Approach to Skin Tumours Flashcards
1
Q
what is the clinical approach to skin tumours and history considerations (6)
A
- age
- breed
- sex
- duration of lesion(s)
- progression of lesion(s)
- other clinical signs
2
Q
how would you clinically examine skin tumours (5)
A
- site: depth
- site: locaiton
- size: measure
- ulceration
- mobility
3
Q
how does the depth affect the approach to skin tumours
A
dermal, subcutaneous –> affects grading of mast cell tumours
deep soft tissues, bone (soft tissue sarcomas, osteosarcomas)
4
Q
how does the location affect skin tumours
A
location can affect behaviour/malignancy for some tumour types (melanoma, mast cell tumours)
-mucocutaneous, back, digit
5
Q
how are skin tumours diagnosed
A
cytology useful for some tumour types
histopathology for definitive diagnosis
6
Q
what are ddx for skin tumours (4)
A
- hyperplastic conditions
- granulomatous conditions
- immune mediated conditions
- developmental lesions
7
Q
how are skin tumours staged
A
TNM
T - primary lesion (extent)
N - local & regional node palpate, image, aspirate
M - distant metastasis, Xray, bloods
8
Q
how are skin tumours treated
A
Local disease: surgery (radiotherapy)
Local & regional LN: surgery +/- radiotherapy
Multifocal/diffuse: chemotherapy
9
Q
what are mutliple skin lesions
A
metastases from any malignant tumour
10
Q
what are examples of multiple skin lesions (3)
A
- primary cutaneous lymphoma (T cell)
- disseminated mast cell tumours
- histiocytic skin conditions
11
Q
what are examples of primary cutaneous lymphomas (2)
A
- primary cutaneous LSA - dermal/non-epitheliotropic
- mycosis fungoides - epitheliotropic (epiderma)
12
Q
what are histiocytic skin conditions (2)
A
- reactive/immune mediated =
- cutaneous histiocytosis
- systemic histiocytosis - malignant =
- histiocytic sarcoma (malignant histiocytosis)
- hemophagocytic histiocytic sarcoma
13
Q
what are benign histiocytic skin conditions
A
cutaneous histiocytoma (solitary)
14
Q
what is cutaneous histiocytosis
A
reactive histiocytosis
skin only
diffuse/nodular infiltration with myeloid interstitial dendritic cells of dermis and subcutis
15
Q
what is systemic histiocytosis
A
reactive histiocytosis
skin, lymph nodes and other organs (BMD, rottweiler, retrievers)
diffuse/nodular infiltration with myeloid interstitial dendritic cells of dermis and subcutis
16
Q
what are the clinical features of reactive histiocytosis
A
lesions wax and wane but over time slowly progressive
underlying disorder of immune regulation
17
Q
how would you treat reactive histiocytosis
A
some may respond to immunosuppressive drugs (high dose corticosteroids, cyclosporine, tetracycline/niacinamide)
18
Q
what lesion is shown here
A
reactive histiocytosis
cutaneous
19
Q
what lesion is shown here
A
reactive histiocytosis
20
Q
what is a histiocytic sarcoma
A
high grade sarcoma
localized and disseminated forms (malignant histiocytosis)
21
Q
what breeds are predisposed to histiocytic sarcomas
A
BMD
flat coated retriever
rottweilers
golden retrievers
22
Q
what are histiocytic sarcomas derived from
A
myeloid intersitital dendritic cell staining with CD1, CD11c, MHC II, CD18, Iba-1
23
Q
what are solitary epithelial/epidermal skin tumours (3)
A
- papilloma
- basal cell tumour (trichoblastoma or solid cystic ductular sweat gland adenoma)
- squamous cell carcinoma
24
Q
what are solitary adnexal/derma skin tumours (2)
A
- sebaceous and sweat gland adenoma/ACA
- hair follicle tumours (pilomatricoma/trichoepithelioma/trichoblastoma)
25
what are solitary mesenchymal/subcutaneous connective tissue skin tumours (2)
1. fibrous tissue (fibroma/sarcoma)
2. adipose tissue (lipoma/sarcoma)
26
what are melanocytic solitary skin tumours
melanoma
27
what are solitary mast cell skin tumours
mast cell tumours
28
what are other examples of solitary skin tumours
histiocytoma
plasmacytoma
29
what are papillomas in young dogs and cats
papilloma viral induced
often multiple should resolve spontaneously (more common in mouth in dogs)
30
what are papillomas in old dogs often confused with
sebaceous adenoma
31
are basal cell tumours/carcinomas more common in dogs and cats
cats
less so in dogs
32
what are basal cell tumours/carcinomas reclassified as
trichoblastoma or solid cystic apocrine ductal adenoma
33
what is the signalment of basal cell tumours/carcinomas
middle age to old cats
34
what is the appearance of basal cell tumour/carcinomas
solitary, discrete, well circumscribed, can be pigmented
35
are basal cell tumour/carcinomas slow or fast growing and are they benign or malignant
slow growing
bengin
36
how are basal cell tumour/carcinoma
surgical cure with wide local excision
rarely metastasis
37
what are the causes of sqaumous cell carcinomas
chronic exposure to UV light in depigmented skin (white) areas
38
what is shown here
papilloma
39
what lesion is shown here
basal cell tumour/carcinoma
40
what is shown here
squamous cell carcinoma
41
how are SCC treated
locally invasive
metastasis via lymphatics but variable -- often slow
treatment wide local surgical resection
42
what are the differences of squamous cell carcinomas in the nasal planum
cats: solar induced, superficial or invasive
dog: not solar induced, usually very invasive and aggressive
43
how is SCC of the nasal planum treated
surgical excision (nosectomy)
radiotherapy (external beam)
brachytherapy (strontium 90)
photodynamic therapy
electrochemotherapy
curettage and diathermy
44
what are the SCC of the foot in cats and dogs (4)
1. ditial/interdigital SCC: aggressive
2. subungual SCC
3. syndrome of multiple SCC of digits (dogs 3% of SCC)
4. syndrome of metastasis from lung carcinoma in cats (lung digit syndrome)
45
what breeds are predisposed to SCC of the digit
black coat large breeds
lab
standard poodle
schnauzer
rottweiler
gordon setter
flat coated retriever
46
what are the features of invasiveness of SCC of the digit
locally invasive
bone destruction (subungual less metastatic than digit SCC?)
47
how are SCC of the digit treated
amputation at metacarpophalangeal or proximal interphalangeal level
radiotherapy?
48
what are other digit tumours besides SCC (4)
1. melanoma
2. soft tissue sarcoma
3. mast cell tumour
4. osteosarcoma
49
what are benign adnexal sebaceous gland tumours
hyperplasia -- warts, cysts, adenoma, epithelioma
most common skin tumour of old dogs
50
what breeds are prediposed to sebaceous gland tumours
cocker spaniel
poodle
51
what are hair follicle tumours (4)
1. pilomatricoma
2. trichoepithelioma
3. trichoblastoma (prev called basal tumours)
4. meibomian gland adenoma
52
what are malignant adnexal tumours (2)
1. matrical carcinomas
2. malignant sweat/sebaceous carcinomas
53
what are matrical carcinomas
adnexal malignant pilomatricoma/trichoepithelioma
54
how are adnexal tumours treated
very aggressive tumours
surgery/radiotherapy/chemo?
55
what is shown here
sweat gland adnexal carcinoma
56
where are peri-anal adenomas derived from
skin sebaceous gland
57
what is the signalment of peri anal adenomas usually
elderly male dogs
58
describe the appearance of peri anal adenomas
solitary, discrete, button like lesion in perianal skin
can get big and ulcerate
can also be found at base of tail, prepuce and midline
59
are peri anal adenomas benign or malignant
usually benign, hormonally dependent
60
how are peri anal adenomas treated
usually regress with castration but surgical excision may be needed
but sometimes can transform into adenocarcinoma
61
what are malignant peri anal tumours (2)
1. perianal adenocarcinoma (sebaceous glands)
2. anal sac adenocarcinoma (apocrine gland)
62
how are perianal adenocarcinoma treated
surgery or radiotherapy?
surgery + chemo (carboplatin or mitoxantrone or TKI palladia)
63
what age are canine cutaneous histiocytomas commonly seen
young dogs \<5 years
50% in dogs \<2 years
64
where are canine cutaneous histiocytomas typically seen
head, limbs, feet and trunk
65
are canine cutaneous histiocytomas malignant or benign
rapidly growing intradermal lesion but benign
66
what are canine cutaneous histiocytomas derived from
langerhans cell derived
67
how are canine cutaneous histiocytomas treated
will regress if left alone
surgery curative
68
what breeds of dogs are cutaneous melanocytic tumours seen in
scotties
boston terrier
airedale
cocker spaniel
69
describe the apperance of cutaneous melanocytic tumours
solitary, dermal, dark mass
can be amelanotic, ulcerated especially if malignant
70
are cutaneous melanocytic tumours typically benign or malignant
85% are slow growing and benign
71
how are cutaneous melanocytic tumours treated
wide surgical excision curative
72
what is the prognosis of cutaneous melanocytic tumours
good prognosis
73
which melanocytic tumours have good prognosis
cutaneous
74
which melanocytic tumours have a bad prognosis
mucocutaneous (oral, anal) and digital (not eyelid)
75
what lesion is shown here
peri anal adenoma (hepatoid)
76
what is shown here
perianal adenocarcinoma
77
what is shown here
anal sac adenocarcinoma
78
what is shown here
canine cutaneous histiocytoma
79
what is shown here
cutaneous melanocytic tumour
80
what is shown here
mucocutaneous melanocytic tumour
oral melanoma
81
describe the rate of metastasis of mucocutaneous melanocytic tumours
rapid
82
how are oral melanomas treated
wide excision or radiotherapy give good local control
metastasis --\> no chemo works well (carboplatin/TKI?)
DNA vaccine -- oncept for minimal residual disease
83
what type of MCT are most common in the dog
skin
84
what are type of MCT are most common in the cat
visceral
85
what is the appearance of MCT in the dog
skin
often solitary tumours but can be multiple
86
what is the appearance of visceral MCT in the cat
1. splenomegaly
2. hepatomegaly
3. mesenteric lymphadenopathy
4. GI mass
5. BM/blood
6. often preceeded by primary skin undifferentated MCT (dog)
87
what is the signalment of skin MCT in the dog
middle aged to older dogs
occasionally seen in puppies
no sex predisposition
88
what breed of dog are predisposed to skin MCT (6)
1. boxers\*
2. staff BTs
3. labs\*
4. golden retrievers\*
5. weimeraners
6. pugs
\*often multiple unrelated tumours
89
what are MCT very variable with respect to (3)
1. apperance
2. behaviour/metastasis (LNs/abdominal organs)
3. response to treatment
90
what are proliferation markers of MCTs (4)
1. mitotic index
2. Ki67
3. AnNOR count
4. cKIT
91
what are mitotic index markers used in MCT
of mitoses/10 HPF
\>5 mitoses/10HPF has worse prognosis
92
what is Ki67 marker of proliferation of MCT
nuclear stain for cells in cell cycle
\>1.8% of positive nuclei/total mast cells in field has worse prognosis/decreased survival
93
what is AgNOR count in MCT proliferation marker
nuclear silver stain and PCNA (proliferating cell nuclear antigen)
both increased in proliferating cells and associated with worse prognosis but not independent of grade
94
what is cKIT MCT marker
cell surface growth factor receptor with TK enzyme
mutated in 15-40% mast cell tumours -- worse prognosis
mutation detected by PCR test
mutation may mean better response to TKI treatment
protein can be visualized in MCT by IHC, pattern of expression associated with prognosis
95
what is KIT1 pattern of expression in an MCT mean
membranous --\> seen with normal cells or low grade MCT
96
what is KIT2 pattern of expression in an MCT mean
focal cytoplasmic: aberrant --\> worse prognosis
97
what is KIT3 pattern of expression in an MCT mean
diffuse cytoplasmic --\> aberrant
worse prognosis
often high grade tumours
98
what do mast cell tumour granules contain
1. histamine
2. heparin
3. vasoactive amines
99
when do mast cell tumours degranulate
either spontaneously or due to trauma
100
what is shown here
mast cell tumour
with granules
101
what local effects does degranulation of MCT cause (3)
erythema
wheal formation
darier's sign
102
what is shown here
MCT degranulation local effects
103
what is hyperhistaminemia and what causes it
degranulation of MCT
paraneoplastic syndrome --\> systemic effects
104
what systemic effects does hyperhistaminemia cause
acts on H2 receptors in gastric parietal cells, leading to
1. increased acidity and motility
2. vomiting, anorexia, melana
3. gastirc ulceration
plasma histamine increased but plasma gastrin decreased by negative feedback loop from acid
105
how is hyperhistaminemia treated (5)
1. supportive therapy -- fluids
2. H2 antagonists (cimetidine, ranitidine, famotidine)
3. gastric protectants (sucralfate antepsin)
4. proton pump inhibitor (omeprazole)
5. remove/treat mast cell tumour to remove source of histamine
106
what biological effects can MCT have (3)
1. hypotension: histamine + vasoacitve substances
2. coagulation problems (check before surgery!): localized hemorrhage
3. delayed wound healing: proteolytic enzymes + vasoactive amines
107
which MCT cause biological effects?
low grade: may have local effects
high grade: more likely to have systemic effects
high serum histamine reported with all grades
108
how would you approach an MCT
do FNA to confirm diagnosis or biopsy
109
how do you treat clinical stage I MCT (solitary mass and no sentinel LN metastasis)
Surgical excision only — wide local excision or
Marginal excision and radiation
Radiation alone if not amenable to surgery at all
110
how do you treat clinical stage II MCT (solitary mass + sentinel LN metastasis)
Surgical excision of mass and LN
Marginal excision +/- radiation and LN excision/radiation
Metastasis to LN implies higher grade so chemotherapy as well
111
what will help you decide if chemotherapy is indicated in MCT
histopathology and the grade of the tumour
112
how would you treat low grade/grade I + low grade/grade II MCT
**Wide local excision should have been sufficient to remove all tumour cells**
**Check histological margins are adequate — if incomplete, consider repeat surgery or if not possible use radiation**
**If radiation not available, consider chemotherapy/TKIs for local control but only if signs of malignancy**
-PNS signs/bruising, sentinel LN involved, high mitotic rate (\>5 per 10hpf is worse), high Ki67 index (\>1.8 may be worse prognosis), cKit mutation/staining pattern
113
how would you treat high grade/grade II + high grade/grade III MCT
Wide local excision or radical excision will have been needed to remove primary tumour (cytoreductive surgery and radiotherapy if good surgical margins not achieved)
Adjunctive chemotherapy will always be needed because of high risk metastasis (whether detectable or not on staging)
Treatment for paraneoplastic signs if presents
Chemotherapy alone for unresectable gross disease (TKIs licensed for gross disease)
114
when is chemo indicated to treat MCT
Only indicated for management of high grade malignant/metastatic tumours
Usually adjunctive to surgery
115
what is the response of MCT to chemo
esponse of gross disease to MTD chemotherapy:
47% vinblastine + prednisolone
44% lomustine
116
what chemotherapy is used to treat MCT
**2 week Vinblastine/prednisolone protocol**
**Vinblastine 2mg/m^2 IV q 1 week x 4 doses, q2 weeks x 4 doses**
**Prednisolone 1mg/kg PO daily for 2 weeks, 0.5 mg/kg daily for 10 weeks**
OR
**OR single agent Lomustine**
Lomustine at 60-90mg/m^2 PO q3 weeks for 4-6 doses
**OR single agent TK inhibitor (treat cytotoxins)**
Masitinib (Masivet): 10-12.5 mg/kg daily
Toceranib (Palladia): 2.5-3.0 mg/kg EOD
117
what is the signalment of feline MCT
most common skin tumour in cat
older cats (mean age 11 years)
118
what breeds of cats are predisposed to MCT
siamese (burmese, russian blue, ragdoll) predisposed
119
what are the typical features of feline skin MCT
usually solitary and benign
small percentage are malignant and aggressive
120
what would indicate a poorer prognosis of feline skin MCT
\> 5 masses
121
how are skin MCT treated
surgery curative
122
what are the most common histological types of MCT in the cat
mastocytic: most common
atypical
123
what are the types of mastocytic MCT in felines
compact (well differentiated)
or
diffuse (poorly differentiated)
124
what breed are atypical MCT seen in
young siamese \<4 years
125
how are feline MCT graded
no grading system recognized
126
what are histological prognostic indicators of feline MCTs (4)
1. mitotic index may be important (\>3.5 HPF has poor prognosis)
2. mitotic index stronger predictor than Ki67
3. multinucleated giant cells -- poor prognosis
4. mutated cKIT in 2/3 cases
127
what is the behaviour of soft tissue sarcomas primary masses (4)
1. all are locally infiltrative and invasive (usually subcutaneous)
2. beware of pseudocapsule (compression zone)
3. sarcomas DO NOT shell out --\> surgery must be radical
4. possibly can do cytoreductive resection and XRT
128
what are the causes of feline injection site sarcomas
rabies
FeLV injection sites
aluminium adjuvant associated?
129
what are the features of feline injection site sarcomas
very infiltrative and intermediate/high grade
130
how are feline injection site sarcomas treated
use advanced imaging to ensure complete excision
surgery +/- radiotherapy for primary tumour
chemotherapy for metastasis
131
how do soft tissue sarcomas usually metastasize
Via hematogenous route usually (15% overall)
Variable % depending on type and grade
132
how do low grade soft tissue sarcomas metastasize and how are they treated
low risk of metastasis
no chemo needed
133
what are examples of low grade soft tissue sarcomas
Peripheral nerve sheath tumour (PNST)
hemangiopericytoma
134
how do intermediate soft tissue sarcomas metastasize and how are they treated
moderate risk of metastasis
possibly treated with chemo
135
what are examples of intermediate grade soft tissue sarcomas
Fibrosarcoma, myxosarcoma
136
how do high grade soft tissue sarcomas metastasize and how are they treated
high risk
chemo needed
137
what are examples of high grade soft tissue sarcomas
Hemangiosarcoma, FISS, Histiocytic sarcoma
138
how is chemo used to treat sarcomas
as an adjunct to surgery for high grade tumours
## Footnote
High risk of metastasis
139
what chemotherapy is used to treat sarcomas
Doxorubicin based protocol for most sarcomas (ex. HSA) (need care in cats ex. FISS)
Lomustine for histiocytic sarcomas
140
what age are hemangiosarcomas seen in
older dogs and cats (rare)
141
what breeds are predisposed to hemangiosarcomas (3)
GSD
lab
g retriever
142
what are the sites of hemangiosarcomas (5)
1. spleen
2. right atrium
3. pericardium
4. muscle
5. subcutis
143
how do hemangiosarcomas metastasize
via blood, transabdominal seeding (lymph nodes often negative)
144
how do hemangiosarcomas present (4)
1. Superficial/soft tissue mass or hematoma
2. Splenic rupture: hemorrhagic, collapse, abdominal distention, pale mms
3. Cardiac signs: muffled heart sounds, arrhythmias, right sided heart failure
4. Regenerative anemia (blood loss, microangiopathic hemolysis), thrombocytopenia, neutrophilia, DIC
145
how are hemangiosarcomas treated (2)
1. Primary tumour: surgical excision of subcutaneous mass (radical excision/amputation), splenectomy, pericardiectomy
2. Metastasis: Adjunctive chemotherapy (doxorubicin, VAC protocol, metronomic therapy)
146
what is the MST of splenic hemangiosarcomas
Surgery alone 1-3 months
Surgery and chemotherapy 5-7 month
147
what is the MST of intramuscular hemangiosarcomas
6-9 months with chemo
148
what is the MST of skin hemangiosarcomas
Has better prognosis (surgery alone)
Dermal: 26-33 months (UV induced, thin coated dogs like whippets, pit bulls)
Subcutaneous: 7-10 months (39-40 mo in 1 study with adjuvant doxorubicin)
149
what is the MST of cardiac hemangiosarcomas
3-4 months with doxorubicin vs 12 days with no treatment
