1、u IntroductionIntroduction ClassificationClassification Systematic Systematic ApproachApproach MRI MRI versus CTversus CTu Small Small pancreatic cystspancreatic cysts How How to reportto report ManagementManagementu PseudocystPseudocystu Cystic Cystic NeoplasmsNeoplasmsuAge Age and genderand gender
2、Serous Serous cystic neoplasmcystic neoplasmMucinous Mucinous Cystic Cystic NeoplasmaNeoplasmaIntraductalIntraductal Papillary Mucinous NeoplasmPapillary Mucinous NeoplasmuMainMain-duct IPMN-duct IPMNuBranchBranch-duct IPMN-duct IPMNu Uncommon Uncommon Neoplasms with specific findingsNeoplasms with
3、specific findingsSolid Solid PseudopapillaryPseudopapillary Neoplasm NeoplasmNeuroendocrine Neuroendocrine tumor with cystic degenerationtumor with cystic degenerationClassificationClassificationuPancreatic Pancreatic cysts can be categorized cysts can be categorized into the following groups:into t
4、he following groups:PseudocystsPseudocystsCommon cystic neoplasms:Common cystic neoplasms:uIPMN-IPMN-intraductalintraductal papillary mucinous neoplasm papillary mucinous neoplasmuSCN-Serous cystic neoplasmSCN-Serous cystic neoplasmuMCN-Mucinous cystic neoplasmMCN-Mucinous cystic neoplasmUncommon cy
5、stic neoplasms:Uncommon cystic neoplasms:uSPEN(solid SPEN(solid pseudopapillarypseudopapillary epithelial neoplasm)epithelial neoplasm)uTumors with cystic degeneration:Tumors with cystic degeneration:adenocarcinoma-neuroendocrine adenocarcinoma-neuroendocrine tumortumorSystematic Approachu The left
6、CT-image is of a patient with a history of pancreatitis.The left CT-image is of a patient with a history of pancreatitis.u There are two There are two unilocularunilocular or simple cysts.or simple cysts.u Notice also the retroperitoneal fat-stranding on the right.Notice also the retroperitoneal fat
7、-stranding on the right.u The most likely diagnosis is The most likely diagnosis is pseudocystspseudocysts.u The CT on the right shows a cyst in the pancreatic tail in a 36 year The CT on the right shows a cyst in the pancreatic tail in a 36 year old woman,which was found incidentally with US.old wo
8、man,which was found incidentally with US.u The cyst has a thick irregular rim and contains solid non-dependent The cyst has a thick irregular rim and contains solid non-dependent ponents.u The most likely diagnosis is a cystic neoplasm.The most likely diagnosis is a cystic neoplasm.MRI is usually of
9、 more diagnostic than CTuMRI MRI can show the cystic nature of a can show the cystic nature of a pancreatic lesion and its internal pancreatic lesion and its internal structure.structure.uThe MRI shows a large cyst with The MRI shows a large cyst with dependent internal debris(figure).dependent inte
10、rnal debris(figure).uPresence of internal dependent debris Presence of internal dependent debris appears to be a highly specific MR appears to be a highly specific MR finding for the diagnosis of pancreatic finding for the diagnosis of pancreatic pseudocystpseudocyst(6).(6).uMRI versus CTMRI versus
11、CTuCT will depict most pancreatic lesions,but is sometimes unable to depict the cystic CT will depict most pancreatic lesions,but is sometimes unable to depict the cystic ponent.uMR with heavily weighted T2WI and MRCP will better demonstrate the cystic nature and MR with heavily weighted T2WI and MR
12、CP will better demonstrate the cystic nature and the internal structure of the cyst and has the advantage of demonstrating the the internal structure of the cyst and has the advantage of demonstrating the relationship of the cyst to the pancreatic duct as is seen in IPMN.relationship of the cyst to
13、the pancreatic duct as is seen in IPMN.uThe images show a serous cystic neoplasm(SCN).MRI better shows the central scar The images show a serous cystic neoplasm(SCN).MRI better shows the central scar(figure).(figure).uThere are cases when CT can be helpful,since it better depicts a central There are
14、 cases when CT can be helpful,since it better depicts a central calcification in SCN or peripheral calcification in a mucinous cystic neoplasm(MCN).calcification in SCN or peripheral calcification in a mucinous cystic neoplasm(MCN).SCN with central scar seen on MRIMRI shows dependent debris in pseud
15、ocystMRI shows a lesion,which consists of multiple small cysts.This could be a serous cystic neoplasm or a branch-duct IPMN.The connection of the cystic lesion to the pancreatic duct indicates that this is a branch-duct IPMN.SMALL PANCREATIC CYSTSSMALL PANCREATIC CYSTSHow to reportHow to reportu Sma
16、ll Small pancreatic cysts have been documented in approximately pancreatic cysts have been documented in approximately 2.3%of CT studies and up to 19%of MR studies(11).2.3%of CT studies and up to 19%of MR studies(11).u Most of these cysts are found in asymptomatic patients,who are Most of these cyst
17、s are found in asymptomatic patients,who are studied for other reasons and represent benign or low-grade studied for other reasons and represent benign or low-grade indolent neoplasms.indolent neoplasms.u The ability of imaging to enable a specific diagnosis of an The ability of imaging to enable a
18、specific diagnosis of an individual pancreatic cyst is limited,but is easier in larger individual pancreatic cyst is limited,but is easier in larger cystic lesions.cystic lesions.u In most small cysts we should not attempt to characterize the In most small cysts we should not attempt to characterize
19、 the lesion and when we do,we should not be too confident.lesion and when we do,we should not be too confident.u The management of cystic neoplasms has not yet been standardized The management of cystic neoplasms has not yet been standardized and continues to evolve.and continues to evolve.u Accordi
20、ng to the recent 2012 consensus guidelines by Tanaka et According to the recent 2012 consensus guidelines by Tanaka et al the items mentioned in the Table should be addressed(8).al the items mentioned in the Table should be addressed(8).ManagementManagementu AgeAge,life-expectancy and comorbidity sh
21、ould be considered in,life-expectancy and comorbidity should be considered in the possible surveillance or treatment.the possible surveillance or treatment.u Cysts smaller than 3 cm and no worrisome or high risk-Cysts smaller than 3 cm and no worrisome or high risk-features can be considered for fol
22、low-up with either MRI,CT features can be considered for follow-up with either MRI,CT or ultrasound.or ultrasound.u Cysts with obvious high risk stigmata should be considered Cysts with obvious high risk stigmata should be considered for resection.for resection.u The table shows the American College
23、 of Radiology flowchart The table shows the American College of Radiology flowchart for imaging of incidentally discovered pancreatic cysts in for imaging of incidentally discovered pancreatic cysts in asymptomaticasymptomatic patients(11).patients(11).u Pancreatic cysts are regarded Pancreatic cyst
24、s are regarded symptomaticsymptomatic when there is when there is hyperamylasemiahyperamylasemia,recent-onset diabetes,severe,recent-onset diabetes,severe epigastricepigastric pain,weight loss,pain,weight loss,steatorrheasteatorrhea,or,or jaundicejaundice.PseudocystPseudocystukey findingskey finding
25、s:UnilocularUnilocular cyst without solid components,central scar cyst without solid components,central scar or wall calcification.or wall calcification.Collection of pancreatic enzymes,blood and necrotic Collection of pancreatic enzymes,blood and necrotic tissue.tissue.Debris within a cystic lesion
26、 is a Debris within a cystic lesion is a specificspecific MR MR finding(6).finding(6).History of pancreatitis or abdominal trauma.History of pancreatitis or abdominal trauma.Cysts develop Cysts develop in 4-6 weeks in 4-6 weeks-usually decrease in-usually decrease in size over time-sometimes enlarge
27、 or become infected.size over time-sometimes enlarge or become infected.Found in any part of the pancreas or anywhere within Found in any part of the pancreas or anywhere within the abdomen and sometimes even in the chest.the abdomen and sometimes even in the chest.u The CT demonstrates a large cyst
28、 in the upper abdomen The CT demonstrates a large cyst in the upper abdomen in a patient who had an acute pancreatitis.Notice in a patient who had an acute pancreatitis.Notice that there is also some ascites and pleural fluid.that there is also some ascites and pleural fluid.There wall enhances.Ther
29、e wall enhances.u Here an example of the value of MRI compared to CT.Here an example of the value of MRI compared to CT.u The MRI shows The MRI shows dependantdependant debris(arrow)as a debris(arrow)as a discriminator for walled off necrosis in a patient discriminator for walled off necrosis in a p
30、atient with a with a pseudocystpseudocyst.u CT demonstrates two large cysts in a 45 year old woman,who CT demonstrates two large cysts in a 45 year old woman,who had a trauma.had a trauma.u Notice some fat stranding in the retroperitoneal space Notice some fat stranding in the retroperitoneal space(
31、arrow).(arrow).u The imaging findings combined with the history make it very The imaging findings combined with the history make it very likely that these are traumatic likely that these are traumatic pseudocystspseudocysts.u Most Most pseudocystpseudocyst occur in the occur in the peripancreaticper
32、ipancreatic region,region,but rarely they may extend to the mediastinum.but rarely they may extend to the mediastinum.u This This patient has a chronic pancreatitis.patient has a chronic pancreatitis.u Notice the calcifications in the pancreatic head Notice the calcifications in the pancreatic head(
33、curved arrow).(curved arrow).u There are multiple There are multiple pseudocystspseudocysts extending all the way extending all the way to the mediastinum compressing the heart.to the mediastinum compressing the heart.Cystic NeoplasmsCystic NeoplasmsCystic Neoplasmsu The diagnosis of a cystic neopla
34、sm should be The diagnosis of a cystic neoplasm should be considered when there is no history of pancreatitis or considered when there is no history of pancreatitis or trauma.trauma.u Morphological characteristics of a cystic neoplasm are:Morphological characteristics of a cystic neoplasm are:thick
35、irregular rim,thick irregular rim,septationsseptations,solid components,a,solid components,a dilated pancreatic duct 3mm and calcifications.dilated pancreatic duct 3mm and calcifications.u In In many cases however it is not possible to make a many cases however it is not possible to make a definitiv
36、e diagnosis.definitive diagnosis.u It is important to make the diagnosis of a serous It is important to make the diagnosis of a serous cystic neoplasm,since this is the only tumor that has cystic neoplasm,since this is the only tumor that has no malignant potential.no malignant potential.u In many c
37、ases differentiation from a branch-duct IPMN In many cases differentiation from a branch-duct IPMN is difficult,since both have multiple small cysts.is difficult,since both have multiple small cysts.Age and genderAge and genderu Some Some cystic neoplasm are seen almost exclusively in cystic neoplas
38、m are seen almost exclusively in women,like mucinous cystic neoplasm(99%)and serous women,like mucinous cystic neoplasm(99%)and serous cystic neoplasm(75%).cystic neoplasm(75%).u Solid Solid pseudopapillarypseudopapillary epithelial neoplasm is another epithelial neoplasm is another pancreatic tumor
39、 which may have cystic components.pancreatic tumor which may have cystic components.u It is uncommon,but is seen exclusively in young women.It is uncommon,but is seen exclusively in young women.Hence the following rule:Hence the following rule:Grandma-Serous cystic adenomaMother-Mucinous cystic neop
40、lasmDaughter-Solid pseudopapillary epithelial neoplasm SPENSEROUS CYSTIC NEOPLASMSEROUS CYSTIC NEOPLASMkey findings:u Benign Benign tumor,but large tumors have a tendency to increase in size tumor,but large tumors have a tendency to increase in size and cause symptomsand cause symptomsu Typically se
41、en in GrandmaTypically seen in Grandmau MicrocysticMicrocystic or honey-combed cyst with central scar(30%)and or honey-combed cyst with central scar(30%)and calcifications(18%)calcifications(18%)uMacrocysticMacrocystic in 10%and difficult to differentiate in 10%and difficult to differentiate from fr
42、om pseudocystpseudocyst and mucinous cystic neoplasm and mucinous cystic neoplasmu Lobulated surfaceLobulated surfaceu No communication between cysts and pancreatic duct.No communication between cysts and pancreatic duct.uHypervascularHypervascular enhancement is sometimes seen and enhancement is so
43、metimes seen and can look like cystic neuroendocrine tumorcan look like cystic neuroendocrine tumoru Growth rate of Growth rate of tumorstumors：Growth Growth rate of tumors 4 cm:up to 20 mm/yrate of tumors 4 cm:up to 20 mm/ySerous cystic adenomas contain multiple small cysts resulting in a lobulated
44、 contour.Some have a central scar with calcifications.u The pathology specimen shows multiple The pathology specimen shows multiple microcystsmicrocysts,which,which gives the tumor a lobulated appearance.gives the tumor a lobulated appearance.u A A macrocysticmacrocystic serous cystic neoplasm is ra
45、re and,although serous cystic neoplasm is rare and,although benign,can be similar in appearance to the potentially benign,can be similar in appearance to the potentially malignant malignant macrocysticmacrocystic mucinous cystic neoplasm.mucinous cystic neoplasm.Courtesy of Dr Allen,HPB surgery,Memo
46、rial Sloan Kettering Cancer Center,NYuA characteristic feature of a serous cystic A characteristic feature of a serous cystic neoplasm is a central scar,sometimes with neoplasm is a central scar,sometimes with calcifications.calcifications.uSometimes the Sometimes the microcysticmicrocystic componen
47、t of this component of this tumor is difficult to identify on CT.tumor is difficult to identify on CT.uMR will better identify the internal MR will better identify the internal architecture.architecture.uMRI is also useful in determining if the MRI is also useful in determining if the cysts communic
48、ate with the pancreatic duct cysts communicate with the pancreatic duct or not to differentiate this lesion from a or not to differentiate this lesion from a branch-duct IPMN(see below).branch-duct IPMN(see below).u The pathology specimen shows a cystic tumor with The pathology specimen shows a cyst
49、ic tumor with multiple small cysts and a central scar.multiple small cysts and a central scar.u There There are no calcifications.are no calcifications.Courtesy of Dr Klimstra,pathology of the Memorial Sloan Kettering Cancer Center,NY,u CT-image of a 51 year old woman with a history of CT-image of a
50、 51 year old woman with a history of gallstones and abdominal pain.gallstones and abdominal pain.u There is a There is a hypodensehypodense lesion with central calcification lesion with central calcification in the head of the pancreas.in the head of the pancreas.u The lesion has a lobulated contour
