma.
Describe pheochromocytoma
Adrenal gland tumor Older dogs Secretes catecholamines (episodic) episodic collapse, panting, anxiety, restlessness, exercise intolerance Malignant (40% metastasize) Good prognosis is no metastasis
Describe thyroid gland adenomas in dogs
Often benign adenoma found at necropsy Malignant: If clinical signs of hyperthyroidism (most non-functional) Older dogs Frequent metastasis
Describe hyperthyroidism
Multinodular adenomatous hyperplasia
Carcinoma rare
describe insulinoma
Pancreatic Beta-Cell Tumors
Hallmark of insulinoma
normal or elevated blood insulin concentration
in the presence of low blood glucose levels
Often malignant
50% metastasis
Medium and large breed dogs, older
What are the clinical signs of insulinoma
weakness, ataxia, collapse, disorientation, behavioral changes, and seizures
How do you treat insulinoma
Medical and surgical treatment
prognosis for dogs with insulinomas is good in the short term but guarded to poor in the long term
What is a gastrinoma
Often pancreatic, secretes gastrin Gastric acid hypersecretion Middle-aged dogs and older cats Non-specific clinical signs vomiting and weight loss melena, abdominal pain, anorexia, hematemesis, hematochezia, and diarrhea Often metastasis at diagnosis
What is a transitional cell carcinoma
Fairly common malignant tumor
Located in the trigone region of the bladder
15% metastasis at diagnosis
30% of dogs have abnormal cells in urine
What are the signs of the transitional cell carcinoma
hematuria, dysuria, pollakiuria
less commonly: lameness caused by bone metastasis
What is canine lymphoma
Is a common type of cancer in dogs.
Unregulated growth of malignant lymphocytes that often affects; lymph nodes, bone marrow, liver, and spleen.
Can also be seen in the eyes, skin, and gastrointestinal tract.
It can be small cell lymphoma; progresses very slowly and is difficult to treat. There is also large cell lymphoma; progresses quickly but responds very well to chemotherapy.
What are the 5 stages of canine lymphoma
Stage I: Ailment restricted to a single lymph node.
Stage II: Regional lymphadenopathy (restricted to one side of diaphragm).
Stage III: Generalized lymphadenopathy (enlargement of lymph nodes)
Stage IV: Enlargement of the liver and spleen or hepatosplenomegaly (with or without lymphadenopathy).
Stage V: Bone marrow, CNS (Central Nervous System), or involvement of other extranodal sites.
what are the symptoms of canine lymphoma
Firm, enlarged, non-painful lymph nodes. Other common symptoms include loss of appetite, lethargy, weight loss, swelling of the face or legs (edema), and occasionally increased thirst and urination.
how do we diagnose canine lymphoma
Best way is to perform a biopsy; you are able to differentiate between T and B cells with special stain because they respond differently to treatment.
how do we treat canine lymphoma
Most effective therapy is chemotherapy. In some situations, surgery or radiation therapy may also be recommended.
what is the prognosis for canine lymphoma
Depends on what type of lymphoma the dog has and the type of chemotherapy. The average for multicentric lymphoma is 9-13 months.
describe leukemia
Many different types of leukemia Myeloid: white blood cells Erythroid: RBC All from bone marrow Can be acute or chronic Acute: high cell counts, immature cells Chronic: moderate cell counts, mature cells Bone marrow examination important
what are the signs of multiple myeloma
Bleeding (nose, gums)
Lameness
PU/PD
Elevated globulins
describe the prognosis of multiple myeloma
Dog: good for initial control of tumor and a return to good quality of life (median 540 days)
Cats: 4 months
describe plasmacytoma
Local & Benign form of plasma cell tumor
Older dogs
Limb, head, lips
Conservative surgical excision
describeb mast cell tumors in dogs
Mast cells are found in the connective tissues mostly in the vessels and nerves that are located close to the external surfaces.
Boxers, bulldogs, pugs, and Boston terriers appear to be more susceptible to mast cell tumors than other breeds. Dogs affected with a mast cell tumor are around 8 years old but studies show that there has been cases of mast cell tumor seen in less than 1 year old dogs
where is the primary tumor site for mastocytoma
skin, nose, mouth, lungs
describe the metastasis of mast cells
Depending on the stages, stage 2 will metastasize into surrounding lymph nodes and stage 4 will metastasize to other organs.
How do you diagnose mast cell tumors
Fine needle aspiration Cytology Biopsy surgical removal radiation therapy (if metastasis occurs)
What is the prognosis for a mast cell tumor
The prognosis will depend on the growth of the tumor
If the tumor grows more than 1 cm per week, the animal only has 25% chances of surviving more than 30 weeks
If the tumor is located at one specific area and does not grow rapidly for several months, it is known to be benign
What are some complications associated with mast cell tumor
In some cases, you might noticed an enlargement of the lymph nodes located around the area of the tumor
Some masses can be inflammed and itchy due to high level of histamines in the actual tumor
Enlarged liver and enlarged spleen are characteristic of wide-spread mast cell cancer
What is a thymoma
Older (9-10 yo) dogs (and cats)
Neoplasms of thymic epithelial cells
Benign vs malignant based on surgery
What are the clinical signs of a thymoma
Lethargy, coughing, tachypnea, and dyspnea
What can a thymoma cause in some animals
myasthenia gravis (in 40% of dogs)
What is myasthenia gravis
Autoimmune disease of the neuromuscular junction
causing muscular weakness and excessive fatiguability
Megaoesophagus (regurgitation)
3% of dogs with MG have a cranial mediastinal mass
What are histiocytic diseases
Neoplasia of macrophage (and related cells)
What is a histiocytoma
Nodular skin tumor of young dogs (head/neck)
Very common
Benign, regresses spontaneously
What is a histolytic sarcoma
Bernese Mountain dogs, rottweilers, retrievers
Spleen, liver, lungs
Very poor prognosis
Describe mammary tumors in dogs
Common in intact females Heterogenous group of tumors (10+) More research needed Impacts the course of action/treatment Metastasis common
Describe mammary tumors in cats
Siamese cat younger, overrepresented
Intact cats
The vast majority of feline mammary tumors are malignant (85% to 95%)
with an aggressive biologic behavior,
lymphatic invasion and lymph node metastasis are more common at the time of initial diagnosis than in dogs
Needs aggressive surgery
Describe a canine prostate tumor
Older dogs, intact and neutered (slightly more)
At the time of diagnosis
Most tumor are locally invasive
High propensity for regional and distant metastasis
Bones (lumbar vertebra and pelvis)
what are the signs of a canine prostate tumor
hematuria, dysuria, stranguria,
dyschezia, tenesmus
