A case of a mucin-producing bile duct tumor diagnosed over the course of 6 years

We report a case of a mucin-producing intraductal papillary neoplasm of the intrahepatic bile duct (M-IPNB) diagnosed over a period of 6 years. A 64-year-old man underwent follow-up evaluations for an abdominal aortic aneurysm at our hospital. In 2009, a computed tomography (CT) scan revealed a simple hepatic cyst in segment 3 of the liver. Annual CT scans initially showed almost no change in the size or shape of the cyst. The cystic lesion, which measured 5 cm in 2014, had increased to 11 cm by 2015, and a solid component was detected within the cyst. A biliary cystic tumor was suspected and we performed a left lateral hepatectomy. Pathological examination showed that the papillary lesion in the cyst included adenocarcinoma and adenoma components. We diagnosed M-IPNB in 2015. Identification of the solid component of the cyst, as well as an increase in cyst diameter in the image analyses, was critical for diagnosis of M-IPNB.     

Long-term growth of intrahepatic papillary neoplasms: A case report

BACKGROUND Intraductal papillary neoplasm of the bile duct(IPNB) is a type of tumor that presents in the intra-or extrahepatic bile ducts. Cystic-type intrahepatic IPNB often mimics simple liver cysts, making the diagnosis difficult. Because the growth of IPNB is slow, careful follow-up and timely therapeutic intervention is recommended. There are few reports with a follow-up period longer than a decade; thus, we report the case of a patient with an IPNB that grew for over 13 years.CASE SUMMARY A 65-year-old man was diagnosed, 13 years prior with a cystic hepatic tumor with abnormal imaging findings. The targeted tumor biopsy results showed no malignancy. Biannual follow-up examinations were performed because of the potential for malignancy. The cystic lesions showed gradual enlargement over 11 years and a 4 mm papillary proliferation appeared on the cyst wall, which is compatible with IPNB. The tumor was observed for another 2 years because of the patient's wishes. The imaging findings showed enlargement to 8 mm and a new 9 mm papillary proliferation of the cystic tumor. Contrast-enhanced ultrasonography showed hyperenhancement during the arterial phase in both cyst walls, indicating intraductal tumor progression in both tumors. Thus, liver segment 8 subsegmentectomy was performed. The pathological findings indicated that the tumors contained mucin, and high-grade atypia was observed in the papillary lesions, showing IPNB.CONCLUSION The development of IPNB should be monitored in patients with cystic lesions and ultrasonography are useful tool for the evaluation.     

Biliary cystadenocarcinoma followed up as benign cystadenoma for 10 years

We describe a case of biliary cystadenocarcinoma that showed a longterm clinical course. A 69-year-old Japanese man was admitted to our hospital because of abdominal discomfort. The patient had been diagnosed with benign cystadenoma of the liver at another hospital in 1987 and had been followed up for 10 years. Abdominal ultrasonography (US) and computed tomography (CT) scan demonstrated a unilocular cystic lesion, which included multiple conspicuous papillary protrusions in the left hepatic lobe. Left lateral segmentectomy was performed, and intraoperative cholangiography revealed a communication between the cystic tumor and intrahepatic bile duct. The tumor contained clear mucinous fluid and enfolded multiple yellowish papillary projections on the cystic wall. Histological examination showed the tumor to be biliary cystadenocarcinoma. The patient is doing well 4 years after the operation.     

Intracystic hemorrhage of a simple liver cyst mimicking a biliary cystadenocarcinoma

Simple liver cysts are rarely complicated by intracystic hemorrhage. We encountered a case of simple liver cyst that was morphologically similar to biliary cystadenocarcinoma, which was complicated by asymptomatic intracystic hemorrhage and successfully treated by right lobectomy. A large cystic lesion of the liver was detected in a 57-year-old woman during a mass screening health check. Abdominal ultrasonography (US) revealed that the cystic lesion, containing many hyperechoic papillary structures, occupied almost the entire region of the right hepatic lobe. In addition, a round mural nodule, measuring approximately 5 cm in diameter, was detected in the cystic wall. Abdominal computed tomography (CT) revealed that the inner part of the cystic lesion showed homogeneous low density, but CT did not show the round nodule detected by US. On T1-weighted sequence of magnetic resonance imaging (MRI), the lesion showed homogeneous high signals, together with a low-signal tumorous lesion in the cystic wall. T2-weighted sequence of MRI showed unhomogeneous high signals, together with high signals in the tumorous part. These findings did not exclude the possibility of a malignant cystic tumor, such as biliary cystadenocarcinoma. Therefore, right lobectomy was performed. Histological examinations of resected tissue specimens revealed that the lesion was a liver cyst containing a large amount of blood clot, and that the tumorous lesion detected by US and MRI was a large mass of blood clot which was partly liquefied. This case indicates the diagnostic importance of the morphological discordance between CT and US or MRI findings for liver cyst containing a large amount of blood clot. Received: May 7, 2001 / Accepted: December 27, 2001 Reprint requests to: Y. Kitajima     

Thirteen cases of intrahepatic biliary cystadenoma and cystadenocarcinoma: a single center experience]

BACKGROUND/AIMS: Biliary cystadenoma (BCA) and biliary cystadenocarcinoma (BCACa) are rare cystic neoplasms that usually arise from the liver. We reviewed the clinicopathologic and radiologic findings of 13 cases of intrahepatic biliary cystic neoplasms. METHODS: Seven patients with BCA and 6 patients with BCACa which were pathologically proven within past 10 years were included in this retrospective study. RESULTS: BCA (7 of 7) was more common in female compared to BCACa (4 of 6). Mean age at diagnosis was 53.4 years (BCA) and 58.5 years (BCACa). Abdominal pain (54%) was the most common presenting symptom. Eleven patients (61.5%) exhibited normal liver function profiles and 5 patients (38%) showed elevated levels of serum CA19-9 levels (mean 894.2 U/mL, range: 78.7-2,080). Mean size of tumor was 11.7 cm (range: 5-15). Most frequent radiologic finding was a single cystic mass with septation. BCACa tended to have intracystic solid portion. The cut surface revealed a unilocular or multilocular cystic mass with mucinous contents. Complete surgical excision was done in 12 patients. After the complete resection, recurrence was observed in 1 case of BCACa. CONCLUSIONS: The possibility of biliary cystic neoplasm should be suspected when an intrahepatic cystic lesion with multiseptation or solid portion is noted on imaging study. In addition, complete excision for definite diagnosis and treatment need to be performed.     

Intrahepatic biliary papilloma morphologically similar to biliary cystadenoma

A 37-year-old man presented complaining of epigastralgia. Abdominal ultrasonography revealed the presence of a papillary tumor (9 mm in diameter) in the cystic lesion (18 mm in diameter) in hepatic segment 4, which was accompanied by mild intrahepatic bile duct dilatation. Although abdominal computed tomography also showed the cystic lesion, it did not show papillary tumors inside the lesion. Endoscopic retrograde cholangiography showed the communication between the cystic lesion and the left hepatic duct. In addition, mucus was observed in the common bile duct. When transpapillary intraductal ultrasonography was performed through the left hepatic duct using a fine ultrasonic probe, a hyperechoic papillary and lobulated tumor was clearly shown in the cystic lesion. The wall of the cyst was smooth and there was no sign of tumor infiltration. Based on these findings, biliary cystadenoma was diagnosed and an extended left lobectomy was carried out. However, pathological findings postoperatively revealed that the lesion was a localized biliary papilloma, developing and extending to the intrahepatic duct. This case is rare and there have been no published reports describing a biliary papilloma morphologically similar to biliary cystadenoma.     

Rare biliary cystic tumors: a case series of biliary cystadenomas and cystadenocarcinoma

Cystic lesions of the liver are common and a major proportion is formed by parasitic cysts and simple cysts. Biliary cystic tumors (BCTs), namely biliary cystadenoma (BCA) and biliary cystadenocarcinoma (BCAC), are rare tumors which usually arise from the intrahepatic biliary tree. BCAs have malignant potential and are difficult to differentiate from BCAC pre-operatively on radiological imaging. Here we have presented 4 patients with BCTs and reviewed the literature pertaining to them.The data of four patients with BCA/BCAC diagnosed and treated at our institute were retrieved from our database and records were reviewed for age, sex, history, imaging, surgery, pathology and follow-up. Mean age of the patients was 53.5 years (range 30-71 years). Two male and two female patients presented with abdominal pain, of which one male patient had pancreatitis at diagnosis. Characteristic features were seen on pre-operative imaging (cystic lesions with internal septations) and biliary communication was identified in the patient with pancreatitis. Three patients were diagnosed with a BCA on final histology, while one patient had a BCAC. Following surgical resection, all the patients are asymptomatic and disease free with a mean follow-up of 24 months (range 10-40 months). In conclusion, BCTs should be suspected in the presence of a well-encapsulated, cystic hepatic lesion with internal septations. Although pre-operative distinction between BCA and BCAC is difficult, the lesion, whenever possible, should be completely resected as long-term outcomes are good, especially with BCA.     

Intraductal mucinous tumors occurring simultaneously in the liver and pancreas

A case of simultaneous intraductal mucinous tumors of the liver and pancreas in a 67-year-old man is described. Abdominal ultrasonography and computed tomography (CT) revealed the presence of cystic lesions with intraluminal septae both in the caudate lobe of the liver and in the uncinate process of the pancreas; these cystic lesions communicated with the hepatic duct and pancreatic duct, respectively. Mucin retention was observed in the cysts, and cholestasis was induced by mucin secretion into the common bile duct. The lesions were resected by left hepatic lobectomy with caudate lobectomy, and segmental pancreatectomy. Both lesions were multilocular cystic tumors with no papillary projections or focal mass effect in their walls. Histologically, both cystic lesions were a mixture of hyperplasia and adenoma lined by low papillary columnar epithelium. There were no cellular or histological features to suggest malignant change. The fibrous intratumor interstitium lacked any mesenchymal or ovarian-like stroma. The hepatic lesion was considered to be of a similar nature to intraductal papillary mucinous tumor (IPMT) of the pancreas. However, the two lesions occurred simultaneously in the liver and pancreas. This case is of interest in regard to the diagnosis and management of mucinous hepatopancreatobiliary lesions. Received: March 16, 2001 / Accepted: September 14, 2001     

Congenital cystic diseases of the intra and extrahepatic bile ducts

Congenital cystic lesions of bile ducts may affect intra or extrahepatic bile ducts. Intrahepatic lesions include five entities: congenital hepatic fibrosis, Caroli's syndrome, von Meyenburg complexes, simple cyst of the liver and polycystic liver disease. Congenital hepatic fibrosis and von Meyenburg complexes are secondary to ductal plate malformation affecting the smallest intrahepatic bile ducts. Cystic dilatations are of small size and only detected at histological examination of the liver. They have few clinical consequences. In congenital hepatic fibrosis, the main manifestations result from portal hypertension. Caroli's syndrome is secondary to ductal plate malformation affecting the largest intrahepatic bile ducts. Cystic dilatations are macroscopic and responsible for cholangitis and may lead to biliary stones and carcinoma which develop within cystic dilatations. Caroli's syndrome may be or not associated with congenital hepatic fibrosis. In case of associated congenital hepatic fibrosis, portal hypertension is present. Simple cyst of the liver and polycystic liver disease are characterized by cystic dilatations which, by contrast to the preceding entities, do not communicate with the rest of biliary tree. As a result, they have only few clinical consequences. In congenital hepatic fibrosis and polycystic liver disease, renal abnormalities are frequently observed. They correspond to renal malformations associated with biliary malformations. In congenital hepatic fibrosis, renal lesions are characterized by ectatic collecting tubules which are present in two thirds of the cases and transmitted as an autosomal recessive trait. In polycystic liver disease, renal lesions are characterized by polycystic disease which is present in half of the cases and transmitted as an autosomal dominant trait. Congenital cystic lesions of extrahepatic bile ducts consist of choledochal cyst, which is secondary to malformation of the pancreato-biliary ductal junction. The major risk of choledochal cyst is the development of intracystic cancer, the prevention of which is total surgical resection of the cyst.     

消化道肿瘤CT动脉造影分析83例

目的:总结消化道肿瘤CT动脉造影情况,探讨CT动脉造影诊断消化系统疾病价值．方法:选CT等其它法已明确和未明确的消化道肿瘤性患者83例,采用Seldinger技术经股动脉插管,行CT动脉造影,肝脏肿瘤同时行CT门脉造影．分析影像所见并与超声、CT、MRI等比较,结合临床探讨CT动脉造影诊断消化道肿瘤价值．结果:CT等已明确诊断肝癌的42例患者中,35例新发现卫星灶或周边小灶．14例临床疑肝癌,CT、彩超无异常,通过CT动脉造影10例诊断早期肝癌,2例弥漫性肝癌,2例正常．10例结肠癌患者,CT等方法未见肝转移,CT动脉造影发现7例有早期肝转移．7例肝占位待查患者,6例符合肝癌,1例符合血管瘤．6例疑胆囊癌患者,4例确诊胆囊癌．2 例胰腺癌患者,CT动脉造影显示明显强化．2例胃癌患者可清楚显示病变范围、血运程度及与周围脏器关系．结论:CT动脉造影可发现超声、CT等其它法不能发现的卫星小灶或肝内其它小癌灶,对诊断早期肝癌特殊敏感,对显示肝内早期转移灶和定性诊断优于其它影像技术,CT动脉造影更能准确显示病灶血运情况、病变范围及与邻近脏器关系．     

Cystic tumors of the liver： A practical approach

Biliary cyst tumors （cystadenoma and cystadenocarcinoma） are an indication for liver resection. They account for only 5% of all solitary cystic lesions of the liver, but differential diagnosis with multiloculated or complicated biliary cysts, atypical hemangiomas, hamartomas and lymphangiomas may be difficult. The most frequent challenge is to differentiate biliary cyst tumors from hemorrhagic cysts. Computerized tomography （CT） and magnetic resonance imaging （MRI） are often not diagnostic and in these cases fine needle aspiration （FNA） is used to confirm the presence of atypical biliary cells. FNA, however, lacks adequate sensitivity and specificity and should always be used in conjunction with imaging. Pre-operative differentiation of cystadenoma from cystadenocarcinoma is impossible and surgery must be performed if a biliary cyst tumor is suspected. When multiple cystic lesions are observed throughout the liver parenchyma, it is important to exclude liver metastasis, of which colonic cancer is the most common primary site. Multiple biliary hamartomas （von Meyenburg complex） can appear as a mixture of solid and cystic lesions and can be confused with cystic metastasis. Strong and uniform T2 hyperintensity on MRI is usually diagnostic, but occasionally a percutaneous biopsy may be required.     

Hydatid cyst of the liver: a case report and literature review

Taiwan is nearly free from hydatid disease. We report a case of hydatid cyst of the liver in a 37-year-old man who originally lived in India and had migrated to Taiwan 2 years earlier. He presented with right upper quadrant pain and intermittent low-grade fever. Both sonography and computed tomography (CT) demonstrated a cystic lesion with vesicles at its periphery in segments 6 and 7 of the liver. A hydatid cyst was diagnosed. The patient underwent radical excision of the cyst with total removal without opening the wall. He also received pre- and postoperative oral mebendazole. Pathology showed a hydatid cyst consisting of three layers: the inner single nucleated geminal layer, the middle acellular laminated layer, and the outer pericyst originating from inflammatory and hepatic cells. This case highlights that accurate preoperative diagnosis of hydatid disease can be made from personal history, typical sonography and CT study in non-endemic areas.     

A resected case of combined hepatocellular carcinoma and cholangiocarcinoma associated with cystic formation

Combined hepatocellular carcinoma and cholangiocarcinoma is a rare tumor. In addition, both hepatocellular carcinoma and cholangiocarcinoma are rarely associated with cystic lesions. We herein present a 62-year-old Japanese woman with combined hepatocellular carcinoma and cholangiocarcinoma which was associated with a rapidly enlarging cystic lesion. Both abdominal ultrasonography and computed tomography revealed a cyst with a solid portion in the left hepatic lobe. A partial hepatectomy was performed on the basis of a tentative diagnosis of a cystadenocarcinoma of the liver, while the diagnosis based on immunohistochemical studies was combined hepatocellular carcinoma and cholangiocarcinoma with cystic formation. The patient died of tumor recurrence, such as intrahepatic metastases and extensive lymph node metastases, 6 months after the operation. The prognosis of this entity, which has never been reported in the English medical literature and is difficult to preoperatively differentiate from hepatic cystadenocarcinoma, therefore seems to be extremely poor.     

影像学检查评估TACE治疗的原发性肝癌患者术后残余肿瘤活性价值研究

目的 探讨超声(US)、电子计算机断层扫描(CT)和磁共振成像(MRI)检查评估原发性肝癌(PLC)患者在经导管动脉栓塞化疗(TACE)治疗术后肿瘤活性的价值。方法 2015年3月~2019年1月我院放射介入科行TACE治疗的60例PLC患者,术后3~5周行 US、CT、MRI及数字减影血管造影(DSA)检查。以DSA检查结果为金标准,评判US、CT和MRI对残余病灶活性检出率的差异。结果 在60例PLC患者,术后DSA 检测出72个病灶,以此为金标准,结果MRI检出65个(90.3%)病灶,US检出34个(47.2%)病灶,CT检出55个(76.4%)病灶,提示US检出率最低(P<0.05);MRI检出的灵敏度、特异度和准确性分别为87.5%、95.8%和83.3%,而US检出分别为41.6%、97.9%和39.5%,CT检出分别为75.0%、89.5%和64.5%,提示MRI检出的灵敏度和准确性显著高于US或CT检查(P＜0.05),而三种方法检出的特异度无显著性差异(P>0.05)。结论 介入手术治疗后,需采用影像学方法检查及时评估残余肿瘤活性,以决定后期治疗,以MRI检查的效能最好,但其费用可能较高。     

INTRABILIARY OBSTRUCTION DUE TO RUPTURED HEPATIC HYDATID CYST: EVALUATION WITH COMPUTED TOMOGRAPHY AND MAGNETIC RESONANCE IMAGING

Background: One of the most common and very serious complications of a hepatic echinococcal cyst is the intrabiliary rupture of the cyst and, in some cases, the obstruction of the biliary system. The effectiveness of computed tomography (CT) and magnetic resonance imaging (MRI) was evaluated for the preoperative diagnosis of hydatid cyst into the biliary tree. Methods: The techniques of CT, MRI and magnetic resonance (MR) cholangiography were used to examine nine cases of intrabiliary rupture of the hepatic hydatid cyst. The confirmation of the diagnosis was made at surgery in four cases and with endoscopic retrograde cholangiopancreatography in five cases. Results: By using CT and MRI, the intrabiliary rupture of an echinococcal cyst was diagnosed readily and accurately in all cases. In eight cases, we found a dilated intrahepatic biliary vessel near the ruptured echinococcal cyst, without any evidence of communication between the cyst and the biliary system. Also in six cases there was an abnormal configuration of the terminal part of the biliary radicle. Conclusion: This study suggests that a dilated biliary radicle with conical configuration of its end‐part and in close proximity with hydatid cyst is strong evidence of previous or active rupture of hydatid cyst into the biliary system. A combined study of CT or MRI and MR cholangiography is mandatory for proper preoperative evaluation of the intrabiliary rupture of hepatic hydatid cyst.     

钆塞酸二钠增强磁共振扫描诊断肝脏局灶性病变研究*

目的 通过与手术后组织病理学诊断结果比较,观察钆塞酸二钠（Gd-EOB-DTPA）增强磁共振成像（MRI）对肝脏局灶性病变（FLL）的诊断价值。方法 我院收治的FLL患者68例,接受Gd-EOB-DTPA增强MRI检查,与术后组织病理学诊断比较检查结果的正确性。结果 68例FLL患者经术后组织病理学检查诊断为肝细胞癌36例,肝内胆管细胞癌6例,混合型肝癌8例,肝局灶性结节性增生12例,肝血管平滑肌脂肪瘤4例,非FLL 2例,而Gd-EOB-DTPA增强MRI诊断FLL 64例,其中肝细胞癌37例,肝内胆管细胞癌7例,混合型肝癌4例,肝局灶性结节性增生14例,肝血管平滑肌脂肪瘤2例,非FLL 4例。增强MRI诊断FLL的Kappa值为0.7,其灵敏度为97.1%,特异度为100.0%,阳性预测值为100.0%,阴性预测值为50.0%。结论 采取Gd-EOB-DTPA增强MRI检查对FLL诊断具有较高的灵敏度和特异度,临床应重视其诊断价值。     

Traumatic rupture of a type Ⅳ a choledochal cyst in an adult male

Choledochal cyst (CC) is a rare, congenital anomaly of the bile ducts. We describe a 26-year-old male patient who was transferred to our hospital with a reported traumatic rupture of cystic liver lesions following a fall. At the time of injury, the patient experienced severe abdominal pain. He was found to have peritonitis and abdominal hemorrhage, which is quite rare. Laparot-omy revealed 3000 mL fluid consisting of a mixture of blood, bile and inflammatory effusion in the peritoneal cavity. The liver, gallbladder, spleen, stomach, duo-denum, small intestine, and colon appeared normal. A large cystic mass was discovered near the porta hepatis. This mass, which connected to the hepatic bifurcation and gallbladder had a 5 cm rupture in the right wall with active arterial bleeding. Abdominal com-puted tomography (CT) and emergency laparotomy revealed rupture of a huge type Ⅳa CC. The patient was successfully managed by primary cyst excision, cholecystectomy, and Roux-en-Y end-to-side hepatico-jejunostomy reconstruction. The postoperative course was uneventful and the patient was discharged on the 12 th day of hospitalization. Four weeks after surgery,abdominal CT scan showed pneumatosis in the intra-hepatic bile duct, and intrahepatic dilatation which decreased following adequate biliary drainage. The patient has remained well in the close follow-up period for 9 mo.     

EUS for detection of the hepatocellular carcinoma: results of a prospective study

BACKGROUND: Early detection of hepatocellular carcinoma (HCC) and accurate determination of the number of lesions are critical in determining eligibility for liver transplantation or resection. Current diagnostic modalities (CT and magnetic resonance imaging [MRI]) often miss small lesions. OBJECTIVE: To compare the accuracy of the EUS with CT for the detection of primary tumors of the liver. DESIGN: Prospective single-center study. SETTING: Academic medical center. PATIENTS: Subjects at high risk of HCC (hepatitis B, hepatitis C, or alcoholic cirrhosis) were enrolled. INTERVENTIONS: US, CT, MRI, and EUS examinations of the liver were performed. Liver lesions identified during EUS underwent EUS-guided FNA (EUS-FNA). RESULTS: Seventeen patients were enrolled in the study. Nine of these patients had liver tumors (HCC, 8; cholangiocarcinoma, 1). EUS-FNA established a tissue diagnosis in 8 of the 9 cases. The diagnostic accuracy of US, CT, MRI, and EUS/EUS-FNA were 38%, 69%, 92%, and 94%, respectively. EUS detected a significantly higher number of nodular lesions than US (P = .03), CT (P = .002), and MRI (P = .04). For HCC lesions, a trend was observed in favor of EUS for the detection of more lesions than US (8 vs 2; P = .06) and CT (20 vs 8; P = .06). No complications were observed as a result of EUS-FNA. LIMITATIONS: Small sample size. CONCLUSIONS: EUS-FNA is a safe and accurate test for the diagnosis of HCC. EUS increases the accuracy of intrahepatic staging of the HCC by delineation of lesions, which are missed by CT and MRI. We recommend EUS for suspected HCC, particularly in cases that are being considered for liver transplantation.     

Image-diagnostic features of mature cystic teratomas of the pancreas: report on two cases difficult to diagnose preoperatively

This report documents the findings of two rare cases of mature cystic teratoma of the pancreas. Although they could not be diagnosed preoperatively, our retrospective report suggests that the combined diagnosis of ultrasonography (US), enhanced computed tomography (CT), and magnetic resonance cholangiopancreatography (MRCP) might allow differentiation from other cystic lesions such as mucinous cystic tumors (MCTs) and intraductal papillary–mucinous tumors (IPMTs). Since the cystic teratomas were both filled with keratinous and sebaceous material, they were echogenic, appearing as solid masses on US. Enhanced CT showed their cystic nature, with values slightly higher than water, and MRCP revealed defects of internal signals.     

Intraductal papillary mucinous tumor of the pancreas: computerized tomography and magnetic resonance imaging features

The aim of this study was to analyze the computerized tomography (CT) and magnetic resonance imaging (MRI) features of intraductal papillary mucinous tumor (IPMT) of the pancreas. The cases of eight patients with pathologically proven IPMT (1 papillary hyperplasia, 7 adenocarcinoma) of the pancreas were retrospectively reviewed. There were five men and three women with ages ranging from 42 to 82 years. Imaging studies included six thin-section dynamic CT scans, seven MRI scans, one MR cholangiopancreatography scan, and two endoscopic retrograde cholangiopancreatography scans. There was only one benign IPMT, which presented as a unilocular cyst in the pancreatic body with no mural nodules and no dilatation of the main pancreatic duct (MPD). All seven patients with malignant IPMT had multilocular cysts with papillary projections in the pancreatic head and/or uncinate process accompanied by dilated MPD (5 diffuse, 2 segmental). Communication between the cystic lesions and the MPD were evident in all seven patients. One patient had small mural nodules in the branch ducts of the pancreatic body and five had a bulging papilla with a patulous orifice. A mass effect resulting in biliary obstruction was shown in one patient. One patient had a ruptured cyst with mucin leakage into the right anterior pararenal space following sono-guided aspiration. In conclusion, the main imaging feature of IPMT in our patients was a multilocular cyst with papillary projections located in the pancreatic head and uncinate process. Although CT and MRI cannot differentiate mucin content from pancreatic juice, communication between the cystic lesion and the dilated MPD and a bulging papilla with a patulous orifice are characteristics of IPMT.