72. MS neoplasia_Limbspare

Question 1

the most common primary bone tumor in dogs

Answer 1

OSA 85% bone tumors in dogsappendicular vs axial

Question 2

T/Fin Rottweilers, an inverse relationship has been documented with length of gonadal hormonal expression and the risk of developing OSA

Answer 2

TRUEearly OHE/neuter may actually increase risk OSA

Question 3

the biological behavior of axial OSA in dogs is similar to appendicular OSA with the exception of OSA in what location

Answer 3

MANDIBLE OSA

Question 4

difference btwn axial and appendicular OSA

Answer 4

BOTH act similarly (except mandibular OSA)axial die from local disease vs appendicular die from metastatic disease

Question 5

where is the predilection of appendicular OSA

Answer 5

metaphyseal area of long bonesaway from elbowtoward the kneedistal radius and proximal humerus are the two most common sites

Question 6

types of OSA

Answer 6

endosteal (most common–in medullary cavity)periosteal (invades into medullary cavity from outside)parosteal (does not invade underlying cortex)

Question 7

bone biopsy

Answer 7

michelle trephine (larger, more diagnostic, risk fx, single)vs jamshidi (smaller, less risk fx, less diagnostic, multiple)RO sarcoma, other neoplasia, osteomyelitis–bacterial or fungal, bone cystcenter of radiographic abN recommended; caution biopsy tract and do NOT penetrate both corticesaccuracy 80-90%

Question 8

diagnostic accuracy of FNA

Answer 8

FNA overall accuracy 71%up to 92% when a neoplastic lesion was Id’dcan use US guided 20 gauge FNA

Question 9

mets and OSA

Answer 9

need fully screening (rads, bone scintigraphy, CT)rads nodule 7-9 mmCT <3 mmall patients have micro metastasisonly 15% will have macromets at time of diagnosis of appendicular OSAmost common location - other bones, lungs

Question 10

Jankowski et al evaluated 399 dogs with OSA staged with scintigraphy, with what conclusions

Answer 10

8% had evidence of up take on scintigraphy that were highly suspicious of bone mets

Question 11

MST for OSA with or without LN mets following amputation and chemotherapy

Answer 11

with LN mets 60 dayswithout LN mets 320 dayssignificantly shorter with LN mets

Question 12

ALP in OSA prognosis

Answer 12

bALP increase in total ALP and b ALP has been documented indicator of POOR prognosis in dogs with OSAfailure of bALP to decrease post op was also associated with shorter survival and disease free interval

Question 13

best candidate for appendicular OSA limb spare sx

Answer 13

distal radius OSArads/CT may underestimate marginMRI was more accurate with marginscintigraphy may overestimate margin variation within studies existed so no clear answer on best screening/staging imaging modality

Question 14

VSSO retrospective study on OSA related pathologic fractures fixed with internal fixation concluded what

Answer 14

bone plating, ILN, ESFMST 166

Question 15

fracture associated OSA

Answer 15

comminuted fracture >5 yrs prior with complicated healing, implant loosening, and or infectionmalignant transformation OSAtypically diaphyseal (not routine metaphyseal)associated with Jonas spring loaded IM pin (made of multiple types of metal and corrode easily)

Question 16

partial, subtotal, total scapulectomy

Answer 16

partial= removal of proximal scapula with preservation of acromion, acromial head of deltoid, and distal infra/supraspinatussubtotal = removes most of scapula but preserves glenoid and glenohumeral jointtotal = removes entire scapula including glenoid

Question 17

4 types of hemipelvectomies (differs from VSSO)

Answer 17

1. total2. mid to caudal : preserves cranial ilium/SI3. mid to cranial: includes SI and acetabulum4. caudal: preserves limb and acetabulumaim for 2-3 cm

Question 18

limb sparing techniques for distal radial OSA

Answer 18

1. cortical allograft/cement/plate2. pasteurized autograft/plate3. intraoperative radiation (autograft)–no resection, not recommended 4. endoprosthesis** most common5. vascularized autograft ulnar transposition/plate (ulnar rollover)6. stereotatic radiosurgery–no resection7. bone transport osteogenesis (DO–intramem ossification)8. ITAP (partial amputation with endoprothestic)tumors should inovle < 50% radial length; obtain 3 cm margins

Question 19

infection rate of cortical allograft limb spare

Answer 19

50% infection rateallograft does not incorporate into host bone during pets life therefor acts as a sequestrum and infection is a high risk complication of this procedure

Question 20

compare allograft vs endoprosthesis for limb spare distal radius

Answer 20

no difff in infection rate, infection severity, surgical time, limb use, implant failure rate or oncologic outcomeendoprosthesis failed at proximal screwallograft failed at distal screwother biomechanics studies show that endoprosthesis is superior

Question 21

three major complications of limb sparing surgery

Answer 21

1. infection 40-75%2. recurrence 25%3. implant failure 40%OTHER4. impaired venous/lymphatic drainage—swelling

Question 22

what positive finding is associated with infection and implant failure following limb sparing techniques

Answer 22

those patients with infection and implant failure had an INCREASED survival time

Question 23

T/Fappendicular chrondrosarcoma is associated with a lower metastatic rate and longer survival time than appendicular OSA

Answer 23

TRUEBUT survival time of patients with chondrosarcoma was significantly associated with tumor grade (decreased survival time with increasing grade)

Question 24

metastatic rate for cats with appendicular OSA

Answer 24

MUCH LOWER than dog appendicular OSAMST amputation alone = 17 -64 monthsMST amputation alone in dogs = 5 months

Question 25

according to Olbak et al Vet Surgery 2012 what was their final conclusion regarding pamidronate for survival times in dogs with appendicular primary bone tumors

Answer 25

addition of pamidronate into ANY protocol significantly DECREASED survival time

Question 26

differentials for tumors involving the joint

Answer 26

1. synovial cell sarcoma (15% based on cytokeratin stain--Goldens MST 32 mo)2. histiocytic sarcoma (50%; CD18--rottweilers MST 5 mo)3. synovial myxoma (20%--Dobies MST 30 mo)

Question 27

T/Fperiarticular histiocytic sarcoma carries a better prognosis that histocytic sarcoma in different locations

Answer 27

TRUE

Question 28

tumors of muscle

Answer 28

rhadomyosarcoma (type of STsarcoma)hemangiosarcoma (IM 275 d worse than SQ 1200 d)

Question 29

tumors of adipose tissue (3)

Answer 29

1. benign lipoma--includes IM lipomas2. infiltrative lipoma3. liposarcoma--METASTASIZE

Question 30

IM lipomas

Answer 30

benign caudal thigh btwn semimembranosus and semitendinosusnonpainfuladvanced imaging performed to RO infiltrative lipomano recurrence seen in 17 mo

Question 31

infiltrative lipoma

Answer 31

locally aggressive invading adjacent musclesDO NOT METadvanced imaging to determine extent of infiltration--do NOT contrast enhancerecurrence 36% even with aggressive sx

Question 32

liposarcoma

Answer 32

type of ST sarcomadiffers on advanced imaging bc ST density not just fat densitystill excellent long term px with excision

Question 33

digital masses in dogs

Answer 33

50-60% malignant dogs (70% in cats)SCCmalignant melanomaSCC causes more bone lysis than MM on rads

Question 34

T/F1 yr survival rates were significantly higher in dogs with subungual SCC (95%) vs SCC at other locations (60%)

Answer 34

TRUElabradors, poodles--large breed and black coatedbone lysislow met potential

Question 35

lung digit syndrome of cats

Answer 35

hi rate of adenocarcinoma on digits --usually affecting more than 1 digitmay be result of mets from bronchial adenocarcinoma bc evidence of ciliated epith with goblet cells that resemble pulmonary bronchial epithPOOR prognosis 67 days--surgery unlikely to change outcome