Diagnostic imaging of cystic pancreatic neoplasms

Pancreatic serous cystic neoplasm mimicking intraductal papillary mucinous neoplasm: Two case reports and literature review

RATIONALE

Serous cystic neoplasms (SCNs) are treated as benign lesions. It is widely known that SCN rarely have a connection with the main pancreatic duct (MPD), which helps differentiate them from other cystic lesions, such as intraductal papillary mucinous neoplasm (IPMN). However, very rare cases where the SCN appears connected to the MPD cause diagnostic confusion.

PATIENT CONCERNS

We present 2 patients with SCN (1 male, 54, and 1 female, 42). Both patients were asymptomatic, without abnormal laboratory results.

DIAGNOSIS

In both cases, abdominopelvic computed tomography and pancreatic magnetic resonance imaging scans revealed a multilobulated cystic lesion in communication with the MPD. Since the size of each patient's lesion was >3 cm and there was connectivity with the MPD, it was strongly suspected to be a branch duct-type IPMN with worrisome features rather than SCN and surgical intervention was considered.

INTERVENTIONS

Both neoplasms were misdiagnosed as IPMN due to appearing connected with the MPD on radiologic imaging. Surgery was performed.

OUTCOMES

A final diagnosis of microcystic serous cystadenoma of the pancreas without connectivity of MPD was confirmed in both patients.

LESSONS

An unnecessary surgery was performed due to atypical radiologic features in which the pancreatic duct seems to be connected to the pancreatic cystic lesion on magnetic resonance imaging, leading to misdiagnosis of SCN as IPMN. Particular attention should be paid to interpretation of clinicoradiologic findings of pancreatic cystic lesions, especially to the decision of surgical intervention. Also, awareness of presence of the atypical radiologic features of SCN may broaden the knowledge base of radiologists.

LESSONS

An unnecessary surgery was performed due to atypical radiologic features in which the pancreatic duct seems to be connected to the pancreatic cystic lesion on magnetic resonance imaging, leading to misdiagnosis of SCN as IPMN. Particular attention should be paid to interpretation of clinicoradiologic findings of pancreatic cystic lesions, especially to the decision of surgical intervention. Also, awareness of presence of the atypical radiologic features of SCN may broaden the knowledge base of radiologists.

Deep Learning-Based Differentiation between Mucinous Cystic Neoplasm and Serous Cystic Neoplasm in the Pancreas Using Endoscopic Ultrasonography

Mucinous cystic neoplasms (MCN) and serous cystic neoplasms (SCN) account for a large portion of solitary pancreatic cystic neoplasms (PCN). In this study we implemented a convolutional neural network (CNN) model using ResNet50 to differentiate between MCN and SCN. The training data were collected retrospectively from 59 MCN and 49 SCN patients from two different hospitals. Data augmentation was used to enhance the size and quality of training datasets. Fine-tuning training approaches were utilized by adopting the pre-trained model from transfer learning while training selected layers. Testing of the network was conducted by varying the endoscopic ultrasonography (EUS) image sizes and positions to evaluate the network performance for differentiation. The proposed network model achieved up to 82.75% accuracy and a 0.88 (95% CI: 0.817–0.930) area under curve (AUC) score. The performance of the implemented deep learning networks in decision-making using only EUS images is comparable to that of traditional manual decision-making using EUS images along with supporting clinical information. Gradient-weighted class activation mapping (Grad-CAM) confirmed that the network model learned the features from the cyst region accurately. This study proves the feasibility of diagnosing MCN and SCN using a deep learning network model. Further improvement using more datasets is needed.

The Role of Positron Emission Tomography in Clinical Management of Intraductal Papillary Mucinous Neoplasms of the Pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas represent a heterogeneous group of tumors, increasingly diagnosed in clinical practice. An early differential diagnosis between malignant and benign lesions is crucial to patient management and the choice of surgery or observation. The therapeutic approach is currently based on a patient’s clinical, biochemical, and morphological characteristics. The latest published International Consensus Guidelines (ICG) make no mention of the role of metabolic assessments of IPMNs. The aim of this study was to review the current literature, examining the role of 18-fluorodeoxyglucose (FDG) positron emission tomography (PET) in IPMN management. An extensive literature review was conducted according to the 2009 Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and 10 articles were analyzed in detail, focusing on the value of PET as opposed to other standard imaging criteria. Data were retrieved on 419 patients. The 18-FDG-PET proved more sensitive, specific, and accurate than the ICG criteria in detecting malignant IPMNs (reaching 80%, 95%, and 87% vs. 67%, 58%, and 63%, respectively). Metabolic assessments may be used as an additional tool for the appropriate management of patients with doubtful imaging findings.

New criteria to differentiate between mucinous cystic neoplasm and serous cystic neoplasm in pancreas by endoscopic ultrasound: A preliminarily confirmed outcome of 41 patients

Background and Objectives:

The ability to distinguish between mucinous cystic neoplasm (MCN) and serous cystic neoplasm (SCN) in the pancreas preoperatively by endoscopic ultrasound (EUS) remains a clinical challenge. To address this problem, we have developed new criteria using EUS findings and cyst fluid carcinoembryonic antigen (CEA) in the clinic. In this study, the validity and reliability of these criteria were assessed.

Materials and Methods:

Between April of 2015 and May of 2016, a total of 59 patients with pancreatic cystic neoplasms underwent EUS and ultimately received surgery in our hospital. Of the 59 patients, 21 were pathologically verified to have MCN while 20 were verified to have SCN in the pancreas. For these 41 patients with MCN or SCN, EUS findings and cyst fluid CEA were reviewed.

Results:

For the 41 patients reviewed, the new criteria were found to identify MCN with 85.71% sensitivity (95% confidence interval [CI], 64%–97%), 80.00% specificity (CI, 56%-94%), and 82.93% accuracy (CI, 68%–93%).

Conclusion:

These new criteria were preliminarily found to produce excellent results, with 82.93% accuracy determined for the differential diagnosis between MCN and SCN by EUS. However, a further prospective study with a larger population must be carried out to fully assess these new criteria.

Prospective validation of microRNA signatures for detecting pancreatic malignant transformation in endoscopic-ultrasound guided fine-needle aspiration biopsies

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease. Novel biomarkers are required to aid treatment decisions and improve patient outcomes. MicroRNAs (miRNAs) are potentially ideal diagnostic biomarkers, as they are stable molecules, and tumour and tissue specific.

RESULTS

Logistic regression analysis revealed an endoscopic-ultrasound fine-needle aspiration (EUS-FNA) 2-miRNA classifier (miR-21 + miR-155) capable of distinguishing benign from malignant pancreatic lesions with a sensitivity of 81.5% and a specificity of 85.7% (AUC 0.930). Validation FNA cohorts confirmed both miRNAs were overexpressed in malignant disease, while circulating miRNAs performed poorly.

METHODS

Fifty-five patients with a suspicious pancreatic lesion on cross-sectional imaging were evaluated by EUS-FNA. At echo-endoscopy, the first part of the FNA was sent for cytological assessment and the second part was used for total RNA extraction. Candidate miRNAs were selected after careful review of the literature and expression was quantified by qRT-PCR. Validation was performed on an independent cohort of EUS-FNAs, as well as formalin-fixed paraffin embedded (FFPE) and plasma samples.

CONCLUSIONS

We provide further evidence for using miRNAs as diagnostic biomarkers for pancreatic malignancy. We demonstrate the feasibility of using fresh EUS-FNAs to establish miRNA-based signatures unique to pancreatic malignant transformation and the potential to enhance risk stratification and selection for surgery.

Differentiation of branch duct intraductal papillary mucinous neoplasms from serous cystadenomas of the pancreas using contrast-enhanced sonography

OBJECTIVES

The purpose of this study was to determine whether contrast-enhanced sonography can improve the ability to differentiate branch duct intraductal mucinous neoplasms from serous cystadenomas of the pancreas compared to conventional (unenhanced) sonography alone.

METHODS

Between March 2008 and May 2012, there were 20 patients with branch duct intraductal mucinous neoplasms and 25 with serous cystadenomas in our institute, for whom preoperative conventional and contrast-enhanced sonographic results were available. The final diagnosis was obtained by histopathology. Various conventional and contrast-enhanced sonographic characteristics were retrospectively evaluated by 2 radiologists in consensus. A receiver operating characteristic curve analysis was used to evaluate the diagnostic value of conventional and contrast-enhanced sonography for discriminating between the two entities.

RESULTS

Three conventional sonographic characteristics (microcysts, cysts with internal echoes, and main pancreatic duct dilatation) and 2 contrast-enhanced sonographic characteristics (communication between the lesion and main pancreatic duct and enhancement of mural nodules) significantly improved the ability to differentiate branch duct intraductal mucinous neoplasms from serous cystadenomas. The area under the receiver operating characteristic curve increased from 0.691 with conventional sonography to 0.859 with combined contrast-enhanced and conventional ultrasonography (P = .043).

CONCLUSIONS

In this series of patients, the addition of contrast-enhanced sonography to conventional sonography improved the ability to differentiate branch duct intraductal mucinous neoplasms from serous cystadenomas.

Pancreatic cysts: etiology, diagnosis and management

Pancreatic cysts involve a wide spectrum of pathologies from post-inflammatory cysts to malignant neoplasms. Pancreatic pseudocysts, serous cystadenomas, mucinous cystadenomas, intraductal papillary mucinous neoplasms (IPMNs) and solid pseudopapillary tumors occur most frequently. Differential diagnosis involves the following imaging investigations: transabdominal ultrasonography (TUS), contrast enhanced ultrasonography (CEUS) and endoscopic ultrasonography (EUS), computed tomography (CT), magnetic resonance (MR) and magnetic resonance cholangiopancretography (MRCP), endoscopic retrograde cholangiopancretography (ERCP). The cyst fluid cytology is performed in difficult differential diagnosis between pseudocysts and benign and potentially malignant or malignant tumors. Most frequently, viscosity, amylase, CEA and CA 19-9 levels are determined. Imaging findings should be correlated with cytology. The management depends on the cyst type and size. Small asymptomatic pseudocysts, serous cystadenomas and branchduct IPMNs should be carefully observed, whereas symptomatic large or uncertain serous cystadenomas and cystadenocarcinomas, mucinous cystadenomas and cystadenocarcinomas, main-duct IPMNs and large branch-duct IPMNs with malignant features, serous and mucinous cystadenocarcinomas, and solid pseudopapillary tumors require surgery. Pseudocysts are usually drained. Percutaneous / EUS-guided or surgical cyst drainage can be performed. Complicated and uncertain pseudocysts and cystic tumors need surgical resection. The type of surgery depends on cyst location and size and includes proximal, central, distal, total pancreatectomies and enucleation.

Imaging of indeterminate pancreatic cystic lesions: a systematic review

BACKGROUND

Pancreatic cystic lesions are an increasing problem and investigation of these cysts can be fraught with difficulty. There is currently no gold standard for diagnosis or surveillance. This review was undertaken to determine the present reliability of the characterisation, assessment of malignant potential and diagnosis of pancreatic cystic lesions using available imaging modalities.

METHODS

A Medline search using the terms 'pancreatic', 'pancreas', 'cyst', 'cystic', 'lesions', 'imaging', 'PET'. 'CT', 'MRI' and 'EUS' was performed. Publications were screened to include studies examining the performance of CT, MRI, MRCP, EUS and 18-FDG PET in the determination of benign or malignant cysts, cyst morphology and specific diagnoses.

RESULTS

Nineteen studies were identified that met the inclusion criteria. 18-FDG PET had a sensitivity and specificity of 57.0-94.0% and 65.0-97.0% and an accuracy of 94% in determining benign versus malignant cysts. CT had a sensitivity and specificity of 36.3-71.4% and 63.9-100% in determining benign disease but had an accuracy of making a specific diagnosis of 39.0-44.7%. MRI had a sensitivity and specificity of 91.4-100.0% and 89.7% in assessing main pancreatic duct communication.

CONCLUSION

CT is a good quality initial investigation to be used in conjunction with clinical data. MRCP can add useful information regarding MPD communication but should be used judiciously. PET may have a role in equivocal cases to determine malignancy. Further examination of CT-PET in this patient group is warranted.

A new case of solitary true pancreatic cyst

A true cyst of the pancreas is extremely rare, and few cases have been reported in adult patients. The authors report a new case of this rare pathological entity. A 35-year-old male patient was admitted to our unit with a cystic mass, about 6cm in diameter, located in the pancreatic head, in proximity to the duodenum, vena cava, biliary tree and right kidney. Clinical features and imagery were suggestive for a benign neoplasm, as did surgical findings. Cystoduodenostomy was done. Histological finding revealed a cyst lined by cuboidal epithelium without morphologic alterations. Analysis of the cyst fluid showed a high level of CA 19-9 (10,000Uml(-1)). After 1-year follow-up, the patient was found to be doing well without any abdominal symptoms. Ultrasound images revealed no cyst recurrence.

Pancreatic mucinous cystadenoma in an adult with cystic fibrosis

Cystic fibrosis (CF) is the most frequent genetic disease in the Caucasian population. It seems to be associated with an increased risk of digestive cancer but only few cases of pancreatic tumors have been reported. As pancreatic lesions of the pancreas in CF patients are not rare, their etiological diagnosis is substantial. We report herein a case of a mucinous cystadenoma in a patient with CF. Diagnosis and management of pancreatic cystic tumors in patients at high risk of operative morbidity are challenging. When the potential malignancy of a pancreatic cystic mass cannot be well established in a CF patient, partly because of frequent chronic pancreatitis lesions, we suggest that surgical management should be undertaken instead of radiological surveillance.

Elevated microRNA miR-21 levels in pancreatic cyst fluid are predictive of mucinous precursor lesions of ductal adenocarcinoma

BACKGROUND

Biomarkers for the diagnostic classification of pancreatic cysts are urgently needed. Deregulated microRNA (miRNAs) expression is widespread in pancreatic cancer. We assessed whether aberrant miRNAs in pancreatic cyst fluid could be used as potential biomarkers for cystic precursor lesions of pancreatic cancer.

METHODS

Cyst fluid specimens were prospectively collected from 40 surgically resected pancreatic cysts, and small RNAs were extracted. The 'mucinous' cohort included 14 intraductal papillary mucinous neoplasms (including 3 with an associated adenocarcinoma) and 10 mucinous cystic neoplasms; the 'nonmucinous' cohort included 11 serous cystadenomas and 5 other benign cysts. Quantitative reverse transcription PCR was performed for five miRNAs (miR-21, miR-155, miR-221, miR-17-3p, miR-191), which were previously reported as overexpressed in pancreatic adenocarcinomas.

RESULTS

Significantly higher expression of miR-21, miR-221, and miR-17-3p was observed in the mucinous versus nonmucinous cysts (p < 0.01), with the mean relative fold differences being 7.0-, 7.9-, and 5.4-fold, respectively. Receiver operating characteristic curves demonstrated the highest median area under the curve for miR-21, with a median specificity of 76%, at a sensitivity of 80%.

CONCLUSION

This pilot study demonstrates that profiling miRNAs in pancreatic cyst fluid samples is feasible and can yield potential biomarkers for the classification of cystic lesions of the pancreas. and IAP.

The management of the pancreatic cystic neoplasm: the role of the EUS in Japan

Diagnosis of cystic lesions of the pancreas is made by clinical history taking, physical examination, blood biochemical tests and diagnostic imaging, such as transabdominal ultrasound, endoscopic ultrasound (EUS), cross-sectional imaging (computed tomography and/or magnetic resonance imaging) and endoscopic retrograde cholangiopancreatography, bearing in mind the known characteristic features of the various cystic lesions that can occur in this organ. Among others, EUS, endowed with a sharp local resolving power, has been described as a highly useful examination method, because it enables concurrent fine-needle aspiration (FNA). EUS has an important role in the differential diagnosis and tumor grading (benign, premalignant or malignant) of cystic lesions. Although the differential diagnosis of cystic lesions of the pancreas based on EUS morphology is practicable to some extent, there have also been reports showing that the diagnosis might vary with the endosonographer and that the diagnostic performance of this method for tumor grading is not necessarily high. In countries overseas, differential diagnosis and tumor grading of cystic lesions of the pancreas are actively undertaken not merely by EUS morphology, but also by cyst-fluid EUS-guided FNA (EUS-FNA) cytology and measurements of pancreatic enzymes and tumor markers, and importance is attached to EUS-FNA in the latest version of the American Society for Gastrointestinal Endoscopy Guideline and in the diagnostic strategies for cystic diseases of the pancreas. Meanwhile, the current Japanese consensus is that EUS-FNA is not recommended in cases of mucinous cystic lesions suspected as being intraductal papillary mucinous neoplasm or mucinous cystic neoplasm.

Pancreatic serous cystadenoma with compression of the main pancreatic duct: an unusual entity

Serous cystadenoma is a common benign neoplasm that can be managed without surgery in asymptomatic patients provided that the diagnosis is certain. We describe a patient, whose pancreatic cyst exhibited a radiological appearance distinct from that of typical serous cystadenoma, resulting in diagnostic difficulties. CT and MRI showed a 10 cm-polycystic tumor with upstream dilatation of the main pancreatic duct (MPD), suggestive of intraductal papillary mucinous tumor (IPMT). Ultrasonographic aspect and EUS-guided fine-needle aspiration gave arguments for serous cystadenoma. ERCP showed a communication between cysts and the dilated MPD, compatible with IPMT. The patient underwent left pancreatectomy with splenectomy. Pathological examination concluded in a serous cystadenoma, with only a ductal obstruction causing proximal dilatation.

Endoscopic ultrasound in the assessment of solid and cystic pancreatic lesions

Pancreatic masses can be solid or cystic, benign or malignant. Rapid and accurate diagnosis is essential for optimal management. Clinical presentation and radiological appearance are often inadequate for a definitive diagnosis. Endoscopic ultrasound allows more detailed assessment of the pancreas than traditional imaging techniques.

Cystic neoplasms of the pancreas

Cystic neoplasms of the pancreas are a heterogeneous group of pancreatic tumors that vary in pathophysiology, malignant potential, clinical course, and outcomes. Their management is heavily predicated on establishing an accurate diagnosis. This can be particularly challenging, but can often be achieved by a thorough history and physical examination combined with high-quality, thin-slice computed tomography, although additional diagnostic tools may be required. Once the diagnosis is established, treatment can range from simple observation to total pancreatectomy. This decision rests on a clear and complete understanding of each disease process in the context of the patient's age and comorbidities. This article reviews the most common cystic neoplasms of the pancreas, focusing on their diagnosis and management.

Variability in measurements of pancreatic cyst size among EUS, CT, and magnetic resonance imaging modalities

BACKGROUND

Cyst size is an important factor in the management of pancreatic cysts, both in predicting the need for surgery and the frequency of follow-up.

OBJECTIVE

To determine agreement and precision of EUS, CT, and magnetic resonance imaging (MRI) modalities in the evaluation of pancreatic cyst diameter.

DESIGN

Retrospective chart review.

SETTING

Tertiary-care center, January 2000 to June 2009.

PATIENTS

This study involved 175 patients presenting for EUS evaluation of pancreatic cysts, with size measured by at least two of the aforementioned imaging studies within a 90-day period.

MAIN OUTCOME MEASUREMENTS

Largest cyst diameter from EUS, CT, MRI/MRCP, and surgical pathology.

RESULTS

A total of 175 patients underwent EUS. Seventy-three had CT plus EUS, 33 had MRI/MRCP plus EUS, 23 had MRI/MRCP plus CT, and 15 had all imaging studies, occurring within 90 days of each other. Median size differences between studies: EUS and CT (ie, absolute value of size determined by EUS minus size determined by CT) = 4 mm (range 0-25 mm), EUS and MRI = 4 mm (range 0-17 mm), CT and MRI = 3 mm (range 2-20 mm). Median size differences for surgical pathology specimens compared with results of 12 EUS, 13 CT, and 8 MRI/MRCP studies were as follows: EUS and pathology = 9.5 mm (range 0-20 mm), CT and pathology = 5 mm (range 0-21 mm), MRI and pathology = 5.5 mm (range 2-44 mm).

LIMITATIONS

Interobserver variability and small sample of surgical pathology cysts.

CONCLUSION

There is considerable variation in size estimates of pancreatic cysts by different imaging modalities, which practitioners should take into account when making management decisions. Use of a single imaging modality is recommended during follow-up. The precision of imaging studies for measuring pancreatic cysts must be prospectively defined if change in size is to be reliably used for clinical management.

Diagnosis of pancreatic tumors by endoscopic ultrasonography

Pancreatic tumors are highly diverse, as they can be solid or cystic, and benign or malignant. Since their imaging features overlap considerably, it is often difficult to characterize these tumors. In addition, small pancreatic tumors, especially those less than 2 cm in diameter, are difficult to detect and diagnose. For characterizing pancreatic tumors and detecting small pancreatic tumors, endoscopic ultrasonography (EUS) is the most sensitive of the imaging procedures currently available. This technique also provides good results in terms of the preoperative staging of pancreatic tumors. EUS-guided fine needle aspiration (EUS-FNA) has also proved to be a safe and useful method for tissue sampling of pancreatic tumors. Despite these advantages, however, it is still difficult to differentiate between benign and malignant, solid or cystic pancreatic tumors, malignant neoplasms, and chronic pancreatitis using EUS, even when EUS-FNA is performed. Recently, contrast-enhanced EUS with Doppler mode (CE-EUS) employing ultrasound contrast agents, which indicate vascularization in pancreatic lesions, has been found to be useful in the differential diagnosis of pancreatic tumors, especially small pancreatic tumors. However, Doppler ultrasonography with contrast-enhancement has several limitations, including blooming artifacts, poor spatial resolution, and low sensitivity to slow flow. Consequently, an echoendoscope was developed recently that has a broad-band transducer and an imaging mode that was designed specifically for contrast-enhanced harmonic EUS (CEH-EUS) with a second-generation ultrasound contrast agent. The CEH-EUS technique is expected to improve the differential diagnosis of pancreatic disease in the future. This review describes the EUS appearances of common solid and cystic pancreatic masses, the diagnostic accuracy of EUS-FNA, and the relative efficacies and advantages of CE-EUS and CEH-EUS along with their relative advantages and their complementary roles in clinical practice.

Typical and atypical manifestations of serous cystadenoma of the pancreas: imaging findings with pathologic correlation

OBJECTIVE

The purpose of this article is to present the typical and atypical manifestations of serous cystadenoma, which can be visualized with cross-sectional imaging.

CONCLUSION

Serous cystadenomas of the pancreas have various distinguishing imaging features. Typically, a serous cystadenoma is morphologically classified as having either a polycystic, honeycomb, or oligocystic pattern. Atypical manifestations of serous cystadenoma can include giant tumors with ductal dilatation, intratumoral hemorrhages, solid variants, unilocular cystic tumors, interval growth, and a disseminated form.

[Importance of endoscopy and endosonography for chronic pancreatitis and benign pancreas tumors]

Endoscopic retrograde pancreatography (ERP) and endoscopic ultrasound (EUS) are superior to cross-sectional imaging procedures for detection of low-grade pancreatitis, but detection of duct alterations is more reliable by middle and high-grade chronic pancreatitis than by low-grade. In addition to assessment of alterations in the pancreatic duct, EUS also allows detection of parenchymatous alterations. Because of the risk of post-ERP pancreatitis, ERP has been mostly eliminated from diagnostic procedures. In contrast, endoscopic retrograde cholangiopancreatography (ERCP) allows an unrivalled access to interventional treatment of inflammatory alterations of the biliopancreatic duct system, by retrograde, non-penetrable papillae even in the rendezvous procedure with EUS-assisted probing of the Ductus Wirsungianus. Despite the technical success of endoscopic procedures, surgical duct decompression has proven to be superior for relief from pancreatitic pain. Biliary drainage is also more likely to be successful on a permanent basis using surgical procedures than by repeat multi-stenting, at least by calcifying pancreatitis. Peroral transgastral transmural therapy of postpancreatitic necroses opens up further options over surgical removal of necroses.

Diagnosis and management strategy for cystic neoplasm of the pancreas

OBJECTIVE

This article aimed to propose a management strategy for cystic neoplasm of the pancreas based on the available evidence in the medical literature.

METHODS

A Medline search was undertaken to identify articles from 1988 to 2008 using the keywords 'pancreatic cyst', 'pancreatic neoplasms', and 'cystic neoplasm of pancreas'. Additional papers were identified by a manual search of the references from the key articles.

COMMENTS

The optimal management of cystic neoplasms of pancreas remains controversial and should be individualized based on the balance between the risk and benefit. Multiple factors such as patient's comorbidity, performance status, life expectancy, and surgical risk, should be weighed against the malignant potential of the cyst.

Laparoscopic and Hand-Assisted Distal Pancreatectomy

With the increased use of CT, discovering incidental pancreatic lesions has become commonplace. Lesions in the distal pancreas lend themselves well to laparoscopic resection. We reviewed our experience with laparoscopic distal pancreatectomy. During the study period, 32 distal pancreatectomies were performed. There were 20 females. Mean patient age was 58.0 years (range, 23–83 years) and mean body mass index was 29.9 kg/m2 (range, 19.9–44.7 kg/m2). Technique was laparoscopic (25) or hand-assisted (seven) with one conversion in each group. The spleen was preserved in six patients (18.8%). Mean operative time overall was 238 minutes (range, 140–515 minutes); hand-assisted was 222 minutes and laparoscopic was 254 minutes. Estimated blood loss averaged 221 mL (range, 50–1800 mL). Mean tumor size was 2.7 cm (range, 0.6–7 cm). Tumor pathology was serous cystadenoma (10), neuroendocrine tumor (six), mucinous cystic neoplasm (four), intrapapillary mucinous neoplasm (four), adenocarcinoma (three), other (four), and solid pseudopapillary neoplasm (one). Mean length of stay was 5 days (range, 3–11 days). Complications were pancreatic fistula (six), wound infection (two), pulmonary embolism (one), pancreatitis (one), myocardial infarction (one), postoperative bleed from combined laparoscopic bilateral oophorectomy (one), and pancreatic stump staple line bleed requiring reoperation (one). There were no perioperative deaths. All pancreatic fistulas resolved with conservative management.

Differentiation of intraductal papillary mucinous neoplasms from other pancreatic cystic masses: comparison of multirow-detector CT and MR imaging using ROC analysis

PURPOSE

To compare the diagnostic performance of multirow-detector computed tomography (MDCT) and magnetic resonance imaging (MRI) in the differentiation of intraductal papillary mucinous neoplasms (IPMNs) from other pancreatic cystic masses.

MATERIALS AND METHODS

A total of 53 patients with pathologically proven pancreatic cystic lesions who had undergone MDCT and MRI were included in this study. Two radiologists analyzed the morphologic features of the lesions and graded the lesion conspicuity on each examination. The readers assigned their confidence level regarding the differentiation of IPMN from other lesions and predicting ductal communication of the lesion. The radiologists' diagnostic confidence was compared using receiver operating characteristic (ROC) analysis.

RESULTS

The Az values for each observer for predicting ductal communication of the lesion and differentiating IPMN from other lesions were as follows: For MRI they were respectively 0.949 and 0.995 for reader 1, and 0.916 and 0.932 for reader 2. For MDCT they were respectively 0.790 and 0.875 for reader 1, and 0.774 and 0.850 for reader 2. In addition, for differentiating IPMNs from other lesions, MRI was significantly more accurate than MDCT (P < 0.05) for one observer, but for the other observer there was no significant difference between the two examinations (P = 0.059). For predicting ductal communication of the cystic lesions for both observers, MRI was significantly more accurate than MDCT (P < 0.05). The weighted kappa values indicate good agreement (kappa = 0.61) between observers for MDCT, and excellent agreement (kappa = 0.82) for MRI.

CONCLUSION

Pancreatic MRI shows better diagnostic performance than MDCT for differentiating IPMNs from other cystic lesions of the pancreas.

Presentation and management of pancreatic cystic neoplasms

Pancreatic cystic neoplasms are less frequent than other pancreatic tumors, but because of the wide availability and improvement of modern imaging methods, these neoplasms are being recognized with increasing frequency and it is often possible to be differentiated preoperatively not only from other cystic pancreatic disorders but also from one another. Most patients have no symptoms while clinical signs are not really useful in the clinical work up, and when they are present, they never help us to identify the type of pathology. Treatment differs with the diagnosis. Serous cystic neoplasms are uniformly benign and usually do not mandate resection unless this lesion is symptomatic. In contrast, mucinous cystic neoplasms and intraductal papillary mucinous neoplasms have a premalignant or malignant tendency, and therefore should be managed aggressively by pancreatic resection; in the absence of invasive disease, prognosis is excellent after appropriate surgery, but the presence of invasive malignancy signifies a poor prognosis. Solid pseudopapillary neoplasms have nonaggressive behavior and their management is related to the extension of the disease. The purpose of this article is to review the types of pancreatic cystic neoplasms, their diagnosis, indications for surgical treatment, and outcome.

The clinicopathologic features of intraductal papillary mucinous neoplasms of the pancreas

Since first described in 1982, intraductal papillary mucinous neoplasm (IPMN) has been the preferred term to describe the proliferation of the pancreatic ductal epithelium. It is totally different from pancreatic carcinoma in epidemiology, histology, pathology and prognosis. According to the site of involvement, IPMNs are classified into three categories, i.e. main duct type, branch duct type, and combined type. Most branch duct IPMNs are benign, whereas the other two types are often malignant. A large branch duct IPMN and marked dilation of the main pancreatic duct indicate the presence of adenoma at least. The additional existence of large mural nodules increases the possibility of malignancy in all types. The prognosis is more favorable after complete resection of benign and non-invasive malignant IPMNs. Malignant IPMNs that become more aggressive after parenchymal invasion necessitate adequate lymph node dissection. On the other hand, asymptomatic branch duct IPMNs without mural nodules can be observed without the need for resection for a considerable period of time. Our review addresses available data, current understanding, controversy, and future directions about IPMNs.

Mimicks of pancreatic malignancy in patients with chronic pancreatitis: correlation of computed tomography imaging features with histopathologic findings

Differentiation of chronic pancreatitis and pancreatic carcinoma can be a clinical and radiologic dilemma. Several patients with chronic pancreatitis can undergo unnecessary major abdominal surgery for benign lesions. This pictorial review illustrates the computed tomographic findings and histopathologic features of lesions mimicking pancreatic neoplasm in patients with chronic pancreatitis. Several benign lesions can simulate pancreatic malignancy in patients with chronic pancreatitis. Knowledge of the computed tomographic appearance of these benign entities is important to prevent unnecessary surgeries.

Intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND/AIMS

Intraductal papillary mucinous neoplasms (IPMNs) are neoplasms of the pancreatic duct epithelium characterized by intraductal papillary growth and thick mucin secretion. Quantities of mucin fill the main and/or branches of pancreatic ducts and cause ductal dilatation. This review encompasses IPMNs, including symptoms, diagnosis, management, and prognosis.

METHODS

A Pubmed database search was performed. All abstracts were reviewed and all articles in which cases of IPMNs could be identified were further scrutinized. Further references were extracted by cross-referencing.

RESULTS

Only one-third of all patients are symptomatic. According to the site of involvement, IPMNs are classified into three types: main duct type, branch duct type, and combined type. Most branch type IPMNs are benign, while the other two types are frequently malignant. The presence of large mural nodules increases the possibility of malignancy in all types. Presence of a large branch type IPMN and marked dilatation of the main duct indicate the existence of adenoma at least. Synchronous or metachronous malignancies may be developed in various organs. Endoscopic retrograde cholangiopancreatography, endoscopic ultrasonography, and intraductal ultrasonography clearly demonstrate ductal dilatation and mural nodules, while magnetic resonance pancreatography best visualizes the entire outline of IPMNs.

CONCLUSIONS

Prognosis is excellent after complete resection of benign and non-invasive malignant IPMNs. The extent of pancreatic resection and the intraoperative management of resection margins remain controversial. Total pancreatectomy should be reserved for patients with resectable but extensive IPMNs involving the whole pancreas; its benefits, however, must be balanced against operative and postoperative risks. Regular monitoring for disease recurrence is important after surgery.

[Solid-pseudopapillary tumor of pancreas]

Solid-pseudopapillary tumor of pancreas is a very rare neoplasm of low malignant potential and unknown origin. It generally occurs in young women and the prognosis is usually good after complete surgical removal. Two cases of solid pseudopapillary tumor with distinct disease duration are reported.

Cystic neoplasms of the pancreas; What a clinician should know

Primary cystic neoplasms of the pancreas (serous cystic neoplasms, mucinous serous neoplasms, and intraductal papillary mucinous neoplasms) are lesions of emerging importance. With the wide availability of modern imaging methods, these neoplasms are being recognized with increasing frequency. Due to the improvement of these sophisticated imaging techniques, it is often possible to differentiate preoperatively these primary pancreatic cystic neoplasms not only from other cystic pancreatic disorders (such as pancreatic pseudocysts) but also from one another. This differentiation is very important for the clinician, since these neoplasms have radically different biologic behavior. Serous cystic neoplasms are uniformly benign and usually do not mandate resection unless the lesion is symptomatic. In contrast, mucinous cystic neoplasms and intraductal papillary mucinous neoplasms have a premalignant or overtly malignant tendency, and therefore should be managed aggressively by pancreatic resection. In these mucinous cystic neoplasms, recognition of an underlying malignancy is often not possible without a detailed histopathologic examination of the entire resected specimen. In the absence of invasive disease, prognosis is excellent after appropriate surgery. The presence of invasive malignancy signifies a poor prognosis.

Intraductal papillary mucinous neoplasms of the pancreas

BACKGROUND

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas is a new pathological entity. It is diagnosed with increasing frequency. However, its natural history and management are still not well defined.

METHODS

A Medline search was undertaken to identify articles using the keywords "intraductal papillary mucinous neoplasms of pancreas", "pancreatic neoplasms", and "pancreatic cyst". Additional papers were identified by a manual search of the references from the key articles.

RESULTS

Surgical resection is the only treatment which can produce a cure. The reported overall 5-year survival for IPMN after surgical resection varies from 36% to 77%; for non-invasive IPMN, 77% to 100% and for invasive IPMN, 27% to 60%. The overall recurrence rate was 7% to 43%. IPMN can recur either as disseminated disease or as isolated pancreatic remnant recurrence even after surgical resection with negative margins.

CONCLUSIONS

Based on the available evidence, patients with IPMN should undergo complete surgical resection. The extent of pancreatic resection and the intra-operative management of resection margins remain controversial. Balancing the risk of recurrence and the morbidity of total pancreatectomy, routine total pancreatectomy for IPMN is not recommended. Total pancreatectomy should only be reserved for patients with resectable but extensive IPMN which involves the whole pancreas. Regular monitoring for disease recurrence is important after surgery as there is a risk of recurrence in both non-invasive and invasive IPMN, and repeat resection for an isolated recurrence in the pancreatic remnant gives good results.

Approach to cystic pancreatic lesions

Cystic neoplasms of the pancreas represent the best example of a malignant precursor in the pancreas. There are many parallels between pancreatic cystic neoplasms and the colon polyp-cancer sequence. In the past, cystic neoplasms of the pancreas were thought to be relatively rare, composing less than 10% of cancers of the pancreas. With the greater use of cross-sectional imaging, an increasing number of these neoplasms are being seen.