肾脏囊性占位.ppt

肾脏囊性占位IntroductionIgnore,Follow or ExciseRadiological InterpretationCalcificationHyperdense or High signalSeptationsEnhancementMultiloculatedNodularityWall thickeningRole of BiopsyDr Bosniaks opinionBosniak Classification of Renal Cystic Disease Even on gross examination a cystic renal cell carcinoma(left)may be indistinguishable from a complicated cyst(right)Ignore,Follow or ExciseRenal cysts can be classified according to the Bosniak classification depending on their features.Type Icysts are simple cysts.Type IIare the minimally complicated cysts.Type I and II can be ignored.Type II Fare probably benign,but need to be followed.Type III and IVboth are surgical lesions.Type IV is inevitably malignant and in the type III group about 80-90%turn out to be malignant as well.In our communication with the clinicians it is important,that we explain the significance of our findings and the meaning of the classification in terms of:Ignore(type I and II),Follow(type IIF)or Excise(type III and IV).So in this lecture we will only talk about Ignore,Follow or Excise.For those who want to see the original Bosniak classification,look at the table which is presented at the end of the lecture.Radiological Interpretation 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-Hyperdense/high signal-Septations-Multiple locules-Enhancement-Nodularity/wall thickening Differentiation is based upon histologic diagnosis,but Imaging is a reliable means for differentiating benign from malignant cystic lesions 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 cystic 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 that 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 surgical 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.Calcification The most important thing is a good description of the type 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 the wall outside the calcifications should be excised.We can follow lesions with thick or nodular calcification without any enhancement.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 ignore.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.LEFT:NECT with a smooth linear calcification and nodular calcification.RIGHT:Enhanced CT shows enhancement.Excise On the left a patient with nefrolithiasis.There is also a cystic lesion with linear and nodular calcification.If there were only these linear calcifications we could ignore the lesion.In case of nodular calcification we can follow it,if there is no enhancement.In this case however we see enhancement,so this lesion has to be excised.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 hyperintensity 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 moment 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.HyperdenseorHighsignalLEFT:NECT shows a lesion with a density of 27 HU.IgnoreRIGHT:MRI shows a intrarenal lesion that is hyperintense on T1:higher signal than water.Follow On the left we see a hyperdens cystic lesion on CT and a hyperintense lesion on a T1-weighted MR.B