What’sYourDiagnosis???

RenéeFahrenholz,Classof2012

Signalment‐“Emma”,a9yearold,Female,Spayed,DomesticShortHairedFeline

PresentingComplaint‐Weightloss,vomitedthemorningofhervisit,pendulousabdomen,andpalemucusmembranes

History‐Emmawasvomitingoccasionallyathome.HerownernoticedthatEmmawasn’therusualselfforthepastcoupleofdays;shelayaroundallnightinsteadofroamingthehouselikenormal.Accordingtoherowner,Emmahadnoturinatedordefecatedduringthistime.ItwasalsonotedthatEmmawaslosingweightoverthelast3months.

PhysicalExam‐UponpresentationtoKSUhervitalswereasfollows;Temperature=102.4F,HeartRate=160b/min,RespiratoryRate=28b/min,BCS=2/5,Weight=3.48kgs,MucusMembranes=pale.Emma’sabdomenwassoftandpendulous.Alarge,palpablemasswasfeltinherrightabdomen.Peripherallymphnodeswerenormalinsizeandshape.Dehydrationwasnoted.Emma’sheartauscultatednormally.

DDx‐Renomegaly:Hydronephrosis,RenalInfection/Abcessation,Neoplasiasuchaslymphoma.

DiagnosticsandTreatmentsbyVisit:

3/07/12:CompleteBloodCount,Chemistry,Urinalysis,AbdominalRadiographs,AbdominalUltrasound,FeLV/FIVTest

AcompletebloodcountwasperformedandresultsindicatedahighWBCcount.Therewasanacuteinflammatoryleukogram.ThechemistryresultsshowedelevatedlevelsofBUNandCreatinine.TheUSGwas1.037andtheurinalysisresultswerepositiveforprotein.Therewereoccasionalstruvitecrystals.TheFeLV/FIVtestwasnegative.

Radiographs‐AVDand2RightLateralAbdominalViewsweretaken.

Figure 1‐ VD Abdomen 

Theleftkidneyisnormalinsizeandshape.Thereisamassintherightcraniodorsalabdomen.Thereiscaudalandleftdisplacementofthesmallintestine.Differentialsforrightmass:renomegaly,hydronephrosis,perirenalcyst,neoplasia,granuloma,orabscess.Onthelateralview,therearetwosmall,welldefinedmineralopacitieslocatedcaudaltotherightkidney.Oneopacityissuperimposedwith

Figure 3‐ Right Lateral Abdomen compression with wooden spatula 

Figure 2‐ Right Lateral Abdomen 

theregionoftherightkidneyontheventrodorsalview.Botharesuperimposedwiththeleftrenalsilhouette.Oneopacitymoveswithcompression.

Suspectrightureterolithandleftnephrolith.

Atthecompletionofthisvisit,EmmawasprescribedClavamoxforpossibleinfectionandsenthomewithsubcutaneousfluids

Ultrasound‐Anabdominalultrasoundwasperformedon3/7/12.

Figure 4‐ Left Kidney with hyperechoic foci 

Figure 5‐ Right Kidney with irregular margins and bordered by fluid 

3/7/12:Therightkidneyismarkedlyenlargedandhasirregularmargins.Theinternalarchitectureoftherightkidneyisdistorted.Therenalpelvisandcollectingsystemaredilatedwithechogenicmaterial.Thereareseveralvariablysizedhyperechoicfocipresentintherightkidney.Theproximalureterisdilatedandtorturous.Theleftkidneywasofnormalsizeandcontainedmultiplesmallhyperechoicfoci.

3/08/12:UltrasoundGuidedFineNeedleAspirates,CytologyandAerobicCultureofaspirates

Cytologyrevealedneutrophilicinflammationanddegenerateneutrophils.AerobicCulturedidnothavegrowthpresent.Theculturewasnegative.

3/13/12:ProfileRenalChemistryBloodwork,AbdominalUltrasound

RenalProfile:AzotemiaandincreasedPhosphorus

ContinueClavamoxandSubcutaneousFluids

RecommendHill’sK/DDietandconsultswithInternalMedicineandSurgeryServices

Ultrasound‐3/13/12

OwnerreportedthatEmmawasdoingbetterathome.

Thedilationoftherenalcollectingsystemismoresevere.Thereisincreasedhypoechoicmaterialsurroundingthekidney,whichappearstobebetterencapsulated.

Dx‐Rightkidneyhydronephrosis,rightureterolith,softtissuestructuresandeffusionnotedinretroperitonealspacemayrepresenturinoma,abscessorretroperitonitis.Leftnephrocalcinosis/nephrolith.

TxRecommendations‐AssessmentofEmma’sglomerularfiltrationrateandsurgicalremovaloftherightkidney.

Figure 7‐ Right Kidney with increased perirenal fluid 

Figure 8‐ Right Kidney with increased perirenal fluid 

Tx‐Ownerelectedconservativemanagement.Antibiotics:Clavamoxgivenevery12hoursuntilgonefortreatmentofinfection.PainMedication:Buprenorphinegiventransmucosallyevery6‐8hoursforpain.SubcutaneousFluids:150mlLRStobegivenathomeeachday.DiscussionHydronephrosisisaseriousconditionthatresultsindistensionoftherenalpelvisandrenalcalicieswithurineduetoanobstruction.Hydronephrosiscanleadtoatrophyoftherenalparanchyma,causingdistortionoftherenalarchitecture.Iftheobstructionisinthelowerurinarytract,hydrouretercanbeseen.Astheprocessofhydronephrosiscontinues,thekidneywilltransformintoanon‐functionalsacfilledwithfluid.Theobstructionofurineoutflowcanbecongenitalduetomalformedureterorkidney,oracquiredduetoneoplasia,ureterstricture,orureteroliths.Emma’shydronephrosisismostlikelyduetoaureteralcalculus.Thesofttissuestructuresandeffusionnotedinretroperitonealspacemayrepresentaurinoma,abscessorretroperitonitis.Furtherdiagnosticsarerequiredinordertodeterminetheirorigin.

RenalAbscesses

Renalabscessesusuallyoccurduetoascendingurinaryinfection.Insomecases,tissuebreakdownandnecrosiswilloccur,leadingtomicroabscessformation.Thesecanliquefyandcoalesceintolargeabscesses.Extra‐renalabscessusuallyresultsfromruptureofarenalabscessorinfectedhydronephrosisthroughtherenalcapsule.

Renalabscessesaremostcommonlyasequelaofsevere,acutepyelonephritis.Theyfailtorespondtoappropriateantibiotictherapy.Patientsmayalsohaveanonsetofsymptomswithabsenceoflocalizingsignssuchasflankpain,pyuriaorbacteriuria.Renalabscessescanbeidentifiedwithultrasound.Theabscesscanappearsimilartoacystwhenviewedwithultrasound,butcanalsomimicarenalneoplasm.Sometimestheabscessmaybeindistinguishablefromadjacentrenalparenchyma.Abscessescancontainavariablemixtureofanechoic,hypoechoic,andhyperechoiccomponents.

Urinomas

Aurinomaisanencapsulatedextravasationofurinethatformsthroughatearinthecollectingsystemortheproximalureterwhenureteralobstructionispresent.Causesforurinomasincludeiatrogenicorsurgicaltrauma,uretericobstruction,ureteraltumor,stones,andperiuretericfibrosis.Acuteorsubacuteoutflowobstructioncancauseurinetoleakintotheperirenalspace.Urinomashavearadiologicalappearanceofasofttissuemass.Largelesionscandisplacethekidney.Radiologicalandultrasonographicfindingsofchronicobstructionareoftenpresent.