Endoscopic ultrasound characteristics of mucinous cystic neoplasms of the pancreas

OBJECTIVE: Mucinous cystic neoplasms of the pancreas have a more favorable prognosis than ductal adenocarcinoma. Management of a subgroup, intraductal papillary-mucinous neoplasms, is controversial. Endoscopic ultrasound (EUS) with fine-needle aspiration biopsy may emerge as the imaging modality of choice. There are few studies describing the EUS features of these tumors. METHODS: A total of 35 consecutive cases of cystic tumors of the pancreas with an established pathological diagnosis were analyzed for characteristic EUS features. RESULTS: Mucinous cystadenocarcinomas (n = 14) were more likely to be characterized by hypoechoic cystic/solid mass or complex cyst and were frequently associated with a dilated main pancreatic duct. Benign mucinous duct ectasia (n = 6) were characterized by a dilated main pancreatic duct in conjunction with hyperechoic thickening of the duct wall. The two cases of intraductal mucinous hyperplasia additionally showed a hypoechoic mass. Intraductal papillary carcinoma (n = 11) had features in common with mucinous cystadenocarcinoma but also had echogenic foci in the mass and intraductal hyperechoic lesions. The two cases of microcystic cystadenoma showed either a mixed hypoechoic solid/cystic mass or a complex cyst without the additional features seen in mucinous cystadenocarcinoma. CONCLUSIONS: EUS features seem to exist that may help to differentiate cystic neoplasms from adenocarcinoma of the pancreas and, thus, to establish the preoperative diagnosis of cystic tumors of the pancreas.     

Diagnosis of an aneurysm masquerading as a pancreatic-cyst lesion at EUS

BACKGROUND: EUS-guided FNA is commonly performed for evaluating pancreatic-cyst lesions. However, not all such lesions are true cystic neoplasms of the pancreas. OBJECTIVE: Determine the frequency at which aneurysms mimicking cysts are encountered during EUS evaluation of the pancreas. STUDY DESIGN: Observational study. SETTING: Tertiary referral center. PATIENTS: Consecutive patients found to have pancreatic cyst lesions at EUS. INTERVENTIONS: Patients with a cyst lesion in the pancreas that was suspicious for an aneurysm at EUS underwent abdominal CT imaging for a definitive diagnosis. MAIN OUTCOME MEASURES: To determine the frequency at which aneurysms are encountered during EUS while evaluating pancreatic-cyst lesions and to describe the EUS characteristics of an underlying aneurysm. RESULTS: Four of 413 lesions (0.97%, 95% confidence interval 0.26%-2.5%) that appeared as pancreatic cysts at EUS were diagnosed to be aneurysms: 2 were splenic artery aneurysms, 1 was an aneurysm of the gastroduodenal artery, and another was an infrarenal aortic aneurysm. The aneurysms had a characteristic donut-like appearance at EUS: a thick outer wall with a central anechoic area. LIMITATIONS: Observational study; small sample size. CONCLUSIONS: Aneurysms can masquerade as pancreatic-cystic lesions. Awareness of this entity is important because an inadvertent FNA during EUS may potentially lead to serious complications.     

Diagnosis of pancreatic cystic neoplasms: a report of the cooperative pancreatic cyst study

BACKGROUND & AIMS: Cysts of the pancreas display a wide spectrum of histology, including inflammatory (pseudocysts), benign (serous), premalignant (mucinous), and malignant (mucinous) lesions. Endoscopic ultrasonography (EUS) may offer a diagnostic tool through the combination of imaging and guided, fine-needle aspiration (FNA). The purpose of this investigation was to determine the most accurate test for differentiating mucinous from nonmucinous cystic lesions. METHODS: The results of EUS imaging, cyst fluid cytology, and cyst fluid tumor markers (CEA, CA 72-4, CA 125, CA 19-9, and CA 15-3) were prospectively collected and compared in a multicenter study using histology as the final diagnostic standard. RESULTS: Three hundred forty-one (341) patients underwent EUS and FNA of a pancreatic cystic lesion; 112 of these patients underwent surgical resection, providing a histologic diagnosis of the cystic lesion (68 mucinous, 7 serous, 27 inflammatory, 5 endocrine, and 5 other). Receiver operator curve analysis of the tumor markers demonstrated that cyst fluid CEA (optimal cutoff of 192 ng/mL) demonstrated the greatest area under the curve (0.79) for differentiating mucinous vs. nonmucinous cystic lesions. The accuracy of CEA (88 of 111, 79%) was significantly greater than the accuracy of EUS morphology (57 of 112, 51%) or cytology (64 of 109, 59%) (P < 0.05). There was no combination of tests that provided greater accuracy than CEA alone (P < 0.0001). CONCLUSIONS: Of tested markers, cyst fluid CEA is the most accurate test available for the diagnosis of mucinous cystic lesions of the pancreas.     

EUS diagnosis of cystic lesions of the pancreas

Summary Background. Cystic tumors of the pancreas are composed of benign, premalignant, malignant, and inflammatory lesions that are traditionally difficult to diagnose. Most of the tumors are initially detected on CT/US scanning, but often the morphological characteristics are insufficient for making a definitive diagnosis. Endoscopic ultrasound (EUS) may be an ideal tool for imaging of these lesions because it can provide highly detailed imaging without interference by bowel or air. Furthermore, EUS can direct fine needle aspiration of the lesions, providing cyst fluid for cytologic examination. The findings of cyst fluid cytology can be complemented by the use of cyst fluid tumor makers such as CEA. Using the morphologic appearance by endosonography, the results of cytology, and tumor marker analysis, EUS can often differentiate between benign, malignant, and inflammatory cystic lesions of the pancreas.     

Endoscopic ultrasound in pancreatic diseases

There are many indications for the use of endoscopic ultrasound (EUS) in the management of patients with pancreatic diseases. High-resolution imaging of the pancreas is achievable due to the close proximity between luminal structures and the pancreas. Since its introduction, EUS has had a significant impact on the diagnosis of pancreatic diseases. The detection of small lesions and neuroendocrine pancreatic tumors as well as the preoperative staging of pancreatic adenocarcinoma have been improved employing EUS. For the detection of small pancreatic tumors <2 cm in diameter, EUS appears to be the most sensitive method. EUS adds significant information to the differential diagnosis between pancreatic cancer and chronic pancreatitis, and it may be further enhanced by EUS-guided fine-needle aspiration. While the role of EUS in distinguishing between benign and malignant cystic pancreatic tumors is under discussion, EUS-guided drainage of pancreatic pseudocysts is an accepted treatment option for symptomatic individuals. One of the most important advantages of EUS apart from tumor staging is the early detection of chronic pancreatitis. EUS is as good as endoscopic retrograde cholangiopancreatography in diagnosing chronic pancreatitis in advanced stages. In early stages of the disease, when the ductal system remains normal, EUS appears to be a superior diagnostic modality because it can detect features of chronic pancreatitis in the parenchyma not visible by other techniques.     

EUS-Guided Antitumor Therapy for Pancreatic Tumors

Endoscopic ultrasound (EUS) is a very useful modality for the diagnosis and staging of pancreatic masses. With the advent of EUS-guided fine-needle aspiration technology, this modality has made a tremendous leap from imaging modality to histologic diagnosis and therapeutic intervention. EUS offers high-resolution images of and unparalleled access to the pancreas. After locating the tip of the echoendoscope in the duodenum or stomach, several drugs or local treatment modalities can be delivered directly into the pancreas. EUS-guided ethanol lavage with/without paclitaxel injection has been tested for the treatment of cystic tumors of the pancreas, with complete resolution of cystic tumor being observed in up to 70-80% of patients. Ethanol injection is also performed for the management of solid neuroendocrine tumors of the pancreas. Various type of EUS-guided injection have also been investigated for the treatment of pancreatic cancer. An activated allogenic mixed lymphocyte culture (Cytoimplant) was injected in patients with advanced pancreatic cancer. A replication-deficient adenovirus vector carrying the tumor necrosis factor-alpha gene was also delivered intratumorally by EUS. ONYX-015 is an oncolytic attenuated adenovirus that exhibits replication preferentially in malignant cells, causing cell death, and this has also been injected into pancreatic cancers under EUS guidance. EUS-guided local ablation therapies such as radiofrequency ablation, photodynamic therapy, and brachytherapy are also under investigation. EUS-guided fine-needle injection for various solid or cystic lesions is a rapidly expanding field. This article reviews the various applications of EUS for the treatment of pancreatic tumors.     

EUS in the evaluation of pancreatic cystic lesions

BACKGROUND: The differential diagnosis in pancreatic cystic lesions is often difficult despite the availability of various modern imaging modalities. This study assessed the role of EUS in the following: (1) discrimination of pseudocysts from pancreatic cystic tumors, (2) differential diagnosis between serous cystadenoma and mucinous cystic tumor, and (3) prediction of accompanying malignancy in intraductal papillary mucinous tumor. METHODS: EUS findings in 75 patients with pancreatic cystic lesions (58 cystic tumors, 17 pseudocysts) were evaluated. In the comparison of pseudocysts and cystic tumors, the latter included intraductal papillary mucinous tumor, mucinous cystic tumors, and serous cystadenomas, but not solid-pseudopapillary tumors. RESULTS: In univariate analysis, pseudocysts exhibited echogenic debris and parenchymal changes more often than cystic tumors did (respectively, 29% vs. 6%, p < 0.05; and 65% vs. 4%, p < 0.001). In contrast, septa and mural nodules were found more frequently in cystic tumors than pseudocysts (respectively, 69% vs. 12%, p < 0.001; 56% vs. 12%, p < 0.01). Multivariate analysis revealed that parenchymal changes (odds ratio [OR] = 83.59; p < 0.01); septa (OR = 30.75; p < 0.05); and mural nodules (OR = 21.38; p < 0.05) were independent predictors of differentiation between pseudocysts and cystic tumors. Serous cystadenoma exhibited diverse EUS features, as well as a honeycomb appearance. Mural nodules were found more often in mucinous cystic tumors than in serous cystadenomas (p < 0.05). There were no factors that predicted malignancy in intraductal papillary mucinous tumor. CONCLUSIONS: EUS is a useful complementary imaging method for differentiation of pancreatic cystic lesions.     

MRI对胰腺囊性肿瘤的诊断价值

目的探讨MRI对胰腺囊性肿瘤的诊断价值。方法回顾分析23例经手术病理证实的胰腺囊性肿瘤资料,总结其影像表现。结果黏液性囊性肿瘤10例,囊性肿块较大,肿块平均直径超过10 cm,由较厚的纤维壁分隔成多房囊肿,外壁光滑,边界清楚。浆液性囊腺瘤6例,病灶较小,囊内有分隔而呈放射状排列,中心瘢痕为其特征性表现。胰腺囊性转移瘤3例,均有肿瘤病史,表现不典型,需结合肿瘤病史定性。胰胚细胞瘤2例,幼儿发病,肿块巨大,肿瘤坏死囊变,形成假-假性囊肿。胰腺乳头状囊实性肿瘤1例,表现为边界清楚的囊实性肿块,囊壁上有壁结节。胰腺毛细血管瘤1例,表现与浆液性囊腺瘤相似,难以术前诊断。结论MRI对胰腺囊性肿瘤具有高度敏感性,不同病变有一定的特征性表现, 对术前定性极有价值。     

Endosonography in the diagnosis and management of pancreatic cysts

Rapid advances in radiologic technology and increased cross-sectional imaging have led to a sharp rise in incidental discoveries of pancreatic cystic lesions. These cystic lesions include non-neoplastic cysts with no risk of malignancy, neoplastic non-mucinous serous cystadenomas with little or no risk of malignancy, as well as neoplastic mucinous cysts and solid pseudopapillary neoplasms both with varying riskof malignancy. Accurate diagnosis is imperative as management is guided by symptoms and risk of malignancy. Endoscopic ultrasound(EUS) allows high resolution evaluation of cyst morphology and precise guidance for fine needle aspiration(FNA) of cyst fluid for cytological, chemical and molecular analysis. Initially, clinical evaluation and radiologic imaging, preferably with magnetic resonance imaging of the pancreas and magnetic resonance cholangiopancreatography, are performed. In asymptomatic patients where diagnosis is unclear and malignant risk is indeterminate, EUSFNA should be used to confirm the presence or absence of high-risk features, differentiate mucinous from non-mucinous lesions, and diagnose malignancy. After analyzing the cyst fluid for viscosity, cyst fluid carcinoembryonic antigen, amylase, and cyst wall cytology should be obtained. DNA analysis may add useful information in diagnosing mucinous cysts when the previous studies are indeterminate. New molecular biomarkers are being investigated to improve diagnostic capabilities and management decisions in these challenging cystic lesions. Current guidelines recommend surgical pancreatic resection as the standard of care for symptomatic cysts and those with high-risk features associated with malignancy. EUSguided cyst ablation is a promising minimally invasive, relatively low-risk alternative to both surgery and surveillance.     

Cystic tumors of the pancreas

The discovery of a cystic lesion in the pancreas implies a challenge for the physician. Approximately 10% are cystic tumors, benign to highly malignant, or true cysts, showing all stages of cellular differentiation, from benign to highly malignant tumors. Malignant cystic tumors are rare and comprise only about 1% of all pancreatic malignancies, they are potentially curable. Therefore, correct diagnosis and treatment of these lesions are of great importance. It is usually not possible to separate a pseudocyst from a benign cyst or a cystic tumor, but there are some signs and findings that could be helpful in the clinical decision. The diagnosis of a cystic pancreatic tumor requires different imaging techniques, including ultrasonography, computerized tomography, magnetic resonance imaging, and magnetic resonance cholangiopancreatography, but to distinguish a pseudocyst or a benign cyst from a potentially malignant lesion can be very difficult. The usefulness of blood tests and investigations of cyst fluid can be questionable. Today, surgical treatment of cystic pancreatic tumors can be performed with low morbidity. Therefore, we conclude that an active strategy with resection of cystic tumors of the pancreas should be recommended.     

Echoendoscopic ablative therapy for solid pancreatic tumors

Initially, endoscopic ultrasound (EUS) was developed to inspect the pancreas and other organs adjacent to the gastrointestinal tract. After introduction of curvilinear‐array echoendoscopes, EUS has been used for a variety of interventions in gastroenterology, including fine needle aspiration, pancreatobiliary drainage and tumor ablation. EUS‐guided ablation of pancreatic cystic tumors with ethanol and with or without cytotoxic agents has been studied, showing its potential to become an alternative to surgery. However, only few attempts at using ethanol ablation to treat solid pancreatic tumors have been reported. Recently, EUS‐guided radiofrequency ablation was introduced and has been cautiously applied for pancreatic cancer. This article focuses on the clinical application of EUS for the ablation of solid pancreatic tumors.     

Interobserver agreement among endosonographers for the diagnosis of neoplastic versus non-neoplastic pancreatic cystic lesions

BACKGROUND: The aim of this study was to evaluate the degree of agreement among endosonographers for EUS diagnosis of neoplastic versus non-neoplastic pancreatic cystic lesions and the specific type of cystic lesion. METHODS: Videotapes of EUS procedures from 31 consecutive cases of a range of histopathologically proven lesions, including mucinous cystic neoplasm, serous cystadenoma, neuroendocrine tumor, intraductal papillary mucinous tumor, and pseudocyst, were used to make a study videotape, which was reviewed by 8 experienced endosonographers. The reviewers, blinded to clinical and surgical histopathology results, reviewed each case for the presence or absence of the following features: abnormality of pancreatic duct and parenchyma, margins, solid component, debris, and septations. They were asked to identify each lesion as neoplastic or non-neoplastic and to give a specific diagnosis for each lesion. RESULTS: There was fair agreement between endosonographers for diagnosis of neoplastic versus non-neoplastic lesions (kappa = 0.24). Agreement for individual types of lesions was moderately good for serous cystadenomas (kappa = 0.46) but fair for the remainder. Agreement was moderately good for presence or absence of solid component (kappa = 0.43); fair for presence or absence of abnormal pancreatic duct (kappa = 0.29), debris (kappa = 0.21), and septations (kappa = 0.30); and slight for presence or absence of margins (kappa = 0.01) and abnormal pancreatic parenchyma (kappa = 0.01). Accuracy rates of EUS for the diagnosis of neoplastic versus non-neoplastic lesions ranged from 40% to 93%. CONCLUSIONS: There is little more than chance interobserver agreement among experienced endosonographers for diagnosis of neoplastic versus non-neoplastic, specific type, and EUS features of pancreatic cystic lesions.     

Endoscopic diagnosis of cystic lesions of the pancreas

Endoscopic methods are increasingly used in the diagnosis of cystic lesions of the pancreas. The two major endoscopic approaches are endoscopic ultrasonography (EUS) and transpapillary diagnosis. EUS‐guided fine‐needle aspiration cytology and EUS‐guided fine needle‐based confocal laser endomicroscopy have been used in the differential diagnosis of mucinous and non‐mucinous pancreatic cysts. EUS is the most sensitive modality for detecting mural nodules (MN) in intraductal papillary mucinous neoplasms (IPMN). Contrast‐enhanced harmonic EUS (CH‐EUS), as an add‐on to EUS, is useful for identifying and characterizing MN. Recent studies show that CH‐EUS has a sensitivity of 60–100% and a specificity of 75–92.9% for diagnosing malignant cysts. Intraductal ultrasonography and peroral pancreatoscopy are especially useful for detecting MN and IPMN. A recent meta‐analysis showed that cytological assessment of pancreatic juice using a transpapillary approach had a pooled sensitivity, specificity, and accuracy of 35.1%, 97.2%, and 92.9%, respectively, for diagnosing malignant IPMN. Further studies are warranted to determine the indications for each of these novel techniques in assessing cystic lesions of the pancreas.     

Detection and tumor staging of malignancy in cystic, intraductal, and solid tumors of the pancreas by EUS

BACKGROUND: EUS can provide detailed imaging of pancreatic malignancies and direct fine needle aspiration (FNA) of pancreatic masses. The ability of EUS to detect and stage malignancy in cystic and intraductal lesions has not been investigated. Our aim was to determine the sensitivity and specificity of EUS imaging and FNA in detecting and staging of malignancy in solid, cystic, and intraductal lesions of the pancreas. METHODS: The records of 96 patients (46 solid, 26 cystic, 24 intraductal lesions) who underwent EUS followed by surgical exploration over a 3-year period were reviewed. The accuracy of EUS for detecting and staging malignancy was calculated based on the results of surgery and histology. RESULTS: EUS-guided FNA provided evidence of malignancy in solid, cystic, and ductal lesions with sensitivities of 59.5%, 50%, and 60%, respectively. The accuracy of staging by EUS was significantly less for intraductal lesions (47%), compared with cystic (100%) and solid lesions (85%) (p < 0. 05). CONCLUSIONS: EUS can be used to detect malignancy in cystic and intraductal tumors of the pancreas.     

胰腺假性囊肿内镜超声图像的特征

目的：研究胰腺假性囊肿内镜超声图像的特征，探讨内镜超声在胰腺假性囊肿诊断中的价值。方法：对35例胰腺假性囊肿患者进行超声内镜检查。结果：在35例胰腺假性囊肿中，单发3l例，多发4例，共有囊肿41个；位于胰头13个，胰体3个，胰尾19个，胰体尾6个。囊壁光滑29例，毛糙6例；囊液透声良好19例，有絮状回声16例，囊内有分隔l例，囊壁有钙化l例，伴有胰管扩张7例；胰腺实质回声不均匀21例，胰实质钙化4例，胰腺萎缩2例，胰腺癌2例，胰腺未见异常6例。5例在胃肠道有压迹，其中1例压迫十二指肠降段致梗阻；胃底静脉曲张4例，2例引起消化道出血。结论：内镜超声可以清晰显示囊肿的大小、部位、形态以及与胰腺的关系，且能进行EUS引导下的穿刺检查，对假性囊肿的诊断和鉴别诊断均有重要意义。     

Endoscopic ultrasound guided tumor directed therapy and cyst ablation

Endoscopic ultrasonography (EUS) has become an interventional procedure for the diagnosis and treatment of various gastrointestinal and pancreatic tumors. Because of the unique anatomical location of the pancreas, EUS-guided therapies offer substantial promise for the delivery of targeted treatments. This article reviews the recent EUS-guided various therapeutic methods for pancreatic cyst and tumor ablation, especially focusing on cystic neoplasms.     

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.     

Endoluminal ultrasonography for pancreatic diseases.

Endoluminal ultrasonography was performed on 146 patients with pancreatobiliary diseases by using high-frequency, thin ultrasonic probes, and the usefulness of the new technique in diagnosis of pancreatic diseases was reported. The ultrasound probe could be inserted into the main pancreatic duct in 43 of 46 patients (93.5%), and images of the lesions could be obtained in 42 patients (91.3%). Endoluminal ultrasonography revealed a hypoechoic mass with clear margins and central echogenicity in patients with pancreatic carcinoma. Endoluminal ultrasonography showed normal pancreatic parenchyma as a fine reticular pattern and did not reveal the tumors surrounding the stenosis in patients with focal pancreatitis. Endoluminal ultrasonography in patients with intraductal papillary adenocarcinoma of the pancreas revealed cystic lesions with mural nodules more than 4 mm, mucus echoes, and solid tumors with mixed echo patterns. There were no severe complications, and acute pancreatitis occurred in none of 46 patients, but high-level serum amylase after examination occurred in 5 patients (10.9%). Endoluminal ultrasonography is useful for differential diagnosis in patients with small pancreatic tumors or cystic lesions, especially intraductal papillary tumors of the pancreas. Endoluminal ultrasonography is recommended as a precise examination for the diagnosis of cystic lesions of the pancreas or stenosis of the main pancreatic duct after ERCP and EUS.     

Macrocystic type of serous cystadenoma with a communication between the cyst and pancreatic duct

A 42-year-old woman with a cystic lesion in the head of the pancreas was evaluated by using abdominal ultrasonography, a computed tomographic scan, magnetic resonance imaging and endoscopic retrograde pancreatography. Multiple cystic lesions, 5 cm in diameter, which had papillary protrusion inside the cyst in the head of the pancreas and had the communication between the cysts and pancreatic duct, were determined. Pylorus-preserving pancreaticoduodenectomy was performed under the diagnosis of mucinous cystic neoplasm of the pancreas. Although the cut surface of the tumor showed a macrocystic tumor of 3 cm in diameter, part of the cyst wall was cavernous. A histopathological examination showed single-layered cuboidal cells, which lead to the diagnosis as being serous cystadenoma of the pancreas. Serous cystadenoma is a rare, almost benign pancreatic tumor. The macrocystic subtype of serous cystadenoma is even more rare. We describe a patient who had this macrocystic subtype of serous cystadenoma with a communication between the cyst and pancreatic duct. This case illustrates the difficulty in the diagnosis of cystic lesions in the pancreas, and might support the single category of cystic lesions of the pancreas.