untitled

Transcription

1 대한소화기학회지 2008;52: REVIEW 췌관내유두상점액종양 (IPMN) 의진단 연세대학교의료원영상의학교실방사선의과학연구소 *, 연세대학교의료원 BK21 연세의과학사업단소화기병연구소 홍혜숙 * ㆍ김명진 * Diagnosis of Pancreatic Intraductal Papillary Mucinous Neoplasm Hye-Suk Hong, M.D.* and Myeong-Jin Kim, M.D.* Department of Radiology and Research Institute of Radiological Science, Yonsei University Health System*, Institute of Gastroenterology and Brain Korea 21 Project, Yonsei University Health System, Seoul, Korea Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a unique disease entity that is characterized by predominant intraductal growth of mucinous cells, copious mucin production, and subsequent cystic dilatation of pancreatic ducts. IPMN shows a spectrum of histologic and imaging findings and possesses as the potential for malignant transformation arising from adenoma to invasive carcinoma. It is important to determine the type, extent of duct involvement, and presence of malignant transformation, and to assess tumor grading prior to surgical resection. Thus, it would be helpful for physicians managing patients with IPMN of the pancreas to have a guideline for the diagnosis and treatment of IPMN. In this review, a role of radiological evaluation for diagnosis and preoperative assessment is described as well as presentation of the guideline for patient management. (Korean J Gastroenterol 2008;52: ) Key Words: Pancreatic cystic tumor; Intraductal papillary mucinous neoplasm; Computed tomography; Magnetic resonance imaging 서론췌장의관내유두상점액종양 (intraductal papillary mucinous neoplasm, IPMN) 은점액생성과췌관의현저한확장을동반하는관내유두상종양이다. 1 IPMN은양성선종의형태로나타나거나형성이상 (dysplasia), 상피내암종 (carcinoma in situ) 및침윤암종 (invasive carcinoma) 등의다양한임상병리학적인소견을보이며수술치료후임상결과와예후에서도다른양상을보인다. 2,3 침윤 IPMN의예후는매우불량하여췌장선암종과동등한정도이나양성 IPMN 및상피내암종 IPMN은수술로종양이완전절제되면완전치유등우수한 예후를기대할수있다. 4,5 IPMN에대한지식이축적되고진단의정확성이높아짐에따라환자진료에있어적절한가이드라인이필요할것으로생각한다. 최근높은해상도를가진 multi-detector row computed tomography (MDCT) 와 magnetic resonance imaging/magnetic resonance cholangiopancreatography (MRI/MRCP) 의이용으로 IPMN의감별진단과수술전종양평가의정확성이높아지고있다. 본고에서는, 췌장 IPMN의진단에도움이되는특징적인영상소견과단계적인등급에따른영상소견의차이, 다른췌장낭성병변과의감별진단, 수술의적응과추적검사에서의소견에관해진단과치료에도움되는소견을제시하고자한다. 연락처 : 김명진, , 서울시서대문구성산로 250 연세대학교의과대학영상의학교실 Tel: (02) , Fax: (02) kimnex@yuhs.ac Correspondence to: Myeong-Jin Kim, M.D. Department of Radiology, Yonsei University College of Medicine, 250, Seongsanno, Seodaemun-gu, Seoul , Korea Tel: , Fax: kimnex@yuhs.ac

2 208 대한소화기학회지 : 제 52 권제 4 호, 2008 IPMN의진단병리적으로 IPMN은주췌관과주요췌관분지 (major branch duct) 에서발생하며주로췌관내에국한되어유두상형태로성장하고다양한양의점액생성에따른췌관의이차적인낭성확장을특징으로한다. 췌관에서발생한형태에따라주췌관형, 부췌관형및복합형으로분류된다. IPMN의피복상피 (covering epithelium) 는췌장의점액낭종 (mucinous cystic neoplasm, MCN) 을구성하는점액상피와병리적으로동일하고두종양모두에서점액을생성할수있으나, IPMN에는점액낭종의진단에특징적인난소기질 (ovarian stroma) 이없다. 2,3,6 2000년 World Health Organization에의해 IPMN은병리적으로종양을이루는상피세포의형성이상정도에따라 4단계 (adenoma, borderline, carcinoma in situ, invasive carcinoma) 로분류되었으며, 한종양내에서도 4단계의형성이상이다양한정도로모두나타날수있고양성선종에서변성을거쳐종국에는악성침윤암종으로발전한다는가설이지지되었다. 3 IPMN에서침윤암의발생빈도는 30-35% 정도이다. 6 그러나, 모든 IPMN에서악성침윤암종이발현되는지, 각단계의형성이상에서침윤암종으로변성되기까지얼마의기간이걸리는지에관해서는아직분명하게밝혀져있지않고, 종양이발생한췌관의부위 (main duct or branch duct) 에따라서도악성변성의발현도가다르다는사실이많은연구들에서보고되었다. IPMN에서악성암이발생하는빈도는주췌관형에서는 57-92%, 부췌관형에서는 6-46% 정도이다 영상진단법 CT와 MRI/MRCP는병변의해부학적인위치를규명하고주변장기와의관계및국소종양침윤도, 원격전이등을평가함으로써 IPMN의영상진단에중추적인역할을하고있으며내시경초음파, 내시경역행담췌관조영술 (endoscopic retrograde cholangiopancreatography, ERCP) 등도진단에이용되고있다. 각영상방법간의진단적인효율과정확성은다양한결과를보이며종양의진단에서로보완적인역할을한다. CT나 MRI로주췌관형과부췌관형을구별하는정확도는 80-88% 이고수술전 IPMN의양성과악성종양의감별은영상기법에따라 53-82% 정도의정확도를보인다 최근컴퓨터기술의발전과더불어촬영후다양한영상재구성을활용한기법들이 IPMN의진단에이용되고있다. 3차원재구성을이용한고해상도다평면영상, 주췌관의주행을따라재구성하여췌장전체를한평면으로볼수있는곡면영상및 3차원박편 MRCP 등으로 IPMN 병변과주췌관의연결을영상에서더욱정확하게평가할수있고췌관내종양결절과병변의범위평가및악성종양의감별에도정확도가증가하였다. 14,16 2. IPMN의특징적인영상소견 CT나 MRI를이용한영상검사에서 IPMN은종양이췌관에서병발한위치에따라다른양상을보이는데주췌관에서발생하였을경우미만또는분절성으로주췌관확장을보이고부췌관형에서는내부에격벽이있는단일낭성병변또는포도송이모양으로여러개의작은낭들이모여있는소견을보이며주췌관은늘어나지않거나경미한확장을동반한다 (Fig. 1, 2). 늘어난주췌관이나낭성병변내부에유두 Fig. 1. CT and MRCP images of branch duct intraductal papillary mucinous adenoma. (A, B) Axial (A) and coronal (B) reformatted images obtained with multi-detector row CT clearly demonstrate a cystic mass in the pancreatic head. The whole length of main pancreatic duct is clearly visualized and diffusely dilated. (C) Two-dimensional MRCP image demonstrates a clustered cystic mass in the pancreatic head communicated with main pancreatic duct. MRCP, magnetic resonance cholangio-pancreaticography.

3 홍혜숙외 1 인. 췌관내유두상점액종양 (IPMN) 의진단 209 Fig. 2. Three-dimensional curved planar reformatted CT images of main duct intraductal papillary mucinous neoplasm, borderline. (A, B) The images show diffusely dilated main pancreatic duct with a small mural nodule (arrow in A). Fig. 3. CT and MRCP images of invasive mucinous papillary carcinoma. (A) Axial multi-detector row CT image shows a cystic and solid mass with calcifications in the pancreatic head. The solid portion of the mass has infiltrative border to parenchyma (arrow). (B) On MRCP image, a cystic mass with soft-tissue filling defect (arrow) is demonstrated in the pancreatic head. Invasion of distal CBD is obvious with focal stricture in distal CBD. Main pancreatic duct is also diffusely dilated. MRCP, magnetic resonance cholangio-pancreaticography; CBD, common bile duct. 상의벽결절들이나점액덩어리들이보이기도하며, 낭성병변내의격벽은잘보이지않거나많은수의격벽이불규칙하게비후된소견을보이기도한다. 또한낭성병변과연관되어고형종괴형성을동반하기도하며이경우에는침윤암종으로변성되었음을시사하는소견이다 (Fig. 3). 낭성병변과주췌관과의연결을확인하는것이다른췌장낭성병변과 IPMN을감별할수있는특이소견인데, 근래연구에의하면고해상도 MDCT나 MRI 등의단면영상이췌관과의연결을확인하는데있어서 ERCP보다예민하고정확한것으로알려져있다 ERCP는 CT, MRI와보완적으로 IPMN에진단적인소견을제시하는데, 주췌관형인경우늘어난주췌관내에차있는점액덩어리나종양결절에의해모양이일정하지않고경계가분명한충만결손들을관찰할수있으며부췌관형의낭성병변들은주췌관과의연결을 ERCP에서쉽게확인할수있고역시내부에점액이나종양 결절에의한충만결손들이보인다. 또한팽대부를통해과다한점액분비와이로인해팽대부입구가돌출되고열려있는소견도진단에특징적이다. 그러나, 큰점액덩어리에의해췌관이막혀있게되면췌관이나병변전체를관찰하지못하는경우도있다 양성과악성 IPMN의감별진단악성 IPMN을시사하는소견으로는, 주췌관이전반적이고다발성으로심하게늘어나고 ( 수치 : 6-15 mm), 부췌관형으로크기가 3-6 cm 이상이거나주췌관확장이동반된종양, 관내충만결손 ( 종양결절 ) 이나병변에고형종괴가있는경우, 병변내석회화, 팽대부의돌출소견, 고령, 당뇨나다른임상증상동반등이있다. 15,21-23 그러나, 악성 IPMN을예측하는소견으로보고된결과들은문헌에따라다소상반되는결과를보이며, 각각의소견마다다른예측도를나타내어영상소견

4 210 The Korean Journal of Gastroenterology: Vol. 52, No. 4, 2008 만으로는양성선종과악성종양을완전하게구별하기어려울수있다. 24 최근에는양성과악성의구분보다침윤성과비침윤성을구분하고자하는시도가있으며, 주췌관형과복합형종양, 주췌관내 6.3 mm 이상의종양결절, 췌장실질내고형종괴를보이는경우에는침윤암종일가능성이높은소견이라보고되고있다. 15,25,26 침윤암종으로변성된악성 IPMN 은원격전이및림프절전이를동반하기도하며, 특히간전이와췌장주위와후복막림프절에전이를보이기도한다. 4. 다른췌장낭성병변과의감별진단 1) 장액낭샘종 (Serous cystadenoma) 전형적미세낭포성 (microcystic) 장액낭샘종은췌장두부에호발하며무수히많은미세낭포와중심섬유반흔에의해특징적인소견을보이나종양의크기가작거나과소낭 (oligocystic) 변이일경우부췌관형 IPMN과감별이어려울수있다. 주췌관과연결은없고점액을생성하지않으며주췌관도확장이없는정상소견을보인다. Table 1. Typical Differential Features between Mucinous Cystic Neoplasm and Branch Duct IPMN Mucinous cystic neoplasm Branch duct IPMN Gender Female predominant M:F 3:2 Age years years Location Pancreatic tail Pancreatic tail >body/tail Tumor margin Well-circumscribed Irregular Peripheral capsule Yes No Gross appearance Orange-like Grape-like Internal structure Cysts in cyst Clustered or cyst by cyst Communication Rare Yes with main duct (though not always seen) Main pancreatic Normal Normal or duct minimally dilated IPMN, intraductal papillary mucinous neoplasm. 2) 점액낭종 (Mucinous cystic neoplasm, MCN) 주췌관의확장이없거나경미한확장만이동반되어있는부췌관형 IPMN 과 MCN의감별이필요한경우가있다. 임상적으로 MCN은거의모두여자에서발생하며호발연령은 30-40대인반면 IPMN 은남 : 여비가 3:2 정도로남자에서더많이발생하고호발연령은 50-60대로더높다. 영상소견에서두종양의감별점은종양이발생한위치, 육안형태, 낭성병변내부딸낭 (daughter cyst) 의형태, 주췌관과의연결유무및주췌관확장여부등의소견으로감별하게된다 (Table 1). 병리적으로는두종양간확연한차이가있는데췌장의 MCN 은경계가매우분명하고변연부에피막 (capsule) 이있으며난소에서발생한점액낭종과상동인종양으로생각되어난소에서와마찬가지로췌장 MCN에서도난소기질 (ovarian stroma) 을가지는것이보통이다. 따라서여자환자에서주췌관확장이없고췌장미부에내부격벽을보이는낭성종괴가있을경우에는 MCN의가능성이높으며남자환자에서췌장두부에있는낭성종괴는부췌관형 IPMN 의가능성이높다. 이외에도고해상도 CT나 MRI로병변과주췌관과의연결을확인하면 IPMN 의진단이확실해진다. 드물게, 병리적으로확진된 MCN 에서도주췌관과의연결이보고된예가있다. 27 3) 만성췌장염에동반된가성낭종및췌관확장주췌관형 IPMN의경우만성췌장염에서국소협착에의해야기된췌관확장과의감별이어려울수있는데 IPMN에서도만성췌장염이동반되기때문이다. 임상적으로만성췌장염으로인한췌관확장이있는환자는상대적으로연령이낮으며대부분알코올섭취의경력을가지고있다. 만성 췌장염으로인한주췌관의확장은미만이고경한정도이며종종췌장의석회화및췌관과연결되는가성낭종들을동반하기도한다. 이경우주췌관형 IPMN과의감별은매우어려우며늘어난췌관이나낭성병변내부에연조직결절이있거나십이지장팽대부가십이지장내로돌출되어있는소견이있다면 IPMN을특이적으로진단할수있다. 13 치료에대한영상검사의역할과지침 1. 양성선종및경계종양 ; 증상없이우연히발견된췌장의양성 IPMN을수술해야하는가? 1990년대까지주췌관또는부췌관형 IPMN은모두악성변성의가능성을고려하여수술절제가시행되었으나 1999 년경일련의연구들에의해부췌관형종양은생물학적으로악성의정도가낮다는결과에따라, 7,28 이종양들에대해서는덜근치적인수술절제나수술없이추적검사와보존조치만으로도가능하다는의견이제기되었다. 8 또한부췌관형 IPMN 환자들을대상으로한연구에서증상이있는환자군에서는악성암의발현빈도가높은반면무증상군에서는침윤암종이없었음이보고되기도하였다. 7,8,10,29 Salvia 등 28 은내시경초음파와비침습적인 MRCP로주췌관확장이나침범이없다고판단되는 89명의부췌관형 IPMN 환자군을 2년동안악성발현을시사하는변화가있는지를전향추적한결과, 대상군의 5.6% 에서병변의크기증가가있어수술절제했을때양성선종또는경계성종양으로진단되었다. 따라서, 수술과관련된유병률을고려하여고령의증상이없

5 Hong HS, et al. Diagnosis of Pancreatic Intraductal Papillary Mucinous Neoplasm 211 는부췌관형 IPMN으로추정되는환자에서는악성발현을시사하는소견이없는한보존적추적관찰이적절할것으로보인다. 2. 수술대상이되는 IPMN 기술한대로, 주췌관형 IPMN에서악성발현의빈도가높다는것은많은문헌에서보고되어있으며주췌관형종양에서도침윤암종으로진단된환자들의 5년생존율은 36-60% 정도로낮은편이다. 5,9 따라서주췌관형및복합형종양에서는적절한기대수명과수술적응증에부합하는환자군에서는수술을일차치료방법으로고려하는것이타당할것이다. 부췌관형 IPMN에서침윤암종의발생빈도는평균 15% (0-31%) 인데전술한대로침윤암종의빈도가높은대상군에서는무증상환자가없는결과를보였다. 9 따라서임상적으로황달이나진행하는당뇨, 복통등의증상이있거나, 영상소견에서악성변성이의심되는부췌관형 IPMN은일차적으로수술절제가치료방법이된다. 3. 수술절제가능성평가와수술부적응대상군수술대상이되는 IPMN의절제가능성평가는고식적인췌장선암종의기준을따르고있으나이를 IPMN에적용했을때의효용성은아직정립되지않은상태이다. 10,25,29 영상소견을통해간이나폐등의원격전이유무, 종괴의국소침범과주변혈관및해부학구조물침범, 림프절전이를평가하게된다. CT를이용하여악성 IPMN에서절제가능성을평가한 Vullierme 등 25 의연구에의하면, CT에의해절제가능한 IPMN을판단하는양성예측도는 100% 였고췌장선암종에서사용되는혈관침범의기준을적용하였을때는절제불가능성이과대평가되었으며, 췌장주위의지방조직침윤소견은선암종에서와달리 IPMN에서는흔하게동반되는췌장염에의한염증때문이므로수술부적응대상이아니라고기술하였다. CT 검사에서수술의부적응이되는소견은췌장주위주요동맥직경을 50% 이상종양이둘러싸거나, 정맥직경을완전히둘러싸서정맥혈전증또는폐쇄가있을경우이고, 종양이정맥을완전히둘러싸침범했더라도정맥폐쇄가없다면외과의사의판단에따라혈관절제가가능하다고하였다. 추적관찰에대한가이드라인 1. 수술환자에서의예후와추적지침대부분의 IPMN은수술적인절제가최적요법이되며종양이완전히절제되었을경우완전치유를기대할수있다. 따라서수술전에악성변성이나췌장실질내로침윤이있 는지를결정하는것이필수적이며이는수술방법결정과수술후예후판단에매우중요하다. 30 일본췌장학회에의해수행된다기관후향연구에의하면 IPMN 환자에서 5년생존율은선종과비침윤상피내암종에서는 %, 경미한침윤암에서는 89%, 그리고침윤암종에서는 57.7% 로보고되었다. 31 최초종양절제후의추적검사기간에대해서는다소논란이있으나 Tanaka 등 9 에의하면수술에의한최종병리진단이비침윤 IPMN로진단된경우에는 12개월간격이, 침윤종양의경우에는 6개월간격의추적이적절하다고하였다. 2. 비수술환자에서보존적추적법 Sai 등 32 에의한보고에서는악성의소견이없는부췌관형 IPMN 환자에서 MRI 검사를이용하여평균 55개월동안추적관찰하였을경우 23명중 22명의환자에서종양의변화가없음을관찰하고이러한환자군에서는세밀한추적관찰이치료법으로적절하다고주장한바있다. Irie 등 33 에의한연구에서는 12개월이상의추적검사기간동안, 35예의부췌관형 IPMN 중 7예에서만크기가증가한소견이보였고, 이중주췌관확장이나내부충만결손이없는 29예에서는단한개의종양만이크기증가를보였음을보고하였다. 따라서, 임상적으로증상이없고주췌관확장이나내부종양결절등의악성변성의증거가없는양성부췌관형 IPMN에서는추적검사가일차적으로권유되며이외변성의소견을동반하거나주췌관형또는복합형종양의경우수술을우선적으로고려해야할것으로생각한다. 수술을하지않고일차적으로추적검사만을하게되는양성 IPMN의검사간격은병변의크기에따라결정되며, 10 mm 이하의종양에서는 1년에한번, mm 크기에서는 6-12개월간격의추적검사가, 20 mm 이상의종양일경우 3-6개월간격의추적검사가권유된다 재발환자에서지침 IPMN이발생한췌관은잠재적으로다발종양발생의가능성이높아질수있어, 췌관의모든부위에서 IPMN이재발할위험이있다는가설이주장되어있지만, 6,34 정확한위험도나발생비율은아직정립되어있지않다. Schnelldorfer 등 35 에의하면, IPMN으로수술을시행받은환자에서침윤암종으로진단된환자들에서는 58% 가, 선종또는상피내암종환자들에서는 8% 에서수술후추적검사에서종양재발이발견되었다. 수술전상피내암종은침윤암종으로재발하였고수술전선종이었던증례들은재발시침윤암이없었다. 재발한종양에대한치료지침도일반적으로동일하여악성변성을의심할소견이없을경우는일단추적검사를하게된다.

6 212 대한소화기학회지 : 제 52 권제 4 호, 2008 결론췌장의 IPMN은양성에서악성으로변화해가는병리양상을가지는종양이므로침범범위의정확한평가와악성변성유무의판단이환자의치료결정에매우중요하고, 이를위해 CT와 MRI 등의비침습적인영상의학검사의중요성이높아지게되었다. CT와 MRI는낭성병변과주췌관과의연결여부나 IPMN과다른낭성질환과의감별, IPMN이의심되는병변에서의악성을시사하는벽내결절이나주변침범여부를판정함으로써, 종양의정확한병기결정, 절제가능성평가및치료방법의선택에지침을제시할수있고더나아가환자의진단과치료향상에기여하리라고본다. 참고문헌 1. Ohhashi K, Murakami Y, Maruyama M, et al. Four cases of mucous secreting pancreatic cancer. Prog Dig Endosc 1982; 20: Kloppel G, Solcia E, Longnecker DS, Capellac C, Sobin LH. Histological typing of tumours of the exocrine pancreas. In: WHO International histological classification of tumours, 2nd ed. Berlin, Germany: Springer, 1996: Longnecker D, Adler G, Hruban RH, Klopper G. Intraductal papillary-mucinous neoplasms of the pancreas. In: Hamolton SR, Aaltonen LA, eds. WHO classification of tumors of the digestive system. Lyon, France: IARC Press, 2000: Maire F, Hammel P, Terris B, et al. Prognosis of malignant intraductal papillary mucinous tumours of the pancreas after surgical resection. Comparison with pancreatic ductal adenocarcinoma. Gut 2002;51: Sohn TA, Yeo CJ, Cameron JL, et al. Intraductal papillary mucinous neoplasms of the pancreas: an updated experience. Ann Surg 2004;239: Klimstra DS. Cystic, mucin-producing neoplasms of the pancreas: the distinguishing features of mucinous cystic neoplasms and intraductal papillary mucinous neoplasms. Semin Diagn Pathol 2005;22: Kobari M, Egawa S, Shibuya K, et al. Intraductal papillary mucinous tumors of the pancreas comprise 2 clinical subtypes: differences in clinical characteristics and surgical management. Arch Surg 1999;134: Terris B, Ponsot P, Paye F, et al. Intraductal papillary mucinous tumors of the pancreas confined to secondary ducts show less aggressive pathologic features as compared with those involving the main pancreatic duct. Am J Surg Pathol 2000;24: Tanaka M, Chari S, Adsay V, et al. International consensus guidelines for management of intraductal papillary mucinous neoplasms and mucinous cystic neoplasms of the pancreas. Pancreatology 2006;6: Doi R, Fujimoto K, Wada M, Imamura M. Surgical management of intraductal papillary mucinous tumor of the pancreas. Surgery 2002;132: Baba T, Yamaguchi T, Ishihara T, et al. Distinguishing benign from malignant intraductal papillary mucinous tumors of the pancreas by imaging techniques. Pancreas 2004;29: Chiu SS, Lim JH, Lee WJ, et al. Intraductal papillary mucinous tumour of the pancreas: differentiation of malignancy and benignancy by CT. Clin Radiol 2006;61: Taouli B, Vilgrain V, O'Toole D, Vullierme MP, Terris B, Menu Y. Intraductal papillary mucinous tumors of the pancreas: features with multimodality imaging. J Comput Assist Tomogr 2002;26: Sahani DV, Kadavigere R, Blake M, Fernandez-Del Castillo C, Lauwers GY, Hahn PF. Intraductal papillary mucinous neoplasm of pancreas: multi-detector row CT with 2D curved reformations--correlation with MRCP. Radiology 2006;238: Ogawa H, Itoh S, Ikeda M, Suzuki K, Naganawa S. Intraductal papillary mucinous neoplasm of the pancreas: assessment of the likelihood of invasiveness with multisection CT. Radiology 2008;248: Takada A, Itoh S, Suzuki K, et al. Branch duct-type intraductal papillary mucinous tumor: diagnostic value of multiplanar reformatted images in multislice CT. Eur Radiol 2005; 15: Fukukura Y, Fujiyoshi F, Sasaki M, et al. HASTE MR cholangiopancreatography in the evaluation of intraductal papillary-mucinous tumors of the pancreas. J Comput Assist Tomogr 1999;23: Song SJ, Lee JM, Kim YJ, et al. Differentiation of intraductal papillary mucinous neoplasms from other pancreatic cystic masses: comparison of multirow-detector CT and MR imaging using ROC analysis. J Magn Reson Imaging 2007;26: Yamada Y, Mori H, Matsumoto S. Intraductal papillary mucinous neoplasms of the pancreas: correlation of helical CT and dynamic MR imaging features with pathologic findings. Abdom Imaging 2008;33: Peters HE, Vitellas KM. Magnetic resonance cholangiopancreatography (MRCP) of intraductal papillary-mucinous neo-

7 홍혜숙외 1 인. 췌관내유두상점액종양 (IPMN) 의진단 213 plasm (IPMN) of the pancreas: case report. Magn Reson Imaging 2001;19: Fukukura Y, Fujiyoshi F, Sasaki M, Inoue H, Yonezawa S, Nakajo M. Intraductal papillary mucinous tumors of the pancreas: thin-section helical CT findings. AJR Am J Roentgenol 2000;174: Taouli B, Vilgrain V, Vullierme MP, et al. Intraductal papillary mucinous tumors of the pancreas: helical CT with histopathologic correlation. Radiology 2000;217: Irie H, Honda H, Aibe H, et al. MR cholangiopancreatographic differentiation of benign and malignant intraductal mucin-producing tumors of the pancreas. AJR Am J Roentgenol 2000;174: Sugiyama M, Atomi Y. Intraductal papillary mucinous tumors of the pancreas: imaging studies and treatment strategies. Ann Surg 1998;228: Vullierme MP, Giraud-Cohen M, Hammel P, et al. Malignant intraductal papillary mucinous neoplasm of the pancreas: in situ versus invasive carcinoma surgical resectability. Radiology 2007;245: Yamada Y, Mori H, Matsumoto S, Kamei N, Hongo N. Invasive carcinomas derived from intraductal papillary mucinous neoplasms of the pancreas: a long-term follow-up assessment with CT imaging. J Comput Assist Tomogr 2006; 30: Yamao K, Nakamura T, Suzuki T, et al. Endoscopic diagnosis and staging of mucinous cystic neoplasms and intraductal papillary-mucinous tumors. J Hepatobiliary Pancreat Surg 2003;10: Salvia R, Crippa S, Falconi M, et al. Branch-duct intraductal papillary mucinous neoplasms of the pancreas: to operate or not to operate? Gut 2007;56: Matsumoto T, Aramaki M, Yada K, et al. Optimal management of the branch duct type intraductal papillary mucinous neoplasms of the pancreas. J Clin Gastroenterol 2003;36: Kawamoto S, Horton KM, Lawler LP, Hruban RH, Fishman EK. Intraductal papillary mucinous neoplasm of the pancreas: can benign lesions be differentiated from malignant lesions with multidetector CT? Radiographics 2005;25: Suzuki Y, Atomi Y, Sugiyama M, et al. Cystic neoplasm of the pancreas: a Japanese multiinstitutional study of intraductal papillary mucinous tumor and mucinous cystic tumor. Pancreas 2004;28: Sai JK, Suyama M, Kubokawa Y, et al. Management of branch duct-type intraductal papillary mucinous tumor of the pancreas based on magnetic resonance imaging. Abdom Imaging 2003;28: Irie H, Yoshimitsu K, Aibe H, et al. Natural history of pancreatic intraductal papillary mucinous tumor of branch duct type: follow-up study by magnetic resonance cholangiopancreatography. J Comput Assist Tomogr 2004;28: D'Angelica M, Brennan MF, Suriawinata AA, Klimstra D, Conlon KC. Intraductal papillary mucinous neoplasms of the pancreas: an analysis of clinicopathologic features and outcome. Ann Surg 2004;239: Schnelldorfer T, Sarr MG, Nagorney DM, et al. Experience with 208 resections for intraductal papillary mucinous neoplasm of the pancreas. Arch Surg 2008;143: