Specific disorders of the skin Flashcards
1
Q
What are the four surgical margins for tumour removal?
A
2
Q
What are the 3 different histologic margin categories following tumour removal?
A
3
Q
In general, how long after surgery is it advised to start chemotherapy?
A
7-10 days
4
Q
In general, how long after surgery is it advised to start radiation therapy?
A
1-3 weeks (the acute inflammatory phase and proliferative phase are most sensitive to radiation effect).
5
Q
How long should surgery be delayed following pre-operative radiation therapy?
A
Ideally 3-4 weeks to allow clearance of acute radiation effects.
6
Q
Describe the WHO-TNM classification system for tumors of epidermal or dermal origin.
A
7
Q
Do mesenchymal cell tumours more commonly spread by hematogenous or lymphatic routes?
A
Hematogenous. Epithelial tumours spread more commonly by lymphatics.
8
Q
What size pulmonary nodules can thoracic radiography and CT scan detect, respectively?
A
Radiographs: 1-2 mm
CT scan: 5-9 mm
9
Q
What are the functions of the lymphatic system?
A
- Transport of lymph from tissues and organs, lipids from the intestine and liver, and waste products and fluids from the local sites.
- Immune response. Lymphatic vessels drain into lymphatic ducts and then into lymph nodes.
10
Q
Is lymph flow passive or active?
A
Both. Active constriction of smooth muscle in the lymphatic walls, passive through outside pressure from musculature with lymphatic valves preventing retrograde flow.
11
Q
What are the primary cell types in the cortex and medulla of the lymph node?
A
Cortex: B and T lymphocytes.
Medulla: lymphocytes, macrophages and plasma cells. Sinuses between medullary cords help to filter and phagocytose foreign material.
12
Q
What is lymphangitis? What are some clinical signs?
A
Secondary inflammation of the lymphatic system, generally secondary to systemic disease.
Can cause pyrexia, anorexia and depression. Persistent edema can result in irreversible thickening of the skin and subcutis.
13
Q
What is lymphadema?
A
Reduced lymphatic transport capacity resulting in interstitial edema. Can be primary (congenital and rare) or secondary.
14
Q
Aside from lymphadema, what are some other potential causes of interstitial edema?
A
High lymphatic load from venous hypertension, portal hypertension, venous obstruction, arteriovenous fistula, hypoproteinemia. Increased vascular permeability from vasculitis.
15
Q
What are some causes of secondary lymphadema?
A
Neoplasia, trauma, surgery, radiation therapy, parasitic infection, chronic lymphangitis.
16
Q
What are some treatment options for lymphadema?
A
Bandaging, benzopyrones (coumarin) although may cause hepatotoxicity and not reported in veterinary medicine. Diuretics have no effect as edema not caused from water retention.
17
Q
What diagnostics can be used to identify lymphadema?
A
Direct contrast lymphangiography or indirect lymphoscintigraphy +/- CT or MRI.
18
Q
What are the 5 types of round cell tumours observed in dogs and cats?
A
Lymphoma, histiocytoma (or malignant histiocytosis), plasma cell tumour, mast cell tumour, TVT.
19
Q
What is the most common skin tumour in dogs and cats, respectively?
A
Dogs: mast cell tumour
Cats: SCC
20
Q
What is the typical treatment for papillomatosis in young dogs?
A
Nothing, usually resolve within 3 months. Thought to have an underlying viral cause.
21
Q
What is actinic keratosis?
A
A precancerous solar induced lesion which may progress to SCC.
22
Q
What is Bowenoid carcinoma in situ?
A
A rare form of multicentric SCC in situ presenting as multifocal crusted plaques.
23
Q
In what percentage of SCC in dogs and cats are ultraviolet light specific mutations in the P53 gene reported?
A
Dogs: 30-38%
Cats: 40-82%
24
Q
What are the most common locations of SCC in dogs and cats?
A
Dogs: Nail bed, scrotum, legs and anus.
Cats: pinnae, eyelids, temporal area, nasal planum.
25
Which breeds are most commonly affected by nasal planum SCC in dogs?
Male labrador and golden retrievers
26
White cats have a ___ times higher risk of SCC compared to cats of other coat colours?
13
27
What is the median survival time for cats following pinnectomy or nasal planectomy for SSC?
673 days
28
Based on tumour stage, when should aggressive surgery indicated over alternative therapies for cutaneous SCC?
Aggressive surgery gives the best prognosis for tumours greater than stage T2.
29
Name 6 alternative therapies for cutaneous SCC aside from surgical excision.
1. Cryosurgery
2. Plesiotherapy (form of superficial radiation therapy)
3. Radiation therapy
4. Photodynamic therapy
5. Chemotherapy
6. Immunomodulatory therapy
30
For what size SCC lesions is cryosurgery considered an appropriate treatment option?
Up to 5mm in diameter. MST of 682 days.
31
What depth of tissue penetration does strontium plesiotherapy achieve when treating SCC?
3mm
32
Is photodynamic therapy appropriate for treatment of deep cutaneous SSC lesions?
No - only has superficial penetration. In one study had 100% control of T1 non invasive tumours and only 18% for T2 invasive tumours.
33
What is electrochemotherapy?
Use of locally applied electrical field pulses to induce an increased uptake of a systemically administered chemotherapeutic drug.
34
In what percentage of canine and feline cutaneous SCC is there COX-2 expression?
100%, although effects of NSAIDs on SSC have not been investigated in dogs and cats. This is compared to only 9-18% of oral feline SCC.
35
What is an example of an immunomodulatory agent used in the treatment of cutaneous SSC?
Imiquimod. Has shown efficacy for actinic keratosis in humans. Less favourable results in cats with some systemic side effects.
36
What axial pattern flap is useful in reconstruction of rostral facial defects following SSC excision?
Angularis oris axial pattern flap
37
What are the recommended surgical margins for excision of cutaneous SSC in dogs and cats?
Cats: 5mm
Dogs: nasal planum or invasive cutaneous tumours (T3/T4) at least 2cm
38
List two potential prognostic factors for SSC.
Tumour stage, proliferation fraction, epidermal growth factor receptor expression.
39
Which breeds of dog are reported to have an increased incidence of basal cell tumour?
Cocker spaniels and poodles. Frequently occur on the head, neck, or shoulders.
40
Are basal tumours considered aggressive in behaviour?
No, despite often having a high mitotic rate in cats they generally behave in a benign fashion. Surgical excision is typically curative.
41
What is the recommended treatment for sebaceous gland adenocarcinomas or aggressive sweat gland malignancies?
Wide surgical excision.
42
Is cytology useful in differentiating between perianal adenomas and adenocarcinomas?
No, histology is typically required.
43
Are perianal adenomas or adenocarcinomas more common?
Adenomas (58-96% of cases).
44
Are perianal adenomas and adenocarcinomas both hormone responsive?
No, only perianal adenomas demonstrate sex-hormone responsiveness (most regress following castration of intact males).
45
What percentage of perianal adenocarcinomas are have metastasis at the time of diagnosis?
15% (most common sites are the regional lymph nodes, lungs, liver, kidneys and bone although distance metastases are uncommon).
46
What factor has been shown to significantly influence disease free intervals with perianal adenocarcinoma?
Tumour stage
47
How much of the anal sphincter can be removed with only transient loss of continence?
50%
48
In what percentage of dogs is hypercalcemia reported with anal sac adenocarcinoma (AGASACA)?
27-53%
49
What is the percentage metastatic rate of canine AGASACA at diagnosis?
36 - 96%
50
What is the most common site of metastasis in canine AGASACA?
Sublumbar lymph nodes
51
In what percentage of dogs is AGASACA an incidental finding?
39%
52
What imaging modalities may be useful in ruling out bone metastasis in canine AGASACA?
Radiography, nuclear scintigraphy
53
What are some negative and positive prognostic factors for canine AGASACA?
Positive: surgical excision and lymphadenectomy.
Negative: tumor stage, hypercalcemia, lack of therapy.
54
What is the MST for canine AGASACA?
16-18 months (with surgery alone 7.9 - 16.6 months). Longest survival times have been reached with a combination of surgery, radiation and mitoxantrone chemotherapy.
55
What is the reported local recurrence rate after marginal excision of canine AGASACA?
7 - 45%
56
Is hypercalcemia a common feature of AGASACA in cats?
No
57
What is the reported MST for AGASACA in cats following marginal excision?
3 months
58
Is surgical excision of hair matrix tumours typically curative?
Yes
59
Describe the TMN staging system for soft tissue sarcomas
60
Are soft tissue sarcomas more common in small, medium, or large breed dogs?
Medium or large
61
What are the three described grades of soft tissue sarcomas?
Grade 1/low
Grade 2/intermediate
Grade 3/high
Grade is predictive of both distant metastasis and local recurrence.
62
In what percentage of patients is histologic grade of STS underestimated on pre-operative biopsy?
29% (overestimated in 12%)
63
What is the most common site of distant metastasis for STS?
Lungs. Reported overall rate of metastasis is 6-17% (<13% grade 1 and 2, 41% - 44% grade 3)
64
What is the most important prognostic factor for local recurrence of STS?
Clean surgical margins. Other negative reported factors include size, and positive factors are tumor mobility, expansile growth, and reduced depth of invasion.
65
What are the recommended surgical margins for STS?
2 - 3 cm lateral margins, one fascial plane deep
66
What are treatment options following incomplete excision of STS?
Reexcision or radiation (comparable response rates with ~15% recurrence). MST following radiation appears to be grade dependent (940 days for grade 3, not reached for grades 1 and 2). MST after surgery alone for grade 3 tumours: 236-856 days.
67
What was the MST for cats undergoing surgical excision of soft tissue sarcomas? Was this affected by completeness of excision?
MST: >16 months
Yes, MST with incomplete excision <9 months.
68
What is the recurrence rate of STS following marginal excision?
Grade dependent (grade 1 = 7%, grade 2 = 34%, grade 3 = 75%). On the distal limb grade 1 tumours were associated with prolonged survival following marginal excision in 1 study (MST not reached), with histologic margin not affecting survival time.
69
Is radiation therapy as a single-modality therapy considered a definitive treatment option for soft tissue sarcoma?
No, considered palliative as does not result in a durable response. More effective following surgical excision or debulking.
70
Does chemotherapy improve prognosis for patients with soft tissue sarcoma?
Uncertain, but typically recommended in high grade soft tissue sarcomas due to the propensity to metastasize (40%).
71
Do perivascular wall tumours have a more or less aggressive biologic behaviour to canine STS in general?
Less aggressive. Expansile lesions also more common the distal extremity, resulting in equal rate of recurrence compared to other locations even with marginal excision.
72
What is histologically low grade and biologically high grade fibrosarcoma?
A subtype of fibrosarcoma that occurs in young dogs in the oral cavity. Appears histologically low grade but has high grade biologic behaviour. Prognosis is guarded.
73
What immunohistochemistry marker can be used for differentiation of peripheral nerve sheath tumours?
Vimentin. They arise from Schwann cells, perineural fibroblasts, or both.
74
What is the reported incidence of feline injection site sarcomas?
1 to 10 per 10,000 cats
75
Which vaccines are associated with the highest risk of feline injection site associated sarcoma?
Inactivated vaccines. Two-fold increased risk for rabies, and five-fold for FeLV.
76
What is the reported local recurrence rate for feline injection site sarcomas?
70%
77
What is the most common tumour type associated with feline injection site sarcoma?
Fibrosarcoma (79-93%)
78
What is the most common site of metastasis for feline injection site sarcomas?
Lungs (0 - 24%)
79
What are significant prognostic factors for survival for feline injection site sarcomas?
Aggressive surgery with wide margins, local recurrence, occurrence of distant metastasis, number of surgeries, and size. Most important prognostic factor for local recurrence is clean surgical margins. Aberrant cytoplasmic p53 expression associated with shorter time to recurrence.
80
What is the MST for feline injection site sarcomas?
576 - 608 days with surgery alone. Disease free interval much shorter after marginal excision (325-419 days wide excision, 79 days marginal).
81
What surgical margins are recommended for feline injection site sarcomas?
With 4-5 cm lateral margins and one fascial plane deep local recurrence of 39% reported. With 5cm lateral margins and 2 fascial planes deep 14% recurrence (overall median survival 901 days).
82
Is radiation therapy beneficial in instances of marginal excision of feline injection site sarcomas?
Yes, has been shown to increase disease free interval and survival times. More effective on microscopic rather than macroscopic tumour.
83
Is chemotherapy useful in the treatment of feline injection site sarcomas?
Uncertain. Use of tyrosine kinase inhibitors do not seem effective. Immunotherapy also being investigated.
84
When should removal of a mass at an injection site be considered?
If a mass exists for more than 3 months after injection, increases in size significantly within 4 weeks, or is larger than 2cm in diameter.
85
Are females or males predisposed to infiltrative lipomas?
Females, labrador retrievers overrepresented
86
What is the reported local recurrence rate after surgical excision of infiltrative lipoma?
36 - 50%. Radiation therapy may improve survival (MST 40 months).
87
How do infiltrative lipomas differ from lipomas?
Infiltrative lipomas do not have a capsule and are infiltrative into surrounding tissues.
88
Are fine needle aspirates of liposarcoma more or less cellular than lipomas?
Much more cellular
89
What is the MST for liposarcoma?
1188 days after wide excision. 649 after marginal excision.
90
How are cutaneous hemangiosarcomas staged?
Based on tumor depth and invasion.
Stage 1: confined to dermis (MST 780 days).
Stage 2: extending into subcutaneous tissues.
Stage 3: invading muscle and fascia.
Stage is associated with prognosis. Stage II and III had 60% metastasis to the lungs in one study, MST of 172-307 days. Chemotherapy may be beneficial due to high metastatic rate.
91
Where are cutaneous hemangiosarcomas most likely to occur?
Sparsely haired and poorly pigmented skin of the ventral abdomen, medial thigh, inguinal region (may be associated with ultraviolet solar exposure).
92
What are prognostic factors for cutaneous hemangiosarcoma?
Completeness of excision, tumor size (<4cm), metastasis at diagnosis, gross disease.
93
Is tumor metastasis more or less common in cats with cutaneous hemangiosarcoma compared to dogs?
Appears less common. Good long term survival (MST 1460), even in cases of incomplete excision.
94
What are some prognostic factors reported for feline cutaneous hemangiosarcoma?
Tumor site (dermis or subcutis), clean margins, mitotic rate.
95
Describe the blood supply to the mammary glands in dogs.
Three cranial mammary glands are supplied by the lateral thoracic artery and deeply by the cranial superficial epigastric, and intercostal branches from the internal thoracic.
Two caudal glands are supplied by the caudal superficial epigastric, and deeply by branches of the deep circumflex iliac and cranial abdominal arteries.
96
Describe the lymphatic drainage of the mammary glands in dogs.
Glands 1 and 2: axillary lymph center.
Glands 3 and 4: axillary or inguinofemoral lymph center.
Gland 5: inguinofemoral lymph center and medial iliac lymph nodes.
Additional variable lymphatic drainage to the sternal lymph nodes, superficial cervical, and popliteal nodes.
Anastomoses between glands are occasionally seen.
97
Describe the lymphatic drainage of the mammary glands in cats.
Thoracic glands: axillary.
Abdominal glands: inguinal.
No anastomoses between glands seen in this species.
98
How many mammary glands do dogs and cats have?
Dogs: 5
Cats: 4
99
Which breed of dog might be predisposed to malignant mammary neoplasia?
German shepherds
100
The risk for benign canine mammary tumours is how much higher than the risk for malignant mammary tumours?
2 - 5 times higher. Although may be closer to 50/50 with large percentage of intact dogs.
101
What is the most important risk factor for development of canine mammary neoplasia?
Time of spaying. Risk for mammary neoplasia in spayed compared to intact female dogs is 0.5% when spayed before the first estrus, 8% when spayed before the second estrus, and 26% when spayed after the second estrus but before 2 years of age. Spaying at a later age may reduce risk of benign but not malignant neoplasia.
102
Are malignant or benign canine mammary neoplasms more likely to express estrogen and progestin receptors?
Benign (>90% of tumours), compared to 50% for malignant tumours suggesting that these tumours may lose their hormone dependency.
Estrogen receptor expression is also more common in clinical stages I and III and tumours smaller than 5cm.
103
Describe the TMN staging system for canine mammary neoplasia
104
What is inflammatory canine mammary carcinoma?
Rapidly progressive, highly metastatic (8-100%) disease seen in sexually intact dogs (accounts for 8% of canine mammary tumours). MST is 25-60 days.
Can be primary or secondary (evolving abruptly from long-standing mammary nodule or following surgical excision of a noninflammatory mammary tumour).
105
Which glands are most frequently affected by canine mammary neoplasia?
Glands 4 and 5.
106
Is canine mammary neoplasia more frequently single or multiple?
Multiple (>60% of cases)
107
Does a benign diagnosis on FNA of a mammary mass exclude malignant neoplasia?
No, malignant tumors often lack cytologic signs of malignancy
108
What is the reported incidence of distant and regional lymph node metastasis at the time of diagnosis for canine mammary neoplasia?
Distant: 6 - 38%. Most commonly the lungs.
Regional LNs: 44-55%
109
What surgical margins are recommended for malignant canine mammary neoplasia?
2 - 3 cm margins
110
In male dogs are mammary neoplasms for likely to be malignant or benign?
Benign and surgical excision is often curative
111
What are surgical options for canine mammary neoplasia removal, and when might each be indicated?
Lumpectomy: small (<0.5cm) benign tumours.
Simple mastectomy: tumours located in the center of the gland where removal of a single gland achieves 2 - 3 cm margins. May be more difficult than regional mastectomy due to confluence of the glands.
Regional mastectomy: en bloc removal of glands 1-3 or 3-5 depending on location of the neoplasia.
Chain mastectomy: complete removal of one (unilateral) or both (bilateral) mammary chains. Indicated if there are multiple nodules, tumors in the third gland, and large masses (>1cm) with fixation or suspected malignancy.
112
What percentage of dogs developed a new mammary tumor in the remaining ipsilateral gland after regional mastectomy for a single tumour?
58%
113
What are some prognostic factors for canine mammary neoplasia?
Histologic tumour type (including grade and invasiveness), tumour size, lymph node and distant metastasis (stage).
114
What is the median survival time of malignant mammary tumours in dogs?
Stage T1: 22 months
Stage T2: 14 months
Stage T3: 40 weeks
In another study if there was no metastatic disease MST was 28 months, compared to 5 months with metastatic disease.
115
Does the presence of micrometastatic disease of the inguinal lymph nodes (<2mm) affect survival of dogs with mammary neoplasia?
No. Only macrometastatic disease (>2mm) was shown to affect survival.
116
Tamoxifen (an estrogen receptor blocker) is routinely used in cases of human mammary neoplasia. Is it considered useful in dogs?
No - because there does not seem to be a protective effect of estrogen suppression except when performed in young animals (< 2 years)
117
What percentage of feline mammary neoplasia is malignant?
85%
118
Cats spayed before 6 months and 1 year have a ___ and ___ reduction in risk for mammary carcinoma respectively.
91%, 86%.
Spayed cats had half the risk of developing mammary neoplasia in one study (not accounting for age of spay).
119
What percentage of feline mammary carcinomas show COX-2 expression?
87-96% (compared to 0% in normal tissue). Ki-67 proliferation marker also increased significantly with malignancy, and VEGF expression correlated with histologic grade and survival.
120
In what percentage of cases of feline mammary neoplasia is metastasis observed?
80%
121
More than ___ of feline mammary tumours are adenocarcinomas.
80%
122
What is fibroadenomatous hyperplasia?
Benign mammary lesion in cats, that results in massive mammary gland enlargement due to high levels of progestins. Most observed in young, sexually intact cats.
123
What are treatment options for fibroadenomatous hyperplasia?
Removal of hormonal influence +/- mastectomy. Progesterone blocking drugs (aglepristone) may also be effective.
124
What is the treatment of choice for feline mammary tumours?
Radical mastectomy of the affected side. Should include the underlying muscle/fascia if the tumour is attached.
125
Describe the staging system for feline mammary neoplasia.
126
What are the most important prognostic factors for feline mammary neoplasia?
Histologic grade, lymph node or lymphatic invasion, tumour size, extent of surgery.
For tumours <2cm MST was >3 years, tumours 2-3 cm MST 15-24 months, tumours larger than 3cm MST was 4-12 months.
127
Does ovariectomy decrease recurrence of feline mammary neoplasia?
No, similar to male dogs there is decreased hormone dependency of malignant neoplasms.
128
Is mammary neoplasia more commonly benign or malignant in male cats?
Malignant. MST 344 days. Tumor size significantly related to survival.
129
Which breeds of dog are pre-disposed to mast cell tumour development?
Pugs and Boxers are more likely to develop low or intermediate grade mast cell tumours, gonadectomized Vizslas have an increased risk for tumour development.
130
What is the most common location for canine mast cell tumours?
Trunk (42-65%), then limbs (22-43%), and head and neck (10-14%).
131
What percentage of canine mast cell tumours are affected by a mutation of the c-kit protooncogene?
15 - 50% (this results in activation of KIT protein, a transmembrane tyrosine kinase receptor, independent of stem cell factor).
KIT expression associated with tumour grade, recurrence and death.
132
What percentage of dogs with mast cell tumours are presented with multiple tumours?
25%
133
What are some potential side effects of canine mast cell degranulation?
Darier sign: associated with a worse prognosis.
GI ulceration
Anaphylactic shock
Delayed wound healing
The use of histamine blockers is recommended.
134
What are the most common locations for canine mast cell metastasis?
Regional draining lymph nodes, then liver and spleen. Involvement of the lungs is uncommon.
Visceral mast cell disease is typically secondary to spread from a primary cutaneous lesion.
135
What are the grading systems for canine mast cell tumours?
Patnaik: well differentiated (grade 1), intermediate (grade 2), undifferentiated (grade 3).
Kiupel: low and high grade (85% of Patnaik grade 2 tumours are low-grade).
136
What is the MST for canine mast cell tumours based on the Kiupel grading system?
Low grade: 690 - 1452 days
High grade: 110 - 208 days
137
Why is the suggested TMN staging system for canine mast cell tumours problematic?
Multiple cutaneous tumours are automatically categorized as stage 3 and therefore poorer prognosis, however often multiple cutaneous mast cell tumours are independent primary events.
138
What is the rate of lymph node metastasis in low and high grade mast cell tumours, respectively?
Low grade: 15%
High grade: 30%
139
Describe survival and recurrence for canine mast cell tumours.
140
What margins are suggested for surgical excision of mast cell tumours?
3 cm lateral margins with one fascial plane deep.
Although grade 1 tumours have been successfully excised with 1cm lateral margins, and grade 2 tumours with 2cm lateral margins.
Using a proportional approach resulted in 15% incomplete excisions in one study.
141
List 5 prognostic factors associated with canine mast cell tumours.
1. Age (older = worse prognosis)
2. Presence of local clinical signs
3. Tumour size (>3cm), rate of growth (slow growing tumours present for greater than 6 months more likely to be benign.
4. Tumour location (oral/perioral tumours have a worse prognosis and higher rate of metastasis; 55-59%. Preputial, scrotal and subungual may also be more malignant).
5. Clinical stage (lymph node metastasis).
6. Incomplete margins (more pertinent for high grade or grade 3 tumours).
7. Staining for Ki-67, proliferating cell nuclear antigen (PCNA), increased AgNORs count, mitotic index, presence of c-kit mutations.
142
What are the most effective therapies for incompletely excised low- to intermediate grade mast cell tumours without metastasis?
Wide recut or radiation therapy. These increase survival (MST >2000 days compared to no additional local therapy, MST 710 days).
143
When might the use of chemotherapy be beneficial in the treatment of canine mast cell neoplasia?
Grade 3, high risk grade 2, and stage 2 (presence of LN metastasis) and higher tumours.
144
Oral prednisone treatment has been shown to reduce the size of mast cell tumours in ___ to ___ of cases.
20 - 75%
145
Aside from chemotherapy and radiation therapy what are some additional adjunctive therapies that have been described for the treatment of canine mast cell tumours?
Electrochemotherapy, hypotonic shock, tyrosine kinase inhibitors (masitinib, toceranib).
146
In grade 2 stage 2 canine mast cell tumour disease what treatment approach has led to similar outcomes as for stage 1 patients?
Multimodal therapy with surgery, locoregional lymph node excision and/or chemotherapy and/or radiation.
147
What are the two types of feline mast cell tumours reported?
Mastocytic (classified as well differentiated and poorly differentiated) and histiocytic (or atypical poorly granulated mast cell tumour).
The histiocytic form has been reported to regress spontaneously in 4 - 24 months.
148
What is the most common type of feline mast cell tumour?
Well differentiated mastocytic form (50-90% of cases).
149
Are visceral or cutaneous mast cell tumours more common in cats?
Visceral (intestinal and splenic in particular)
150
What is the rate of metastasis for feline cutaneous mast cell tumours?
0 - 22%. Generally considered a behaviourally benign disease. The visceral form is much more likely to metastasize.
151
How frequently is mastocytemia seen with feline cutaneous mast cell neoplasia?
19-31% (compared to 100% with splenic mast cell tumour). Recommend examination of buffy coat in all instances.
152
What is the rate of recurrence after surgical resection of feline mast cell tumours?
0-33%. Completeness of excision does not seem to influence recurrence.
153
What are some prognostic factors for feline mast cell tumours?
Presence of greater than 5 cutaneous tumours, visceral rather than cutaneous tumours, mitotic index, cytoplasmic KIT staining pattern.
154
What is the prognosis for feline splenic and intestinal mast cell tumours?
Splenic: MST of 12-19 months with splenectomy.
Intestinal: MST < 2 months. Recommend excision with 5-10 cm of normal bowel.
155
What are the two forms of histiocytic sarcomas?
Localized and disseminated.
Localized cutaneous histiocytic sarcoma may carry a reasonable prognosis if detected early and aggressively excised in the absence of metastatic disease. Prognosis for localized internal lesions tends to be poor due to late detection.
156
Is cutaneous plasmacytoma generally benign or malignant?
Generally benign (in contrast to the systemic form malignant myeloma)
157
Is spontaneous regression common for TVTs?
Yes, often occurs within 3 months. Regression unlikely to occur in immunocompromised animals, very young dogs, or if the tumour has been present for more than 6 months. Therapy consists of vincristine.
158
What is the recurrence rate after surgical treatment of TVT?
30-75%. Not normally recommended over other therapies.
159
In what location are amelanotic melanomas most commonly seen?
The oral cavity
160
What are the surgical margins recommended for malignant melanoma excision?
Wide (>2cm) or radical excision (digital tumours)
161
How is melanoma location related to the likelihood of malignancy in dogs?
85% of melanomas in the skin show benign behaviour. Melanomas of the oral cavity, mucocutaneous junctions, and 50% around the nail bed are more commonly malignant.
In one retrospective study tumours of the gingiva, palate, tongue and pharynx were most lethal (MST 147 days), then foot or inner lips (MST 676), then skin (59% survival at 874 days). Metastasis was reported in 59%, 38%, and 12% respectively.
162
What are the most common locations for metastasis of malignant melanoma?
Regional lymph nodes and lungs (14-67% of oral melanomas) most common, can also spread to spleen, brain and heart.
163
Aside from tumour location what are other prognostic factors for canine melanoma?
Disease stage, histologic parameters (mitotic index, detection of Ki-67 and PCNA).
164
Are cutaneous melanomas more likely to be malignant or benign in cats?
Malignant (42 - 68% of cats). MST 4-6 months, although survival times of up to 3 years have been reported for non-ocular cutaneous melanoma.
165
Is chemotherapy an effective adjunctive treatment for melanoma?
No - seem minimally chemotherapy responsive.
166
What is the MOA of the melanoma vaccine?
It is a human tyrosinase DNA vaccine which leads to the production of antityrosinase antibodies. Tyrosinase is a membrane glycoprotein that shows a high level of expression in canine melanomas.
Additional immunotherapies have also been experimentally investigated.
167
What are the most common canine digital tumours in order of decreasing frequency?
SSC
Melanoma
STS
Mast cell tumour
Osteosarcoma
168
What percentage of canine digital tumours have evidence of bone lysis on radiographs?
75%
169
What percentage of digital lesions are malignant in dogs?
55% (remaining 25% are inflammatory lesions, and 16% benign lesions).
170
Is survival better for SCC originating from the subungual region or other areas of the digit in dogs?
Subungual region (1 year survival of 95% compared to 60%). Metastasis at the time of diagnosis uncommon.
171
Is SCC of the digit more common in light or dark haired dogs?
Large dogs with black hair coats
172
What are the most common primary nail bed tumours in cats?
SCC or fibrosarcoma. Metastasis from other locations is common.
Metastatic spread from a primary pulmonary lesions (feline lung-digit syndrome) often affects multiple digits.
173
What is the median survival time for digital melanoma in dogs based on tumour stage?
Stage 1 and 2: not reached
Stage 3: 321 days
Stage 4: 76 days
174
What are the surgical treatment options for interdigital pyoderma?
Podoplasty or fusion podoplasty
175
In which breed are pilonidal sinuses most common?
Rhodesian ridgebacks. In severe cases may extend to the spinal dura mater.
176
In what location are pilonidal sinuses most common?
Dorsal midline of the cervical or cranial thoracic regions.
177
When is surgical excision of pilonidal sinuses recommended?
When there are neurologic or chronic dermatologic signs.
178
In which breeds are nasal dermoid sinus cysts reported?
Golden retrievers, spaniels and shih tzus
179
According to Ferrari 2020 in Vet Surg using technetium 99 and methylene blue sentinel lymph node mapping for dogs with cutaneous and subcutaneous mast cell tumours, what percentage of SNL did not correspond with the expected regional lymph node?
63%
180
According to Lapsley 2020 in Vet Surg, in what percentage of dogs did the sentinel lymph node for integumentary mast cells tumours differ from the local regional lymph node? In what percentage of dogs did histopathology of the SLN lead to a change in recommendation as compared to FNA of the regional LN?
25% and 50%
181
In a study by Karbe 2021 in Vet Surg, what percentage of scar revisions for inadequately excised cutaneous mast cell tumours contained residual mast cell tumour? Was the presence of residual mast cell tumour predictive of recurrence?
27% of resected scars contained residual mast cell tumour. The presence of tumour (or margin status of the scar revision) were not predictive of recurrence. Tumour grade was the only factor associated with disease progression and locoregional recurrence (more likely in grade III)
182
In a study by Cherzan 2023 in Vet Surg, what was the MST for subcutaneous mast cell tumours? What were 2 negative prognostic indicators for survival?
MST 1722 days.
Lymph node metastasis and local recurrence were negative prognostic indicators for survival (MST 551 days).
Local recurrence occurred in 18% of patients, and lymph node metastasis in 28%.
183
In a study by Litterine-Kaufman 2019 in JAVMA, were dogs with more than 1 mammary mass more likely to have malignant neoplastic disease? What percentage of masses were malignant and benign?
No, the presence of a solitary or multiple mammary masses was not predictive of malignancy. Neither were age or reproductive status.
85% of masses were classified as benign, 15% as malignant.
184
In a study by Chu 2020 in JAVMA, was using a conservative (equal to tumour diameter for tumours <2cm, >2cm for larger tumours), non-inferior to wide (3 cm) lateral margins for excision of grade I and II cutaneous mast cell tumours?
Yes, no difference in tumour free histologic margins between the conservative and wide margin groups.
185
In a study by Crownshaw 2020 in JAVMA, what was the overall survival time in patients with incompletely excised high grade soft tissue sarcomas treated with definitive intent radiation therapy? What were the metastatic and local recurrence rates?
981 days
Metastatic rate of 24%, local recurrence rate of 20%.
186
In a study by Evans 2021 in JAVMA, what 3 factors were associated with an increased rate of complications following mastectomy? What was the overall rate of complications?
Increased body weight, bilateral mastectomy, and administration of post-operative antimicrobials were associated with the highest risk of complications.
Having concurrent OVE or OVH at the time of mastectomy was protective.
The overall rate of complications was 17%.
187
In a study by Villedieu 2021 in JAVMA, the odds of a dog having pulmonary nodules at the time of initial presentation for cutaneous soft tissue sarcoma were increased by which 2 factors?
Grade 3 tumours and presence for longer than 3 months associated with odds of pulmonary nodules.
38% of grade 3 STS had nodules at the time of presentation (compared to 6% for both grade 1 and 2)
188
In a study by Cockburn 2022 in JAVMA, was marginal excision of mast cell tumours associated with a higher risk of wound related complications than soft tissue sarcomas?
No difference between groups.
Use of a subdermal plexus flap increased the risk of complications and delayed healing in both groups.
189
In a study by Iodence 2022 in JAVMA, what was the factor associated with increased risk for incisional complications following MCT or STS excision?
Chemotherapy within 30 days post-operative.
190
In a study by Santoro 2022 in JAVMA, what regional anesthesia technique was associated with improved recovery and pain scores following unilateral radical mastectomy?
Thoracic paravertebral block
191
In a study by Feng 2023 in JAVMA, what was the overall median survival time for patients undergoing radiotherapy for infiltrative lipoma with either microscopic or gross disease?
4.8 years (no difference between microscopic or gross disease).
192
In a study by Murphy 2023 in JAVMA, were incidental or non-incidentally diagnosed canine mammary neoplasms more likely to be malignant? What 2 other factors increased the likelihood of malignancy?
Non-incidentally diagnosed mammary neoplasia was 6 times more likely to be malignant (70% benign, 30% malignant, compared to 93% benign for incidentally diagnosed tumours).
Increasing body weight, and tumour size >3cm also increased the chances of malignant neoplasia.
193
In a study by Rigas 2020 in JSAP, what was the prognosis for patients <12 months of age diagnosed with cutaneous or SQ mast cell tumours?
Prognosis appears better than in adult patients. No recurrence/all patients alive at a median of 1115 days of follow-up.
194
In a study by Reck 2021 in JSAP what was the MST for cats with melanomas of the nasal planum?
265 days (in some cases benign lesions underwent malignant transformation and wide surgical excision may be preferable in all cases).
195
In a study by Chalfon 2022 in JSAP, for dogs undergoing resection of Kiupel high grade mast cell tumours with overtly metastatic lymph nodes was survival improved with lymphadenectomy?
Yes, MST without lymphadenectomy was 250 days compared to 371 days with. Lack of lymphadenectomy was also associated with a higher risk of overall tumour and nodal progression.
Tumour size was associated with a higher risk of local tumour recurrence.
196
In a study by Kim 2022 in JSAP, what were the five most common skin masses in dogs <12 months of age? What percentage of neoplastic skin lesions were benign?
Histiocytoma, papilloma, dermoid cyst, follicular cyst, mast cell tumour.
Males were predisposed to histiocytoma and mast cell tumours. Boxers were predisposed to dermoid and follicular cysts.
99% of neoplastic lesions were benign.
197
In a study by Pickard Price 2023 in JSAP what risk factors were identified for development of mammary tumours in cats? What was the MST?
Increasing age and purebred cats higher risk. Interestingly no effect of neuter status, however age at neuter could not be determined from the records based on the study.
The overall MST reported was 18 months.
198
In a study by Soultani 2021 in VRU, during sentinel lymph node mapping for canine mammary tumours using contrast enhanced CT what findings were correlated with an increased risk of SNL metastatic disease?
Increased median and maximum density Hounsfield units.
199
In a study by Farmer 2022 in VRU, what was the clinical utility of CT for surgical planning of subcutaneous, intermuscular and intramuscular mast cell tumours in dogs?
In a similar study by Gianni 2024 in VRU what was the accuracy of CT in differentiating subcutaneous from cutaneous mast cell tumours? In what percentage of cases was the SNL different from the regional lymph node on CT lymphography?
Insufficient for surgical planning in the majority of cases.
Sensitivity/specificity for differentiating SC from inter or intramuscular tumours was only 85% and 56%.
The accuracy of CT in differentiating subcutaneous and cutaneous mast cell tumours was 57%.
In 32% of cases the SNL did not correspond to the regional LN (successful identification of SNL in 97% of cases with lymphography).
Additional MCT were identified in 32% of dogs with CT.
200
According to O'Toole 2022 in VRU, what benign diagnosis should not be excluded in cases of an osteolytic subungual mass?
Keratoacanthoma
In a similar study by Toshima 2022 in VRU the changes associated with subungual keratoacanthoma were resportion of the P3 ungual process, expansile changes of the ungual crest, and nail enlargement and deformation.
201
In a study by Cecco 2022 in JFMS, where were the majority of feline giant cell neoplasms located? Were males or females overrepresented?
Most were located on the flank, lateral thorax, limbs and interscapular (consistent with injections sites [giant cell neoplasms are thought to be a histologic variant of FISS]).
Females are overrepresented.
202
In a study by Petrucci 2022 in JFMS examining cats with stage IV metastatic mammary carcinoma, what was the overall mean survival? What 2 factors decreased survival?
44 days.
Survival was decreased by the presence of clinical signs and pleural effusion.
Treatment with maximum dose chemo, metronomic chemo, and toceranib phosphate resulted in median survival times of 58, 75 and 63 days, and toxicity in 67%, 20%, and 30% of cases respectively.
203
In a study by Zajc 2022 in JFMS, what was the progression free interval for cats with non-injection site sarcomas treated with adjuvant radiotherapy following incomplete or narrow excision? What was the recurrence rate?
Progression free interval of 2748 days.
Recurrence occurred in 44% of cats. In cases with recurrence the PFI was 164 days.
204
In a study by Arz 2023 in JFMS, what percentage of cats with low grade cutaneous mast cell tumours had nodal metastasis?
59%
205
In a study by Mason 2021 in JVIM , what percentage of dogs undergoing radiation therapy following surgical excision of mast cell tumours developed recurrence? What percentage of subcutaneous mast cell tumours recurred?
7% of patients developed recurrence at a median of 526 days.
No subcutaneous mast cell tumours developed recurrence.
