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Flashcards in 72. MS neoplasia_Limbspare Deck (35):

the most common primary bone tumor in dogs

OSA 85% bone tumors in dogsappendicular vs axial


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

TRUEearly OHE/neuter may actually increase risk OSA


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



difference btwn axial and appendicular OSA

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


where is the predilection of appendicular OSA

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


types of OSA

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


bone biopsy

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%


diagnostic accuracy of FNA

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


mets and OSA

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


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

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


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

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


ALP in OSA prognosis

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


best candidate for appendicular OSA limb spare sx

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


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

bone plating, ILN, ESFMST 166


fracture associated OSA

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)


partial, subtotal, total scapulectomy

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


4 types of hemipelvectomies (differs from VSSO)

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


limb sparing techniques for distal radial OSA

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


infection rate of cortical allograft limb spare

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


compare allograft vs endoprosthesis for limb spare distal radius

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


three major complications of limb sparing surgery

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


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

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


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

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


metastatic rate for cats with appendicular OSA

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


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

addition of pamidronate into ANY protocol significantly DECREASED survival time


differentials for tumors involving the joint

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)


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



tumors of muscle

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


tumors of adipose tissue (3)

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


IM lipomas

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


infiltrative lipoma

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



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


digital masses in dogs

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


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

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


lung digit syndrome of cats

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

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