Intraductal papillary mucinous tumors and mucinous cystic tumors of the pancreas: imaging

Most cystic lesions of the pancreas are nonneoplastic and inflammatory in nature. However, approximately 5%–15% of cystic pancreatic masses may be neoplastic. Among the cystic neoplasms are the mucin-producing tumors, both the intraductal papillary mucinous neoplasms and the mucinous cystic neoplasms. Their imaging features on contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) can assist in the differentiation of these lesions. The imaging findings of both intraductal papillary mucinous neoplasm and mucinous cystic neoplasm are reviewed with attention to CT and MRI.     

Intraductal papillary mucinous neoplasms and other pancreatic cystic lesions

Pancreatic cystic neoplasms are being increasingly recognized, even in the absence of symptoms, in large part, due to markedly improved imaging modalities such as magnetic resonance imaging (MRI)/magnetic resonance cholangio pancreatography (MRCP) and computer tomography (CT) scanning. During the past 2 decades, better imaging of these cystic lesions has resulted in definition of different types, including pancreatic intraductal papillary mucinous neoplasms (IPMN). While IPMN represent only a distinct minority of all pancreatic cancers, they appear to be a relatively frequent neoplastic form of pancreatic cystic neoplasm. Moreover, IPMN have a much better outcome and prognosis compared to pancreatic ductal adenocarcinomas. Therefore, recognition of this entity is exceedingly important for the clinician involved in diagnosis and further evaluation of a potentially curable form of pancreatic cancer.     

Intraductal papillary mucinous neoplasms and other pancreatic cystic lesions

Pancreatic cystic neoplasms are being increasingly recognized, even in the absence of symptoms, in large part, due to markedly improved imaging modalities such as magnetic resonance imaging （MRI）/magnetic resonance cholangio pancreatography （MRCP） and computer tomography （CT） scanning. During the past 2 decades, better imaging of these cystic lesions has resulted in definition of different types, including pancreatic intraductal papillary mucinous neoplasms （IPMN）. While IPMN represent only a distinct minority of all pancreatic cancers, they appear to be a relatively frequent neoplastic form of pancreatic cystic neoplasm. Moreover, IPMN have a much better outcome and prognosis compared to pancreatic ductal adenocarcinomas. Therefore, recognition of this entity is exceedingly important for the clinician involved in diagnosis and further evaluation of a potentially curable form of pancreatic cancer.     

Usefulness of Intraductal Ultrasonography (IDUS) for Diagnosing Mucin-producing Pancreatic Tumors

Abstract: While it is very important to detect protruded lesions in order to determine the optimal treatment modality for mucin-producing tumors of the pancreas (MPT), it can be very difficult to discriminate between mucinous substance and tumor. Intraductal ultrasonography (IDUS) (2.0 mm diameter, 15 or 20 MHz) was performed in five MPT cases. The sizes of the tumors were 2, 5, 12, 12 and 30 mm. Histological findings of the resected specimens demonstrated adenocarcinoma in two cases, adenoma in one, and hyperplasia in one. IDUS visualized all tumors, i. e. the visualization rate was 100%. The visualization rate for US and CT was 40% with 12 and 30 mm tumors, and that for EUS was 60% with 2, 12, and 30 mm tumors. We found IDUS to be a very useful method for visualizing small protruded lesions in MPT.     

Macrocystic Serous Cystadenoma of the Pancreas

Abstract: The case of a 61 -year-old man with macrocystic serous cystadenoma of the pancreas is reported. Abdominal ultrasonography and computerized tomography showed a multilocular cystic lesion in the body of the pancreas. The major cysts ranged in size from more than 2.0 cm up to 6.0 crn. Endoscopic ultrasonography (EUS) showed a few small cysts in addition to the large cysts. The preoperative diagnosis was either mucinous cystic tumor or congenital cyst of the pancreas and tumor enucleation was performed. Histological examination revealed serous cystadenoma of the pancreas with macrocysts. Detecting small cysts with EUS may be useful for distinguishing this unusual tumor from mucinous cystic tumors.     

Chronic asymptomatic pseudocyst with sludge aggregates masquerading as mucinous cystic neoplasm of the pancreas

Pseudocyst of the pancreas is sometimes difficult to distinguish from mucinous cystic neoplasm of the pancreas. A 37-year-old asymptomatic Japanese man was diagnosed with hypertension. He had a 20-years history of habitual drinking of alcohol, but no history of pancreatitis or abdominal trauma. During examinations to ascertain the cause of hypertension, ultrasonography and computed tomography incidentally demonstrated a huge cyst in the head of the pancreas. Laboratory data were within normal limits, including serum levels of amylase, carcinoembryonic antigen, and carbohydrate antigen 19-9. Imaging studies showed a huge unilocular cyst, measuring 7 cm, in the head-to-body of the pancreas, and two small unilocular cysts, measuring 1.4 and 1.5 cm, in the tail and head of the pancreas, respectively. A mural nodule was suspected in the largest cyst. Endoscopic retrograde cholangiopancreatography demonstrated communication of the main pancreatic duct with the two small cysts in the head and tail of the pancreas but not with the huge cyst. There were no ductal changes suggesting chronic pancreatitis. Laparotomy was performed under the tentative diagnosis of potentially malignant mucinous cystic neoplasms of the pancreas. However, inflammatory adhesion was dense around the pancreas and the mural nodule suspected preoperatively was found to be sludge aggregates in a pseudocyst. The diagnosis of an intraoperative frozen section of the cyst wall was pseudocyst of the pancreas. Cystojejunostomy was performed. We report this case because the pre-operative diagnosis was mucinous cystic neoplasm of the pancreas, but the diagnosis changed with careful intraoperative examinations, to pseudocyst of the pancreas. We discuss the differential diagnosis of the two conditions. (Received Oct. 1, 1997; accepted Jan. 23, 1998)     

Diagnosis and management of relapsing pancreatitis associated with cystic neoplasms of the pancreas

One of the most important causes of relapsing pancreatitis is a cystic neoplasm of the pancreas. These low grade malignancies may cause pancreatitis by obstructing or communicating with a pancreatic duct. Patients with relapsing pancreatitis and a focal fluid fluid collection should be investigated for the possibility of a mucinous cystic neoplasm. Cross sectional imaging can provide a diagnosis with the imaging findings of a low attenuation cystic lesion containing mural calcification （CT scanning） or a lobular T2 enhancing lesion （MRCP）. Endoscopic ultrasound can provide more detailed imaging with the ability to guide fine needle aspiration of the cyst fluid. Cyst fluid analysis can provide a diagnosis of a mucinous cystic lesion with the combination of cytology （mucinous epithelium）, elevated carcinoembryonic antigen （CEA）, and the presence of DNA mutations. Management of these patients consists of surgical resection and monitoring in patients not able to withstand surgery.     

Cystic tumors of the pancreas: evaluation by ultrasonography and computed tomography

The personal series of 30 cystic tumors of the pancreas [12 serous cystic tumors (SCT) and 18 mucinous cystic tumors (MCT)] is presented. All neoplasms were evaluated with ultrasonography (US) 28 of 30 with computed tomography (CT); the tumoral histotype could be correctly defined in 73% of cases (seven of 12 SCT and 15 of 18 MCT). Percutaneous fine-needle aspiration (FNA) with diagnostic aims (preparation of cytological smears and/or biochemical assays) was performed in only 10 of 30 cases, yielding a 100% sensitivity; on the whole, the combined use of imaging modalities and FNA allowed correct characterization of the cystic tumors in 27 of 30 cases (90%). The usefulness of a precise diagnostic workup of these neoplasms is emphasized, due to their prognostic and therapeutic outcome.     

Simultaneous liver mucinous cystic and intraductal papillary mucinous neoplasms of the bile duct:A case report

Cystic hepatic neoplasms are rare tumors,and are classified into two separate entities:mucinous cystic neoplasms(MCNs)and intraductal papillary mucinous neoplasms of the bile duct(IPMN-B).We report the case of a 56-year-old woman who presented with abdominal pain and jaundice due to the presence of a large hepatic multilocular cystic tumor associated with an intraductal tumor.Partial hepatectomy with resection of extrahepatic bile ducts demonstrated an intrahepatic MCN and an intraductal IPMN-B.This is the first report of the simultaneous occurrence of these two histologically distinct entities in the liver.     

Pancreas picture of the month

Summary The Magnetic Resonance Cholangio Pancreatography (MRCP) provides within a few seconds complete information on cystic degeneration of the pancreas in patients with cystic fibrosis. The authors present a case report of cystic fibrosis with a pathognomonic magnetic resonance cholangio pancreaticography image of the pancreas.     

Mucinous cystadenoma of the pancreas 17 years after excision of gallbladder because of a choledochal cyst

A 56-year-old woman who had undergone excision of the gallbladder because of a choledochal cyst had a tumorous lesion of the pancreas identified by upper abdominal ultrasonography, but an operation was not carried out, because there was no apparent increase in the cystic mass and no elevation of serum tumor markers. In October 2001, she was admitted to our hospital to check for malignancy because of elevated levels of the tumor marker Dupan-2. Abdominal enhanced computed tomography and upper abdominal ultrasonography revealed a large multilocular cystic mass in the body to tail of the pancreas. Endoscopic retrograde cholangiopancreatography showed elongation of the common duct that communicates with the common bile duct and the main pancreatic duct, indicating an anomalous arrangement of the biliary and pancreatic duct system. No apparent communications between the cystic mass and the main pancreatic duct were observed. In January 2002, the patient underwent a spleen-preserving distal pancreatectomy, and histopathological and immunohistochemical examinations led to the diagnosis of pancreatic mucinous cystadenoma with ovarian-like stroma. The mucinous cystadenoma was detected 17 years after the operation for the choledochal cyst. To the best of our knowledge, no documented case reports of mucinous cystadenoma of the pancreas associated with a choledocal cyst have been reported to date. We present here the first case report of pancreatic mucinous cystadenoma occurring in the body to tail of the pancreas, associated with a choledocal cyst.     

内镜诊治胰腺导管内乳头状粘液性肿瘤的应用

目的探讨胰腺导管内乳头状粘液性肿瘤(IPMN)的诊断、内镜下治疗,以提高对该疾病的认识及内镜对其诊断及治疗的意义。方法回顾性分析经内镜诊治的IPMN患者12例,总结并分析他们的一般情况、临床症状、影像学检查、实验室检查、内镜下治疗等方面资料。结果 12例IPMN患者以老年男性为主,无特异性临床表现,主要发生部位为胰头或钩突部,CT主要表现为囊实性低密度影,其内可有壁结节,胰管扩张伴或不伴胆管扩张,2例侵及胰腺实质。磁共振胰胆管造影(MRCP)主要表现为胰管扩张,胰腺萎缩,胰头部圆形高信号影。内镜下逆行胰胆管造影(ERCP)显示十二指肠乳头膨大,开口扩张,可见胶冻样粘液流出,胰管造影显示胰管全程扩张或胰头部囊状扩张,3例伴胆总管、肝内胆管扩张。9例行ERCP治疗,清除粘液栓并置入胰管支架,3例同时置入胆管支架。结论 IPMN是一种特殊类型的胰腺囊性疾病,影像学检查有其独特的表现,ERCP对其诊断及治疗有重要意义。     

Serous cystadenoma of the pancreas communicating with a pancreatic duct

Summary Conclusion To differentiate serous cystadenoma from other cystic lesions communicating with the pancreatic duct, careful radiological examination is necessary. Background Communication between the cystic cavity and the pancreatic duct in an ordinary serous cystadenoma is uncommon, although it is not uncommon in other cystic lesions, such as pseudocyst, mucinous cystadenoma/adenocarcinoma, and intraductal papillary tumor. Methods A serous cystadenoma of the pancreas communicating with main pancreatic duct in a 76-yr-old male is reported. Results The communication was preoperatively demonstrated by endoscopic retrograde cholangiopancreatography and confirmed by histopathological examination of the resected specimen.     

EUS in exploring the etiology of mild acute biliary pancreatitis with a negative finding of biliary origin by conventional radiological methods

Background and Aim: Conventional radiological methods, including transcutaneous ultrasonography (US), computed tomography (CT), and magnetic resonance cholangiopancreatography (MRCP) are non‐invasive and recommended for the detection of etiologies of acute biliary pancreatitis (ABP). There are still, however, a number of patients whose etiologies cannot be found by these methods. The value of endoscopic ultrasound (EUS) for this population is still unknown. The aim of the present study was to evaluate the role of EUS in exploring the unknown etiology of mild ABP. Methods: The data from patients with mild ABP admitted to Changhai Hospital, Shanghai, China, from June 2006 to December 2009 were retrospectively collected, and the results of the imaging methods in detecting biliary disorders were analyzed. Results: A total of 223 patients with mild ABP underwent both US and CT. Of these, 106 underwent additional MRCP. There were still 37 patients with unknown biliary etiologies, even after the use of the conventional methods mentioned earlier. EUS was conducted in 33 of these patients. Abnormalities associated with the etiology of mild ABP were found in 14 cases (42.4%) confirmed by subsequent endoscopic retrograde cholangiopancreatography, with biliary stones in 11 cases, biliary sludge in two cases, and ampullary adenocarcinoma in one case. Conclusion: The results suggest that EUS is helpful in the identification of the etiology of mild biliary pancreatitis when conventional radiological imaging is negative or equivocal.     

Volvulus of the gall bladder diagnosed by ultrasonography, computed tomography, coronal magnetic resonance imaging and magnetic resonance cholangio-pancreatography

A 54-year-old woman was admitted to our hospital with the complaint of right upper quadrant pain. Upon physical examination the vital signs of the patient were within normal ranges. Ultrasonography and computed tomography (CT) examination of the abdomen was obtained, which demonstrated a large dilatated cystic structure, measuring approximately 68.6 mm x 48.6 mm, with marked distension and inflammation. Additionally, the enhanced CT was characterized by the non-enhanced wall of the gallbladder. As the third examination in this study, magnetic resonance imaging (MRI), namely coronal MRI and magnetic resonance cholangio-pancreatography (MRCP), were performed. The MRCP demonstrated a dilatation of the gallbladder but detected no neck of the gallbladder. Simple cholecystectomy was performed. Macroscopic findings included a distended and gangrenous gallbladder, and closer examination revealed a counterclockwise torsion of 360 degrees on the gallbladder mesentery. Coronal MRI and MRCP showing characteristic radiography may be useful in making a definitive diagnosis.     

Multiple 'cysts' in the entire pancreas in a case of cystic adenocarcinoma of the pancreas

Abstract A case of multiple 'cysts' coexisting with cystic adenocarcinoma in the pancreas is presented. The cysts were lined by epithelium consisting of either cuboidal and flat cells or mucinous cells, which formed a papillary pattern; the former cells were more frequent and the latter were considered to be hyperplasia. The pathological findings for the diffuse multiple cysts suggested cystic disease caused by ductal stenosis, while the mucinous cells may have been related to the malignant tumour.     

胰腺肿瘤的病理诊断和鉴别诊断

胰腺肿瘤发病率近年呈上升趋势,本文仅就胰腺外分泌的上皮性肿瘤的主要类型加以介绍。其中包括胰腺导管腺癌及其主要的变型和腺泡细胞癌、胰母细胞瘤等。文中还包括了浆液性囊性肿瘤、黏液性囊性肿瘤、导管内乳头状黏液肿瘤（IPMN）和导管内乳头状嗜酸性肿瘤以及实性一假乳头状肿瘤,对上述个性肿瘤的免疫组化特点和分子特征也进行了阐述。     

Analysis of small cystic lesions of the pancreas

Summary There have been few reports on (1) the nature and pathogenesis of small cystic lesions of the pancreas, (2) their incidence, age distribution, and location, and (3) their significance as potential precursors of intraductal papillary tumors, mucinous cystic tumors, and duct cell carcinomas. Materials: Epithelial growth of small cystic lesions in 300 consecutive autopsy cases and in seven cases of small duct cell carcinoma from among 2300 elderly autopsy cases, was evaluated by histopathological analysis. One hundred eighty-six cystic lesions were found in 73 of 300 autopsy cases (24.3%). The incidence of cystic lesions increased with age. Cystic lesions were equally distributed throughout the pancreas. Epithelial atypia was histologically classified into five groups: normal epithelium; papillary hyperplasia without atypia; atypical hyperplasia; carcinomain situ; and invasive carcinoma. The incidence of each group was 47.5, 32.8, 16.4, 3.4, and 0%, respectively. Epithelia of atypical hyperplasia or carcinomain situ were more prevalent in small cystic lesions (less than 4 mm in diameter) than in larger lesions (chi-square test,p<0.05). Epithelia of dilated ductular branches adjacent to cystic lesions showed a similar degree of atypia as the epithelia of the cystic lesions themselves (p<0.01). Epithelial atypia of the main pancreatic duct was mild in all of the cases but two, and was not related to that of the cystic lesion. Among the seven cases of small duct cell carcinoma, two cases had small cancerous cystic lesions, 4.1 and 5.3 mm in diameter, within the tumor. Small cystic lesions appear to have the potential to progress to malignancy but definitive evidence has not been demonstrated. Additional studies, including molecular biological examinations, are necessary to fully understand the biology of these lesions.     

A case of triple synchronous cancers occurring in the gallbladder,common bile duct,and pancreas

We report a 74-year-old man with triple synchronous cancers occurring in the gallbladder, common bile duct, and pancreas. The patient had consulted a nearby physician because of epigastralgia and icterus. On September 30, 1997, the patient was admitted to our department for further evaluation and treatment. Abdominal computed tomography (CT) showed dilatation of the common bile duct, cystic duct, and intrahepatic bile duct, and swelling of the gallbladder. On CT, the wall of the distal common bile duct was thick and a low-density mass was detected on the left side. Cholangiography, performed via percutaneous transhepatic cholangiodrainage (PTCD), revealed stenosis of the distal common bile duct. Endoscopic retrograde pancreatography (ERP) showed marked dilatation of the main pancreatic duct. On October 17, 1997, pancreatoduodenectomy was performed under the diagnosis of carcinoma of common bile duct and pancreas. Histopathological examination revealed poorly differentiated tubular adenocarcinoma of the common bile duct, well-differentiated tubular adenocarcinoma of the gallbladder, and mucinous cystadenocarcinoma of the pancreas. These three tumors were histopathologically different. Moreover, p53-positive nuclei were recognized only in the pancreas tumor. These findings suggested that the oncogenic mechanisms of multiple synchronous cancers were not the result of only abnormal DNA reparative mechanisms. Received: March 15, 2001 / Accepted: December 14, 2001 Reprint requests to: K. Sato     

胰腺囊性病变的临床特征和诊治分析

背景:随着影像学技术的进步,胰腺囊性病变的检出率逐年升高,但鉴别不同类型的胰腺囊性病变仍是临床的棘手问题。目的:分析胰腺囊性病变的临床特征和诊治方法。方法:纳入2003年1月~2013年1月上海交通大学附属第一人民医院收治的胰腺囊性病变患者,对入组患者的临床表现、实验室检查、影像学特征以及治疗方法进行回顾性分析。结果:共49例患者纳入研究,其中假性囊肿13例、潴留囊肿4例、先天性囊肿2例、浆液性囊性肿瘤(SCN)9例、黏液性囊性肿瘤(MCN)11例、导管内乳头状黏液性肿瘤(IPMN)7例、实性-假乳头状肿瘤(SPN)3例。49例患者中16例患者无症状,其余33例患者表现为腹痛、腹胀、恶心、呕吐、发热等。13例胰腺假性囊肿患者均有急、慢性胰腺炎或外伤病史,3例IPMN患者血清CA19-9升高。B超、CT、MRI/MRCP、EUS诊断胰腺囊性病变的准确率分别为24.5%、32.7%、61.1%、100%。49例患者均接受手术治疗,分别行内引流术、囊肿切除术、胰十二指肠切除术、胰体(尾)切除术以及节段性胰腺切除术。结论:胰腺囊性病变无特异性临床表现。CT、MRI/MRCP作为无创检查手段,应广泛用于囊性病变的诊断和评估,EUS可作为进一步检查手段。选择合理的手术方案是治疗胰腺囊性病变的关键。