Chapter 82 Specific Disorders of the Skin and SC Tissues Flashcards
1
Q
What proportion of skin tumours are malignant in dogs?
And in cats?
A
21-37% malignant in dogs
60-65% malignant in cats
2
Q
Whar are the definititions of
Incomplete margins
Close/narrow margins
Complete margins
A
Incomplete margins: neoplastic cells continuous with surgical margin
Close/narrow margins: neoplastic cells <3mm from surgical margin
Complete margins: neoplastic cels at least 3-5mm from surgical margin (depending on tumour type)
3
Q
In what tumour types has FNA needle tract seeding been described in dogs?
A
TCC, pulmonary adenocarcinoma
4
Q
Following surgical excision, what time interval is recommended before adjuvant radiation?
And vice versa re neoadjuvant radiation follwed by surgery?
A
1-3 weeks
wait 3-4 weeks beofre sx
5
Q
List 4 tumour related factors that may cause complicated wound healing
A
- Residual tumour cells
- Tumour related cytokines/bioactive substances
- Cancer cachexia
- Paraneoplastic syndromes
6
Q
What are the four tumour tissue origin types?
A
- Epithelial
- Mesenchymal
- Round cell
- Melanocytic
7
Q
What is the WHO TNM classification for skin tumours
A
8
Q
What tumour parameteres shoudl be described/assessed
A
- Size
- Location
- Consistency
- Colour
- Fixation
- Ulceration
- Signs of inflammation
9
Q
What is the accuracy of FNA for skin masses (cf histo)
A
90%
10
Q
Wat is the typical route of metastasis for
Epithelial tumours
Mesenchymal tumours
A
Epithelial via lymphatics, mesenchymal via blood (e.g. most commom mets for STS are lung)
11
Q
What are the two major functions of lymphatic system?
A
transport and immune reponse
12
Q
What cell types predominate in the cortex, paracortex and medulla of lymph nodes?
A
Cortex: B-lymphocytes (and T-lymphoctes peripherally if antigenically challenged)
Paracortex: T-cells and macrophages (antigen presenting cells)
Medulla: Cords of lymphocytes, macrophages and plasma cells
Schematic representation of a lymph node. The left side illustrates how lymph enters through lymph vessels into the lymphatic sinuses to be drained centrally to the medulla, where it exits through efferent lymph vessels. The right side shows the vascular structures inside the lymph node.
13
Q
In what cancer types is LN metastasis predicitive of prognosis?
A
canine mammary tumours, MCTs, SI tumours, canine primary lung tumours (+- more but these mentioned)
14
Q
3 potential benefits of lymphdenectomy
A
- Removal of potential source of further spread
- Reduce signs of paraneoplastic disease
- Palliation of signs due to enlarged LNs
15
Q
What is the cause of lymhangitis?
An tx?
A
Usually infectious agents
Warm, moist compress + anti-microbial if indicated
16
Q
What si the defnition of lymphoedema?
What causes lymphoedema?
What is the unusual, malignant transormation?
A
Reduced lymphatic transport capacity
Canbe primary (congenital malformations) or secondary (aquired disorders/iatrogenic damage e.g. neoplasia, trauma, radiation, parasitic infection, chronic lymphangitis)
Lymphangiosarcoma
17
Q
How is lymphoedema diagnosed?
What is the treatment for lymphoedema?
A
- Hx + c/s.
- Rule out causes of high lymphatic load (e.g. cardiac dysfuntion, high venour pressure, hypoproteinaemia)
- Lymphangiography or lymphoscintigraphy (delayed, asymmetric or absent visualisation of local LNs/lymphatic channels, collateral channels,visualisation of LNs in deep system, backflow)
- Tx: Physio, compression garments, “coumarin” (=benzypyrones) (–> increased local proteolysis by cutaneous macrophages). NOT diuretics as not a primary water retention problem
18
Q
Describe simple lymphography method:
A
sterile 5% patent blue injection sc between digits of affected limb.
Diffuse distribution = absence of intact lymphatic transport
19
Q
What are the 3 most common skin tumours in dogs?
And in cats?
A
Dogs:
- MCT
- STS
- Perianal gland adenocarcinoma
Cats:
- SCC
- Basal cell tumour
- MCT
20
Q
What is predisposin gfactor for SCC in cats? What does it cause?
A
UV light –> p53 tumour supressor gene mutation
(and possibly papilloma virus but not definitive)
21
Q
What skin conditions are often pre-cursors to SCC in cats
A
Actinic keratosis
Bowenoid in situ carcinoma in cats
22
Q
What is the risk factors of SCC in white cats vs pigmented?
A
x13 risk in white cats
23
Q
List 7 treatment modalities for SCC
A
- Surgery (recommend 5mm margins in feline, 2cm if canine. Mohs micrographic surgery if wide margins not possible)
- Chemotherapy (not recommended as monotherapy. High cox-2 expression in dogs, not in cats)
- Radiation
- Cryosurgery (means no histo…recommend for <5mm superficial lesions only)
- Plesiotherapy (= form of brachytherapy applied to the outside of body. Using strontium (90Sr))
- Photodynamic therapy (=light sensitive drugs + laser e.g. 5-amino-levulinic acid, meta-chlorin, pyropheophorbide-α-hexyl ether. Efficacy decreases quickly with inrceasing lesion depth)
- Immunomodulatory therapy (further research nec.)
24
Q
What is noteworthy re basal cell cytology?
A
May seem poorly differentiated and can be mistaken for other tumours. May have high mitotic rat ebuut behave in benign fashion.
25
List 4 types of sebaceous gland tomour
* Sebaceous adenoma
* Sebaceous adenocarcinoma
* Sebaceous hyperplasia
* Sebaceous epithelioma
26
Sweat gland tumours may originate form which types of gland?
Apocrine and eccrine
Apocrine glands are widely distributed in dogs and cats, always associated with haired skin. Eccrine sweat glands, however, are present primarily in the non-haired skin of the footpads and nose.
27
What is the typical signalment for perianal hepatiod *adenomas* (modified sebaceous glands situated indermis of anus, tail base, prepuce - N.B. not present in cats!)
Tx?
Male *entire*, Cockers: primarily sex hormone dependent tumours (either stimulated by androgens of supressed by oestrogen)
Tx: Castration. Otherwise resection
28
In AGAAS, what is metastatic rate?
And percetnage with paraneoplastic hypercalcaemia (is a negative prognostic indicator)?
Mets in 36-96%
Hypercalcaemia in 27-53% (n.b. post-op hypocalcaemia reported - liekly due to long term supression of parathyroid glands)
29
For AGAAS, what are 3 negative prognositc factors? and 2 positive
_Negative prognostic factors:_
* Stage
* Hypercalcaemia
* Lack of therapy
_Positive prognostic factors:_
* Surgery
* Lymphadenectomy
30
What was MST for AGAAS after various treatments?
What combo of tx reasulted in longest MST?
How does prognosis of cats compare?
16-18 months
Surgery, radiation, mitoxantronechemo (32 mo MST)
Few reports but poor prognosis in cats. MST 3mo
31
Which 6 tumour types make up the STS group
* Fibrosarcoma
* Liposarcoma
* Myxosarcoma
* Undifferentated sarcom
* PNST (inc schwannoma, neurofibrosarcoma)
* Perivascular wall tumour
32
What is the WHO TNM staging scheme for STSs?
33
What is the accuracy of FNA for STSs (vs histo)
63-69% do not exfoliate well
34
What is the overall average metastasis rate for STSs?
What about individually for
Grade 1
Grade 2
Grade 3
**Overall** 6-17%
**Grade 1** \<13%
**Grade 2** \<13%
**Grade 3** 41-44%
35
In STSs, what is the most important factor for local recurrence
Clean surgical margins
therefore recommend 2-3cm margins and a fascial plane
36
What is the MST for STS undergoing surgery, vs surgery and radiation?
Surgery alone 1400d (grade 3 230 - 850d)
Surgery + radiation 2270d
37
How does chemo fit into STS treatment?
Recommended for grade 3 as high rate of metastasis
38
What is noteworthy re canine oral fibrosarcomas
*Biologically high grade, histologically low grade* type!
39
What is the tissue of origin of perivascular wall tumours?
How does perivascular wall tumour metastasis compare with overall STS metastasis rate?
Cellular components of vascular wall except endothelial cells
0-2% so less than average for STS (6-17%)
40
What tissue type do PNST arise from?
Schwann cells or perineural fibroblasts (or both)
41
What 3 IHC stains can be used to identify PNST
* S-100
* Vimentin (only one consistently seen)
* Glial fibrillary acidic protein
42
FISS related to administration of inactivated vaccines. What is the proportional risk of FISS after rabies vacc?
and FeLV vacc?
What other injections have been associated?
x2 for rabies vacc
x5 for FeLV
Also assoc with long acting penicillin, methylpred, cisplatin, melox, microchip, non-absorbable suture, skin staple, sc fluid port, retained swab.
43
How does FISS presentation differ from other STS?
A factor to bear inmind during work up.
What factor was associated wth shorter time to recurrence following sx?
FISS cats younger (8 yr, vs 11 for other STS)
Usually higher histologic grade (up to 70% grade 3)
Forelimb extended and *caudally* may improve evaluation.
* Sx performed by GP (66d recurrence) vs specialist (270d recurrence)
* Expression of aberrant cytoplasmic p53 expression
44
What was MST for cats undergoing radical (5cm) excision of FISS, with and without metastasis
What chemo woul you use?
With mets 388d
Without mets 1500d
Chemo = doxorubicin, or electrochemotherapy using bleomycin
45
What are the recommendations for excision in masses in cats thought to be risk for FISS - When is surgery indicated?
Sx if:
* present \>3 months
* significant size increase within 4 weeks
* \>2cm
46
What is the usual signalment for infiltrative lipoma?
How is dx reached?
What is recurrence rate?
Female, labrador
dx by histo *including* surrounding infiltrated tissue
Recurrence 36-50%
47
What is seen on cytology of liposarcoma?
What was MST with wide excision?
Very cellular, cells contain smal lipid vaculoles that stain strongly with 'oil red O"
MST with wide excision 1200d (600 marginal, 180d intralesional)
48
What proportion of feline haemagiosarcomas are cutaneous?
Asscociated with what ?environmental factor?
50-75% i.e. majority are cutaneous in cats
Assoc with UV light exposure
49
How are canine cutaneous haemangiosarcomas staged?
What is overall metastatic rates?
How does this compare with feline cutaneous haemangiosarc
Stage 1: confined to dermis (2 year MST)
Stage 2: extending i nto sc tissue
Stage 3: invading muscle/fascia (\<1 year MST)
Mets in 30-60% (depending on stage)
Feline MST after complete excision 1500d
50
What is typical hx/signalment of feline fibropapilloma cats (i.e feline sarcoids)
Young (\<5 yr), barn cats with exposure to cattle. Usually on face
51
How many mammary glands do dogs have?
And cats?
Dogs 5 pairs (cr and cd thoracic, cr and cd abdominal and inguinal)
Cats 4 pairs
52
What is the blood supply to mammary glands?
* Lateral and internal thoracic arteries (--\> cranial superficial epigastric)
* External pudendal arteries (--\> caudal superficial epigastric)
53
What is the typical lymphatic drainage of canine mammary glands?
And cats?
Glands 1 and 2 to axillary (can be superficial cervical and sternal)
Glands 3 and 4: axillary or inguinal (sometimes medial iliac and popliteal)
Gland 5: inguinal, medial iliac (sometimes popliteal).
Most cranial gland drains into axillary in cats, rest inguinal (gland 2 may be axillary also)
54
How do mammary lymphatic communications differ in dogs and cats
Contralateral and ipsilateral anasomoses present in dogs, not in cats
55
What dog breed is predisposed to malignant mammary tumours?
GSD
56
What is the risk for benign canine mammary tumours vs malignant?
x2-5 more likely benign
57
Respective of the risk in entire females what is the risk of developing mamary tumours in dogs spayed:
Before 1st oestrus
Before 2nd oestrus
After 2nd oestrus but \<2 years old
**Before 1st oestrus** 0.5%
**Before 2nd oestrus** 8%
**After 2nd oestrus but \<2 years old** 26%
Obesity before 1year also risk factor for mammary tumours
58
How does oestrogen and progesterone receptor expression differ between benign and malignant tumours?
expressed in \>90% benign tumours, approx 50% of malignant (inc oestrogen receptors correlated with lower ki-67 proliferation marker i.e. lose hormane receptor expression as become more malignant
59
List 4 genes associated with mammary tumorigenesis
* c-erbB-2
* p53
* BRCA1 and BRCA2
* RAD51
60
How does cox-2 expression differ between banign and malignant mammary tumours
Higher in mammary tumours
61
Describe WHO TNM classification for canine mammary tumours
62
List 3 specific sub types of malignant, benign and unclassified canine mammary tumours
63
What percentage of canien mammary tumours are inflammatory carcinoma?
What glands are most commonly affected?
What is met rate?
What is MST?
8% of mammary tumours
Most commonly glands 4 or 5
Met rate 8-100%
MST 25-60d
64
For canine mammary tumurs, when is each f the following indicated?
Lumpectomy
Simple mastectomy
Regional mastectomy
Chain mastectomy
Lumpectomy: \<0.5cm masses
Simple mastectomy: centrally located mass with 2-3 cm margins
Regional mastectomy: rest
Chain mastectomy: multiple nodules, 3rd gland masses, \>1cm masses with fixation, other suspiscion of malignancy
65
What was recurrency of mammary tumour with lymphatic/vascular invasion on histo?
97%
66
What factors are prognostic in canine mammary masses?
* Histologic type (esp grade and invasiveness, proliferation markers ki-67 and AgNORs)
* Tumour size
* LN metastasis
Chemo improved survival
67
What % of mammary tumours in cats are malignant?
What is met percentage?
85%
80% met (at necropsy)
68
What proliferatioon markers are negatively associated with survival in feline mammary tumours?
HER-2
Ki-67
VEGF
69
What is the name of the hormonally driven condition causing massive enlargement of feline mammary glands (think case we saw at RSPCA)
What is tx?
Fibroadenomatous hyperplasia, usually cats \<2 years old
Tx = remove hormonal influence i.e. spay (progesterone blocking drug aglepristone --\> full remisison but abortion)
70
What is MST for feline mammary tumours?
4mo - \>3 years (depending on tumour size, presence of mets).
N.B. chemo not shown to be beneficial. Radiation not investigated
71
What are the precursor cells for mast cells?
CD34+ progenitor cells in bone marrow
72
What do mast cell granules stain with?
Cationic dyes
73
which 2 breeds represent majority of MCT cases?
Boxer + Boston terrier
74
List 5 extra-cutaneous MCT sites
* Conjunctiva
* Trachea
* Oral cavity
* Salivary gland
* Larynx
* Nasopharynx
* GI tract
* Ureter
* Spine
* (Viceral/systemic mastocytosis)
75
What two tumours does cd117 stain for?
MCT and GIST
76
What is the name of this sgn re MCTs:
Darier sign = oedema, erythema, inflammation
77
What is the order of metastasis in MCTs
Local Ln --\> liver and spleen
78
Briefly explain the two grading systems for MCT
_Patnaik_
* Grade 1 (differentiated) , 2 (intermediate) or 3 (undifferentiated).
3 downsides to Patnaik (--\> alternative scheme):
1. Assumes tumour is originating in dermis
2. Doesnt account for v variable behaviour of grade 2 tumours
3. Inconsistent grading re 1 vs 2 among pathologists.
_Kiupel_
Low vs high grade
79
What % MCTs can be diagnosed vis FNA with use of stains?
What type of stains?
96%
Romanovsky type stains (includes diff-quik)
80
In canine MCT, list 5 factors associated with survival
* LN metastasis
* Mitotic index
* Special stains (ki-67, AgNORs, PCNA)
* Kiupel grade
* Patnaik grade
* Mucous membrane location (except conjunctiva!)
* Darier sign/systemic signs
* Location (prepucial and scrotal + care re perineal/inguinal)
81
Mast cells are present in normal LNs. List 3 factors that would be considered as neoplastic population
* Clusters/sheets
* Increased numbers in \>2 hpf
* Large number of atypical mast cells
82
What is the MST for low vs high grade canine MCTs?
Low grade 2-4 years
High grade 100-200d
83
Breifly outline MCT tumour tx:
* Sx with 2-3cm margins + 1 fascial plane + metastatic LN excision
* If incomplete margins ideally re-cut (most effective), otherwise radiation
* Consider chemo in grade 3 and high risk grade 2
84
What is the initial chemo choice in MCTs?
Lomustine
85
Aside form chemo and radiation, list 2 other adjuctive methods used for MCT tx
Electrochemotherpay
Hypotonic shock
86
List the two ytological types of feline MCT and typical presentation.
Mastocytic MCT (differentiated vs poorly differentiated)
Histiocytic MCT (Siamese cats, 2-3 years old), regress without tx
87
Aside form cutaneois list 2 feline MCT sites + MST with tx
Spleen. Splenectomy --\> MST 12-20 months
GIT. MST 2 months (but longer reported)
88
What are the three most common GIT tumours in cats?
1. Lymphoma
2. Adenocarcinoma
3. MCT
89
Is MCT grade prognostic in cats?
No
Mitotic index most effective prognostic factor
90
What cells cause histiocytomas?
Tx?
Langerhans cells
No tx necessary, usually regress. Steroids contraindicated (because regression is characterised by lymphocyte infiltration)
91
What is IHC stain for histiocytic tumours?
What is first line chemo agent?
CD18
Lomustine
92
What haematological change may be seen with extramedullay plasmacytoma?
Monoclonal gammopathy
93
What is noteable re TVT genetic makeup
TVT tumour karyotype has 59 chromosomes (dogs have 78)
94
What is TVT tx
Vinccristine, weekly, 0.5 - 0.75 mg/m2
95
What are 5 most common oral tumours in dogs:
And 3 most common in cats
_Dogs:_
1. Malignant melanoma
2. SCC
3. Fibrosarcoma
4. /5. Osteosarc, acanthomatous ameloblastoma
_Cats:_
1. SCC
2. Fibrosarc
3. Malignant melanoma
96
What IHC stains are used for amelanocyic melanoma?
S-100 and NSE
97
How does malanocytic tumour type differ with location.
Pigmented skin mainly benign, oral cavity and nail ned more commonly malignant
malignany: Ocular \> oral cavity \> nail bed \> skin
98
Adjunct therapy advice for malignant melanoma?
Systemic tx warranted given high met rate
(chemo, immune modulators)
99
List immune modulators developed for use in malignant melanoma
"Melanoma vaccines"
* Human tyrosinase DNA vaccine (also reported safe (?effective) in cats)
* Human CSPG4-DNA vaccine (Chondroitin-sulphate proteoglycan 4 is a tumour progression marker. Highly expressed in 60% of canine melanomas)
* Local suicide gene therapy + cytokine enhanced tumour vaccine (6 and 9 year MST not reached in dogs with surgery followed by this!! vs 100d with sx only)
100
What are 5 most common canine nail bed tumours?
1. SCC
2. Malignant melanoma
3. STS
4. MCT
5. Osteosarc
101
What is the metastatic rate of canine nail bed tumours
low, 5-29%
| (worse for melanoma, 40-60%)
102
What is the MST for canine toe osteosarc?
over 2 years reported
103
What are the three most common nail bed tumours in cats (no order)?
SCC, fibrosarcoma or metastatic (bronchiolar adenocarcinoma, SCC, Apocrine gland adenocarcinoma)
Lung digit syndrome often affects several digits so x-ray all.
104
There are 4 main digital arteries - name them
Axial and abaxial dorsal arteries and palmar proper arteries.
105
What is a pilonidal sinus?
How to work up?
When is sx indicated?
* Incomplete separation of ectodermal and neural tissue during embryogenesis (a tubular skin structure that extends from skin to underlying ST). Extensive ones communicate with spinal dura mater. Lined by skin (i.e. squamous epithelium). Usually cervical or cranial thoracic (LS and sacrococcygeal noted).
* Advanced imaging to assess spinal involvement
* Sx if chronic derm signs or neuro signs (may require DSP excison, or if attached to dura dorsal laminectomy and dura mater resection)
106
What is this?
How is it managed?
Nasal dermoid cyst
During embryologic development, a canal called the foramen cecum develops in the frontal bone and allows an outpouching of meninges into the prenasal space and into contact with somatic ectoderm. With maturation the canal normally closes. Persistence of the canal results in a draining sinus in the dorsal midline of the nasal bone that perforates through an incomplete suture line in the nasal septum. Communication with the meninges has been reported in humans but not in dogs. Clinical signs of nasal dermoid sinus cysts include drainage and crusting around the affected area. Obstructed sinuses may result in perisinus swelling, abscessation, and infection. Treatment is surgical resection, including the affected portion of the nasal septum in some cases. Resection is facilitated by catheterization of the sinus
107
What infectious agents have been associated with aquired sinus tracts due to primary infection?
* *Nocardia*
* *Sporothrix*
* Botryomycosis
* *Mycobacterium*
* *Pythium*
108
What is the sens/spec of positive contrast sinography (fistulography) for ID of FBs
In what % of cases was US able to identify FB
Sensitivity 87%
Specificity 100%
82% i.e. fistulography better
