1、肾脏囊性占位2013-11肾脏囊性占位IntroductionIgnore,Follow or ExciseRadiological InterpretationCalcificationHyperdense or High signalSeptationsEnhancementMultiloculatedNodularityWall thickeningRole of BiopsyDr Bosniaks opinionBosniak Classification of Renal Cystic Disease肾脏囊性占位肾脏囊性占位Even on gross examination a cy
2、stic renal cell carcinoma(left)may be indistinguishable from a complicated cyst(right)肾脏囊性占位Ignore,Follow or ExciseIgnore,Follow or ExciseRenal cysts can be classified according to the Bosniak Renal cysts can be classified according to the Bosniak classification depending on their features.classific
3、ation depending on their features.Type I cysts are simple cysts.Type I cysts are simple cysts.Type II are the minimally complicated cysts.Type II are the minimally complicated cysts.Type I and II can be ignored.Type I and II can be ignored.Type II F are probably benign,but need to be Type II F are p
4、robably benign,but need to be followed.followed.Type III and IV both are surgical lesions.Type III and IV both are surgical lesions.Type IV is inevitably malignant and in the type III Type IV is inevitably malignant and in the type III group about 80-90%turn out to be malignant as well.group about 8
5、0-90%turn out to be malignant as well.In our communication with the clinicians it is In our communication with the clinicians it is important,that we explain the significance of our important,that we explain the significance of our findings and the meaning of the classification in findings and the m
6、eaning of the classification in terms of:Ignore(type I and II),Follow(type IIF)or terms of:Ignore(type I and II),Follow(type IIF)or Excise(type III and IV).Excise(type III and IV).So in this lecture we will only talk about Ignore,So in this lecture we will only talk about Ignore,Follow or Excise.Fol
7、low or Excise.For those who want to see the original Bosniak For those who want to see the original Bosniak classification,look at the table which is presented classification,look at the table which is presented at the end of the lecture.at the end of the lecture.肾脏囊性占位肾脏囊性占位 Radiological Interpreta
8、tion Although the final differentiation of cystic renal masses is based upon histologic diagnosis,there are imaging findings that tell you that a cyst is not a simple cyst and whether it is probably benign or malignant.The following imaging features indicate that a cyst is NOT simple:-Calcification-
9、Hyperdense/high signal-Septations-Multiple locules-Enhancement-Nodularity/wall thickening肾脏囊性占位 Differentiation is based upon histologic Differentiation is based upon histologic diagnosis,but Imaging is a reliable means diagnosis,but Imaging is a reliable means for differentiating benign from malign
10、ant for differentiating benign from malignant cystic lesions cystic lesions 肾脏囊性占位The table on the left summarises these imaging features together with the management consequences:Ignore,Follow or Excise.When we look at these imaging features,we have to realise,that the most worrisome portion of a c
11、ystic mass should be used in deciding appropriate management.So when the findings are discordant either within one examination or using different radiological examinations,the lesion should be managed based upon the most aggressive imaging findings.When we look at the table on the left,we can say th
12、at we are pretty good with the first 3 parameters(calcification,hyperdens and septations),because we are correct in about 95%of the cases.The other four are even more easy,because when you have any of these(enhancement,multiloculated,nodularity or wall thickening),the lesion is almost always a surgi
13、cal lesion.Regarding follow up,there are no rules at the moment.One could do a follow up at 6 months and if the lesion is stable then double the follow up time.We will now discuss all these imaging features in detail.肾脏囊性占位肾脏囊性占位Calcification The most important thing is a good description of the typ
14、e of calcifications.We can ignore small amounts of calcification that are smooth,septal or if it is milk of calcium,which moves to the lowest point with positional changes.We have to make sure,that no enhancement(=All lesions that show enhancement and lesions with wall thickening or nodularity of th
15、e wall outside the calcifications should be excised.We can follow lesions with thick or nodular calcification without any enhancement.肾脏囊性占位肾脏囊性占位Benign calcifications:small punctate and milk of calcium.Ignore On the left we see a cystic lesion.There is a small punctate calcification that we can ign
16、ore.On the bottom of the cyst there is a layer of calcium typical for milk of calcium.This is also a benign calcification that we can ignore.肾脏囊性占位LEFT:NECT with a smooth LEFT:NECT with a smooth linear calcification and linear calcification and nodular calcification.RIGHT:nodular calcification.RIGHT
17、:Enhanced CT shows Enhanced CT shows enhancement.Exciseenhancement.Excise On the left a On the left a patient with patient with nefrolithiasis.nefrolithiasis.There is also a There is also a cystic lesion with cystic lesion with linear and nodular linear and nodular calcification.If calcification.If
18、there were only there were only these linear these linear calcifications we calcifications we could ignore the could ignore the lesion.In case of lesion.In case of nodular nodular calcification we can calcification we can follow it,if there follow it,if there is no enhancement.is no enhancement.In t
19、his case however In this case however we see enhancement,we see enhancement,so this lesion has so this lesion has to be excised.to be excised.肾脏囊性占位On CT hyperdense means:20 HU on a NECTOn MRI hyperintense means all that has higher signal intensity than water on a T1 weighted image.Hyperdensity or h
20、yperintensity usually indicates hemorrhage or high protein content of the cyst.Ignore all lesion with sharp margins;lesions On US they have to be clearly cysticFollow all lesions that are totally intrarenal,because you can not appreciate the wall and follow all lesions 3 cm,because there is at the m
21、oment not much experience with these lesions.All these lesions must show no enhancement.Excise all lesions that are poorly defined or heterogenous or show enhancement.Also when ultrasound shows that the lesion is solid,the lesion should be excised.Hyperdense or High signal肾脏囊性占位LEFT:NECT shows a les
22、ion LEFT:NECT shows a lesion with a density of 27 with a density of 27 HU.IgnoreRIGHT:MRI HU.IgnoreRIGHT:MRI shows a intrarenal lesion shows a intrarenal lesion that is hyperintense on T1:that is hyperintense on T1:higher signal than higher signal than water.Followwater.Follow On the left we see a O
23、n the left we see a hyperdens cystic hyperdens cystic lesion on CT and a lesion on CT and a hyperintense lesion hyperintense lesion on a T1-weighted MR.on a T1-weighted MR.Both lesions have a Both lesions have a sharp margin and are sharp margin and are homogeneous,although homogeneous,although ther
24、e is some noise there is some noise in the CT image.in the CT image.On the enhanced scans On the enhanced scans(not shown)the(not shown)the lesions didnt show lesions didnt show any enhancement.any enhancement.We therefore can We therefore can ignore the lesion on ignore the lesion on the left and w
25、e have the left and we have to follow the lesion to follow the lesion on the right,because on the right,because it is totally it is totally intrarenal.intrarenal.肾脏囊性占位SeptationsSeptations Ignore thin Ignore thin septations septations(Follow all(Follow all septations that are septations that are onl
26、y slightly only slightly greater than greater than hairline.They hairline.They still have to show still have to show no enhancement.no enhancement.Excise all Excise all septations that are septations that are thick,irregular or thick,irregular or nodular and all nodular and all septations that septa
27、tions that show enhancement.show enhancement.肾脏囊性占位LEFT:thin,smooth LEFT:thin,smooth septation.IgnoreRIGHT:septation.IgnoreRIGHT:thick enhancing thick enhancing septation.Exciseseptation.Excise On the left we see On the left we see 2 cases2 casesThere is a cystic There is a cystic lesion with a thin
28、 lesion with a thin smooth non smooth non enhancing septation enhancing septation that we can ignore.that we can ignore.The other case is a The other case is a thick enhancing thick enhancing septation that has septation that has to be excised.to be excised.肾脏囊性占位Cystic lesion with thick Cystic lesi
29、on with thick septation and a nodule.septation and a nodule.ExciseExcise The ultrasound image on the left shows a thick septation.There is also a nodule in the wall of the cyst.So we have two reasons to excise this cystic lesion.肾脏囊性占位EnhancementEnhancement Enhancement is our Enhancement is our best
30、 predictable best predictable sign of malignancy.sign of malignancy.So we have to So we have to excise all lesions,excise all lesions,that clearly show that clearly show enhancement.enhancement.The only exception The only exception is infectionis infection.肾脏囊性占位Significant enhancement:Significant e
31、nhancement:Unenhanced CT:44 HU Unenhanced CT:44 HU(left)Enhanced scan:61 HU(left)Enhanced scan:61 HU(right).Excise(right).Excise Enhancement is defined as follows:Increase in Hounsfield Units of the mass after contrast injection:10-15 HU=indeterminate 15 HU=vascularityOn MR:15%=enhancement=surgical肾
32、脏囊性占位Enhanced CT shows Enhanced CT shows enhancement of a thick enhancement of a thick wall and a central wall and a central area.excisearea.excise The case on the left doesnt shows much on the NECT.However when we give contrast we can appreciate a thick wall and we see enhancement both of the wall
33、and of a central area in the medial part of the cystic lesion.We should never see this in an benign cyst,so this is a surgical lesion.肾脏囊性占位MultiloculatedMultiloculated Masses with three or more septa are not called multiseptated but multiloculated.All multiloculated lesions should be excised,unless
34、 there is clear evidence of infection.肾脏囊性占位Multiloculated cystic Multiloculated cystic mass on US and on CT.mass on US and on CT.ExciseExcise In the adult,the two In the adult,the two most common most common multiloculated masses multiloculated masses are MLCN are MLCN(multilocular cystic(multilocu
35、lar cystic nephroma)which is nephroma)which is usually benign,but usually benign,but sometimes malignant sometimes malignant and MLRCC and MLRCC(multilocular renal(multilocular renal cell carcinoma)which cell carcinoma)which is always malignant.is always malignant.On imaging there is On imaging ther
36、e is no way that we can no way that we can separate these two separate these two and therefore,all and therefore,all multiloculated masses multiloculated masses are surgical(unless are surgical(unless infection).infection).肾脏囊性占位Multilocular renal cell Multilocular renal cell carcinoma(left)and a ca
37、rcinoma(left)and a multilocular cystic nephroma multilocular cystic nephroma(right)(right)Even the pathologist Even the pathologist can not separate the can not separate the usually benign usually benign multilocular cystic multilocular cystic nephroma from the nephroma from the malignant malignant
38、multilocular renal multilocular renal cell carcinoma on cell carcinoma on gross specimen.gross specimen.The differentiation The differentiation is based on the is based on the histology of the histology of the epithelial cells epithelial cells lining these locules.lining these locules.So all multilo
39、cular So all multilocular renal masses have to renal masses have to be excised.be excised.肾脏囊性占位NodularityNodularity Ignore:noneFollow:only very small nonenhancing nodules,and follow carefullyExcise:all other nodular lesions 肾脏囊性占位Very small non enhancing Very small non enhancing nodules.Follownodul
40、es.Follow The case on the The case on the left shows very left shows very small nodules on a small nodules on a CECT and a T2WI.CECT and a T2WI.From all the other From all the other images we could images we could tell that they were tell that they were not enhancing.not enhancing.So we can probably
41、 So we can probably follow this lesion.follow this lesion.If they start to If they start to grow or show any grow or show any enhancement,then enhancement,then we have to excise we have to excise the lesion.the lesion.肾脏囊性占位Cystic lesion with a big Cystic lesion with a big enhancing nodule.enhancing
42、 nodule.ExciseExcise On the left an On the left an easy case.easy case.There is a big There is a big nodule with nodule with enhancement,so enhancement,so this lesion has this lesion has to be excised.to be excised.Even if there Even if there was no was no enhancement,the enhancement,the lesion stil
43、l had lesion still had to be excised.to be excised.肾脏囊性占位T2WI shows a multiloculated T2WI shows a multiloculated cystic mass with multiple cystic mass with multiple nodules.Excisenodules.Excise The case on the The case on the left is a T2WI left is a T2WI with Fatsat.with Fatsat.We see multiple We s
44、ee multiple nodules so this nodules so this mass has to be mass has to be excised.excised.It doesnt It doesnt matter whether matter whether or not these or not these nodules enhance.nodules enhance.肾脏囊性占位Wall thickeningWall thickening All lesions with All lesions with a thickened wall,a thickened wa
45、ll,with or without with or without enhancement,enhancement,should be should be excised,unless excised,unless there is clear there is clear evidence of evidence of infection.infection.In these latter In these latter cases the cases the lesions should lesions should be followed.be followed.肾脏囊性占位Two c
46、ysic lesions with a Two cysic lesions with a regular thick wall.Exciseregular thick wall.Excise On the left we see two On the left we see two renal lesions that are renal lesions that are cystic.cystic.The lesion on the far left The lesion on the far left clearly shows a thickened clearly shows a th
47、ickened wall.This is easy to wall.This is easy to appreciate because part of appreciate because part of the lesion is extrarenal.the lesion is extrarenal.The cystic lesion next to The cystic lesion next to it is totally intrarenal,it is totally intrarenal,which makes it harder to which makes it hard
48、er to appreciate,but there is appreciate,but there is wall tickening.wall tickening.So both lesions have to be So both lesions have to be excised,whether there is excised,whether there is enhancement of the wall or enhancement of the wall or not.not.The only exception would The only exception would
49、be if there were evident be if there were evident signs of infection.signs of infection.肾脏囊性占位Cystic lesion with a thick Cystic lesion with a thick irregular enhancing irregular enhancing wall.Excisewall.Excise The cystic The cystic lesion on the lesion on the left is left is clearly a clearly a sur
50、gical surgical lesion.lesion.It has a It has a thick thick irregular irregular wall,it is wall,it is exophytic and exophytic and shows shows enhancement.enhancement.肾脏囊性占位Role of BiopsyRole of Biopsy In the literature there are In the literature there are different opinions concerning different opin
