Tumors of appendicular and axial skeleton Flashcards Preview

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Flashcards in Tumors of appendicular and axial skeleton Deck (45)
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1
Q

What is the most common primary bone tumor

A

Osteosarcoma

2
Q

OSA signalment

A

Large-Giant breeds
Neutering status!
Bimodal distribution 1-2yr & 7-9yrs
Small dogs - axial skeleton

3
Q

What is the OSA neutering status factor

A

2x risk of OSA in gonadectomized dogs
ROTTIES
intact = protective factor

4
Q

Proposed OSA etiologies

A

Hormones (neutering)
Genetic - rotties, greyhound, danes, s bernard, irish wolfhound
repetitive microtraumas
molecular factors

5
Q

What are some molecular facotrs

A

Overexpressed oncogenes: MET, TrK, HER-2
Abbreant IFG-1
Abberant mTOR signaling
Telomeralse presence

6
Q

OSA presenting complaint

A

lameness - inflammation, micro fractures

Swelling - extra compartmental extension of tumor

7
Q

OSA differntials

A

Chondrosarcomas

Infectious - fungal will have systemic disease

8
Q

Anatomic locations

A
Away form elbow, towards knee
80% in appendicular skelton
forelimbs 2x > hindlimb
*distal radius!
Metaphyseal region
9
Q

OSA dx: CBC / chem

A

elevated ALP = bad

10
Q

OSA dx: locoregion lnn assessment

A

5% incidence = low

11
Q

OSA dx: thoracic met check vs CT

A

90% have micromets at Dx. missed with rads

12
Q

OSA dx: FNA/Cytology

A

85% diagnostic accuracy - preferred over biopsy

13
Q

OSA dx: Biopsy (2)

A

Jam shedi - worse dx, better px

Michele trephine - better dx, worse px (fractures)

14
Q

OSA dx: Radiographic appreance

A
Aggressive bone lesions
lytic, plastic, mixed
codmans triangle
palisading cortical bone
fractures
DONT CROSS JOINTS
15
Q

Codmans triangle

A

periosteal lifting caused by subperiosteal hemorrhage

16
Q

Local control

A

Amputation = gold standard
Limb salvage
Stereotactic radiosurgery

17
Q

Amputation techniques

A

forelimb - forequarter technique (include scapula)

Hindlimb - coxofemoral disarticulation technique/ en bloc acetabulectomy/subtotal hemipelvectomy

18
Q

Amputation results

A

well tolerated.
thoracic - harder balance
pelvic - harder gaining speed

19
Q

Limb salvage indications

A
severe OA
neurological disease
Morbid obesity
OWNER
*distal radius
20
Q

Limb salvage contraindications

A
large lesion
extensive soft tissue involvement
pathology fracture
inappropriate location
noncompliant owner
advanced disease
21
Q

Limb salvage locations

A

distal radius
digit/metacarpus/tarsus
distal ulna
scapula

22
Q

distal radius salvage

A

preferred/most common

reconstruct w. surgical steel

23
Q

Distal ulna salavage

A

ulnectomy.
excision of styloid process
annular ligament reinforcement

24
Q

Limb salvage complications

A

> 50% have complications
implant failure 40%
local reoccurrence
infection >50%, 2/3 dx after 6 months

25
Q

Limb salvage prognosis

A

good-excellent function 80%

26
Q

Why is infection helpful in limb salvage

A

it increases the MST and met free interval y activating the immune system to be hyperactive

27
Q

Stereotactic radiosurgery

A

entire radiation dose delivered in one treatment
min dose = 35Gy
high dose =50-60Gy
proximal humerus is best

28
Q

Systemic therapeutics

A

Adjunct chemo

29
Q

Adjunct chemo options

A

Carboplatin (DOC)
Bisphostphates
Amino-bisphosphates

30
Q

carboplatin

A

monitor CBC

Starting pre, during, post op doesn’t alter efficacy

31
Q

Bisphosphates

A

inhibits osteoclastic bone resolution

32
Q

Amino-bisphosphates

A

Pamidronate

pain palliation 30-50%

33
Q

Palliative therapeutics

A

RT

Analgesia

34
Q

RT

A

50-92% response rate.
but very short duration of response
better response when <50% bone involved and proximal humerus

35
Q

Analgesia

A

every patient should get.

NSAIDs, opioids, NMDA antagonists, anticonvulsants

36
Q

Aratana

A

canine OSA vaccine
indevelopment
attenuated listeria monocytogenes

37
Q

PROGNOSIS (KNOW THIS)

A

palliative analgesia- 1-3m
Surgery - 4-6m
Sx + chemo - 8-12m
Chemo alone - not recommended

38
Q

Prognostic considerations

A
Body weight
age
site
volume
histologic grade
ALP
39
Q

Weight

A

<40kg is positive

40
Q

Age

A

<7yrs and > 10 is positive

41
Q

Site

A

proximal humerus is negative

42
Q

Volume

A

larger is negative

43
Q

Histological grade

A

3 is negative

44
Q

ALP

A

NEGATIVE
preop increase that doesn’t decrease within 40 d
every 100U/L increase is 25% risk of death

45
Q

Feline OSA

A

diaphysis
Pelvic > thoracic
less aggressive, slower growth
amputation may be curative