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
