Cystic lesions of the pancreas. A diagnostic and management dilemma

A unique case of a typical pancreatic ductal adenocarcinoma that initially presented with a cystic component but underwent morphological changes

A 66-year-old man was initially suspected of having a microcystic serous cystic neoplasm based on magnetic resonance imaging findings of a multifocal mass measuring 46 mm in the pancreatic head, with a cystic component showing a high signal on T2-weighted images. The tumor marker levels were within normal limits. However, contrast-enhanced computed tomography revealed thick cyst walls with delayed staining, which was atypical for serous cystic neoplasms; therefore, the patient was followed up closely. Twenty-two months later, the delayed contrast area was enlarged, carbohydrate antigen 19-9 levels were elevated, and 18 F-fluorodeoxyglucose-positron emission tomography revealed increased accumulation, indicating a potentially malignant lesion. Pancreatoduodenectomy was performed and histopathological examination confirmed the diagnosis of normal-type pancreatic carcinoma with predominantly poorly differentiated cells. Based on the pathological findings and a literature review, it is highly likely that this case represents pancreatic ductal adenocarcinoma with a cystic structure from the beginning. While distinguishing pancreatic ductal adenocarcinoma from other pancreatic cystic tumors, such as serous cystic neoplasms, is critical owing to differing treatments and prognoses, caution is warranted as they may exhibit similar imaging features, as observed in our patient.

Solid pseudopapillary tumor of the pancreas: A systematic review of clinical, surgical and oncological characteristics of 1384 patients underwent pancreatic surgery

BACKGROUND

Pancreatic solid pseudopapillary tumors (SPTs) are rare clinical entity, with low malignancy and still unclear pathogenesis. They account for less than 2% of exocrine pancreatic neoplasms. This study aimed to perform a systematic review of the main clinical, surgical and oncological characteristics of pancreatic SPTs.

DATA SOURCES

MEDLINE/PubMed, Web of Science and Scopus databases were systematically searched for the main clinical, surgical and oncological characteristics of pancreatic SPTs up to April 2021, in accordance with the preferred reporting items for systematic reviews and meta-analyses (PRISMA) standards. Primary endpoints were to analyze treatments and oncological outcomes.

RESULTS

A total of 823 studies were recorded, 86 studies underwent full-text reviews and 28 met inclusion criteria. Overall, 1384 patients underwent pancreatic surgery. Mean age was 30 years and 1181 patients (85.3%) were female. The most common clinical presentation was non-specific abdominal pain (52.6% of cases). Mean overall survival was 98.1%. Mean recurrence rate was 2.8%. Mean follow-up was 4.2 years.

CONCLUSIONS

Pancreatic SPTs are rare, and predominantly affect young women with unclear pathogenesis. Radical resection is the gold standard of treatment achieving good oncological impact and a favorable prognosis in a yearly life-long follow-up.

Application of artificial intelligence in pancreas endoscopic ultrasound imaging- A systematic review

The pancreas is a vital organ in digestive system which has significant health implications. It is imperative to evaluate and identify malignant pancreatic lesions promptly in light of the high mortality rate linked to such malignancies. Endoscopic Ultrasound (EUS) is a non-invasive precise technique to detect pancreas disorders, but it is highly operator dependent. Artificial intelligence (AI), including traditional machine learning (ML) and deep learning (DL) techniques can play a pivotal role to enhancing the performance of EUS regardless of operator. AI performs a critical function in the detection, classification, and segmentation of medical images. The utilization of AI-assisted systems has improved the accuracy and productivity of pancreatic analysis, including the detection of diverse pancreatic disorders (e.g., pancreatitis, masses, and cysts) as well as landmarks and parenchyma. This systematic review examines the rapidly developing domain of AI-assisted system in EUS of the pancreas. Its objective is to present a thorough study of the present research status and developments in this area. This paper explores the significant challenges of AI-assisted system in pancreas EUS imaging, highlights the potential of AI techniques in addressing these challenges, and suggests the scope for future research in domain of AI-assisted EUS systems.

Molecular analysis with pancreaseq® in evaluation and management of pancreatic cysts: A cohort of 28 patients

Objectives

Herein, we present the PancreaSeq® results of 28 patients and emphasize the usefulness of molecular testing in evaluation of pancreatic cysts.

Material and Methods

A total of 10 (35.7%) non-diagnostic, 6 (21.4%) negative, 5 (17.8%) atypical, and 7 (25%) were positive for mucinous cystic neoplasm (MCN) pancreatic cyst aspirates were analyzed with PancreaSeq® at Mayo Clinic, Jacksonville between September 2021 and February 2023.

Results

Three non-diagnostic, two negative, three atypical, and two positive for MCN cysts were positive for KRAS and GNAS mutations. They were interpreted as intraductal papillary mucinous neoplasm (IPMN) with low risk for progression to high-grade dysplasia/adenocarcinoma. One negative case was positive for KRAS and GNAS mutation and RNF43 copy number alteration. It was interpreted as IPMN with a low risk of progression. Two non-diagnostic, one negative, and two positive for MCN cysts were positive for KRAS mutation. All were interpreted as IPMN/MCNs with low risk of progression. One positive for MCN case was positive for GNAS mutation and ALK fusion and one positive for MCN case was positive for GNAS mutation, ALK fusion, and RNF43 copy number alteration. Both were interpreted as IPMN and their risk of progression was interpreted as not well understood. One atypical case was positive for KRAS and TP53 mutation and was interpreted as IPMN/ MCNs with a high risk of progression. VHL mutation was present in one non-diagnostic case. It was interpreted as serous cystadenoma and the risk for progression was low.

Conclusion

Molecular analysis of pancreatic cysts with PancreaSeq® is useful in accurate diagnosis, especially when cytologic material is non-diagnostic and helps improve patient management.

Applications and Prospects of Artificial Intelligence-Assisted Endoscopic Ultrasound in Digestive System Diseases

Endoscopic ultrasound (EUS) has emerged as a widely utilized tool in the diagnosis of digestive diseases. In recent years, the potential of artificial intelligence (AI) in healthcare has been gradually recognized, and its superiority in the field of EUS is becoming apparent. Machine learning (ML) and deep learning (DL) are the two main AI algorithms. This paper aims to outline the applications and prospects of artificial intelligence-assisted endoscopic ultrasound (EUS-AI) in digestive diseases over the past decade. The results demonstrated that EUS-AI has shown superiority or at least equivalence to traditional methods in the diagnosis, prognosis, and quality control of subepithelial lesions, early esophageal cancer, early gastric cancer, and pancreatic diseases including pancreatic cystic lesions, autoimmune pancreatitis, and pancreatic cancer. The implementation of EUS-AI has opened up new avenues for individualized precision medicine and has introduced novel diagnostic and treatment approaches for digestive diseases.

Pancreatic Mass Characterization Using IVIM-DKI MRI and Machine Learning-Based Multi-Parametric Texture Analysis

Non-invasive characterization of pancreatic masses aids in the management of pancreatic lesions. Intravoxel incoherent motion-diffusion kurtosis imaging (IVIM-DKI) and machine learning-based texture analysis was used to differentiate pancreatic masses such as pancreatic ductal adenocarcinoma (PDAC), pancreatic neuroendocrine tumor (pNET), solid pseudopapillary epithelial neoplasm (SPEN), and mass-forming chronic pancreatitis (MFCP). A total of forty-eight biopsy-proven patients with pancreatic masses were recruited and classified into pNET (n = 13), MFCP (n = 6), SPEN (n = 4), and PDAC (n = 25) groups. All patients were scanned for IVIM-DKI sequences acquired with 14 b-values (0 to 2500 s/mm2) on a 1.5T MRI. An IVIM-DKI model with a 3D total variation (TV) penalty function was implemented to estimate the precise IVIM-DKI parametric maps. Texture analysis (TA) of the apparent diffusion coefficient (ADC) and IVIM-DKI parametric map was performed and reduced using the chi-square test. These features were fed to an artificial neural network (ANN) for characterization of pancreatic mass subtypes and validated by 5-fold cross-validation. Receiver operator characteristics (ROC) analyses were used to compute the area under curve (AUC). Perfusion fraction (f) was significantly higher (p < 0.05) in pNET than PDAC. The f showed better diagnostic performance for PDAC vs. MFCP with AUC:0.77. Both pseudo-diffusion coefficient (D*) and f for PDAC vs. pNET showed an AUC of 0.73. ADC and diffusion coefficient (D) showed good diagnostic performance for pNET vs. MFCP with AUC: 0.79 and 0.76, respectively. In the TA of PDAC vs. non-PDAC, f and combined IVIM-DKI parameters showed high accuracy ≥ 84.3% and AUC ≥ 0.84. Mean f and combined IVIM-DKI parameters estimated that the IVIM-DKI model with TV texture features has the potential to be helpful in characterizing pancreatic masses.

Giant Pseudocyst of the Pancreas: A Case Report

Pancreatic cysts are usually asymptomatic over 70% of the time. They can be benign or malignant. Enhanced imaging modalities and increased usage of routine imaging have increased the identification of pancreatic cysts. If symptomatic, abdominal pain or back pain, unexplained weight loss, jaundice, steatorrhea or palpable mass are usually the presenting complaints. Pancreatic cysts are typically assessed by cross-sectional computed tomography (CT) and magnetic resonance imaging (MRI). In this article, we present a case of a 33-year-old female with a recurrent large pancreatic pseudocyst, initially measured 15.8 cm x 14 cm x 14 cm, who was subsequently admitted to our unit and managed successfully. After undergoing diagnostic laparoscopy, exploratory laparotomy, and pancreatic cystogastrostomy, the pseudocyst shrunk to 8 cm x 6 cm over 13 weeks. It is rare to come across a pseudocyst of such large dimensions. Despite its large size, the patient presented with vague abdominal pain as the only chief complaint. The unusual presentation of symptoms and the enormous size of the pseudocyst make this a unique case. Managing giant pancreatic pseudocysts can be complex, as seen in this scenario by the multiple approaches attempted to treat the pseudocyst.

Cavernous hemangioma of an intrapancreatic accessory spleen mimicking a pancreatic tumor: A case report

BACKGROUND

Intrapancreatic accessory spleen (IPAS) is an uncommon condition, with the majority of cases presenting as solid lesions. Thus, this condition is frequently misdiagnosed as pancreatic solid neoplasm. Moreover, splenic cavernous hemangioma is a rare disorder, whereas lesions with a cystic appearance arising from IPAS have not been reported.

CASE SUMMARY

Herein, we present a case involving a 32-year-old male who had a complex cystic lesion in the tail of the pancreas revealed by conventional ultrasound. The lesion was misdiagnosed as a pancreatic cystadenoma because of its confusing anatomic location, as well as due to its peripheral nodular and internal septal enhancement patterns on contrast-enhanced ultrasound. After multidisciplinary discussion, the patient finally underwent laparoscopic pancreatic body and tail resections. Postoperative pathology demonstrated the lesion to be a cavernous hemangioma arising from the IPAS.

CONCLUSION

Cavernous hemangioma in the intrapancreatic accessory spleen may mimic pancreatic cystadenoma, which is a condition with the potential to be malignant. Imaging follow-ups or surgical interventions may be helpful for the exclusion of malignant risks in complicated cystic lesions, especially those with parietal and septal enhancements.

Automatic Pancreatic Cyst Lesion Segmentation on EUS Images Using a Deep-Learning Approach

The automatic segmentation of the pancreatic cyst lesion (PCL) is essential for the automated diagnosis of pancreatic cyst lesions on endoscopic ultrasonography (EUS) images. In this study, we proposed a deep-learning approach for PCL segmentation on EUS images. We employed the Attention U-Net model for automatic PCL segmentation. The Attention U-Net was compared with the Basic U-Net, Residual U-Net, and U-Net++ models. The Attention U-Net showed a better dice similarity coefficient (DSC) and intersection over union (IoU) scores than the other models on the internal test. Although the Basic U-Net showed a higher DSC and IoU scores on the external test than the Attention U-Net, there was no statistically significant difference. On the internal test of the cross-over study, the Attention U-Net showed the highest DSC and IoU scores. However, there was no significant difference between the Attention U-Net and Residual U-Net or between the Attention U-Net and U-Net++. On the external test of the cross-over study, all models showed no significant difference from each other. To the best of our knowledge, this is the first study implementing segmentation of PCL on EUS images using a deep-learning approach. Our experimental results show that a deep-learning approach can be applied successfully for PCL segmentation on EUS images.

Glucose Tolerance after Pancreatectomy: A Prospective Observational Follow-Up Study of Pancreaticoduodenectomy and Distal Pancreatectomy

BACKGROUND

Effects of pancreatectomy on glucose tolerance have not been clarified, and evidence regarding the difference in postoperative glucose tolerance between pancreaticoduodenectomy (PD) and distal pancreatectomy (DP) is lacking.

STUDY DESIGN

This prospective, single-center observational study analyzed 40 patients undergoing PD and 29 patients undergoing DP (Clinical trial registry number UMIN000008122). Glucose tolerance, including insulin secretion (Δ C-peptide immunoreactivity, ΔCPR) and insulin resistance (homeostasis model assessment of insulin resistance, HOMA-IR) were assessed before and 1 month after pancreatectomy using the oral glucose tolerance test (OGTT) and glucagon stimulation test. We assessed long-term hemoglobin A1c (HbA1c) levels in patients, with a follow-up time of 3 years.

RESULTS

Percentages of patients diagnosed with abnormal OGTT decreased after PD (from 12 [30%] to 7 [17.5%] of 40 patients, p = 0.096); however, they increased after DP (from 4 [13.8%] to 8 [27.6%] of 29 patients, p = 0.103), although the changes were not statistically significant. ΔCPR decreased after both PD (from 3.2 to 1.0 ng/mL, p < 0.001) and DP (from 3.3 to 1.8 ng/mL, p < 0.001). HOMA-IR decreased after PD (from 1.10 to 0.68, p < 0.001), but did not change after DP (1.10 and 1.07, p = 0.42). Median HbA1c level was higher after DP than after PD for up to 3 years, but the differences were not statistically significant.

CONCLUSIONS

In comparisons of pre- and 1 month post-pancreatectomy data, glucose tolerance showed improvement after PD, whereas it worsened after DP. Insulin secretion decreased after both PD and DP. Insulin resistance improved after PD, but did not change after DP. Further studies are warranted to clarify mechanisms of improved insulin resistance after PD.

Pancreatic mesothelial cyst

A 60-year-old woman was investigated for abdominal pain and increasing asthenia. Abdominal CT revealed a 25 mm hypodense cystic lesion in the tail of the pancreas. MRI showed a multiloculated cystic lesion, T1-hypointense and T2-hyperintense lesion, without wall enhancement. Endoscopic ultrasound detected a 25 mm multi-loculated cystic lesion, with regular margin and without pancreatic duct communication. Diagnosis of pancreatic mucinous cystadenoma was discussed and the patient was referred to surgery. She underwent distal pancreatectomy with spleen preservation. Pathological examination revealed the diagnosis of pancreatic mesothelial cyst. Histologically, the cyst was multiloculated, lined by cuboidal epithelium, ovoid nuclei and amphophilic cytoplasm, without mucin deposition or cytological atypia. Immunohistochemistry examination revealed positive staining for cytokeratin 5/6, vimentin and calretinin. At 1-year follow-up, she is in her usual health, without any symptoms.

Diagnostic approaches for pancreatic cystic lesions

BACKGROUND

Cystic lesions of the pancreas (PCLs) may be inflammatory or proliferative and making an accurate and timely pre-operative diagnosis remains a significant clinical challenge. This is principally due to the heterogeneity of the pathological processes involved. PCLs constitute an entity with diverse histology and although infrequent, the possible potential for malignant transformation of these lesions and the opportunity for curative surgery mandates that our diagnostic approaches are up to date and evidence based. In addition, improved diagnostic accuracy is crucial to prevent unnecessary surgical procedures with the inevitable associated morbidity.

METHODS

This narrative review examines the current diagnostic benchmarks and identifies novel diagnostic techniques that warrant further consideration, a number of which are beginning to be included in routine clinical practice when these PCLs are being investigated. A computerized search was made of MEDLINE, EMBASE and PubMed using the search words 'diagnostic approaches to pancreatic cystic lesions'. All relevant articles in English language or with an English abstract were retrieved and additionally cross referenced.

CONCLUSION

The increasing accuracy of available imaging techniques together with the wider availability of endoluminal ultrasound and the development of additional novel methods to assess PCLs presents an opportunity to significantly improve the pre-operative diagnosis rate. This is essential to classify the type of PCL and hence guide the management particularly with lesions where there is a likelihood of progression to more serious pathology. We have highlighted the need for a comprehensive and standardized algorithm for the diagnosis and management of PCLs.

Molecular Diagnosis of Cystic Neoplasms of the Pancreas: a Review

BACKGROUND

The prevalence of incidental pancreatic cystic neoplasms (PCNs) has increased dramatically with advancements in cross-sectional imaging. Diagnostic imaging is limited in differentiating between benign and malignant PCNs. The aim of this review is to provide an overview of biomarkers that can be used to distinguish PCNs.

METHODS

A review of the literature on molecular diagnosis of cystic neoplasms of the pancreas was performed.

RESULTS

Pancreatic cysts can be categorized into inflammatory and non-inflammatory lesions. Inflammatory cysts include pancreatic pseudocysts. Noninflammatory lesions include both mucinous and non-mucinous lesions. Mucinous lesions include intraductal papillary mucinous neoplasm (IPMN) and mucinous cystic neoplasm. Non-mucinous lesions include serous cystadenoma and solid-pseudopapillary tumor of the pancreas. Imaging, cyst aspiration, and histologic findings, as well as carcinoembryonic antigen and amylase are commonly used to distinguish between cyst types. However, molecular techniques to detect differences in genetic mutations, protein expression, glycoproteomics, and metabolomic profiling are important developments in distinguishing between cyst types.

DISCUSSION

Nomograms incorporating common clinical, laboratory, and imaging findings have been developed in a better effort to predict malignant IPMN. The incorporation of top molecular biomarker candidates to nomograms may improve the predictive ability of current models to more accurately diagnose malignant PCNs.

Progression of pancreatic cystic lesions without any risk features is associated with initial cyst size and obesity

BACKGROUND AND AIM

The clinical significance of incidental pancreatic cystic lesions (PCLs) remains unclear in those that are not accompanied by worrisome features or high-risk stigmata. We aimed to investigate the natural course of PCLs without any risk features and examine the clinical factors associated with their progression.

METHODS

We conducted a retrospective cohort study of 427 patients with PCLs, which were incidentally detected by computed tomography between January 2003 and December 2012. Progression of PCLs without any risk features and the clinical factors associated with their progression were investigated. The length of time to significant growth was also evaluated.

RESULTS

Ninety-four (22.0%) of the 427 patients had asymptomatic PCLs that showed significant growth after a median surveillance period of 5.3 years; approximately 27.7% of the patients showed significant size changes in the first 5 years, while the remaining 72.3% showed significant changes after 5 years. The cumulative rate of patients with significant growth was associated with initial cyst size and high body mass index. In the growth group, additional treatments were required for 12 patients, one of whom developed malignancy. Four patients in the stable group underwent additional treatment and showed no malignant change.

CONCLUSIONS

One-fifth of the asymptomatic PCLs significantly increased in size after a long-term follow-up period, which was associated with initial cyst size and obesity. The size of PCLs mostly increased after 5 years; although the malignancy risk of PCLs was low, it was still a concern.

Endoscopic Ultrasound-Guided Fine-Needle Aspiration Microhistology in Asymptomatic and Symptomatic Pancreatic Cystic Lesions

OBJECTIVE

This study aimed to analyze the usefulness of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) microhistology to detect malignancy in pancreatic cystic lesions (PCLs).

METHODS

Patients with PCLs were identified and submitted to EUS-FNA from January 2010 to January 2017. The percentage of samples suitable for diagnostic classification by microhistology and the positive and negative likelihood ratios to detect malignancy in asymptomatic (APC) and symptomatic (SPC) PCLs were determined.

RESULTS

Endoscopic ultrasound-guided fine-needle aspiration was performed in 510 patients. The resulting material was processed by microhistology and useful for diagnosis in 432 (84.2%). Clinical characteristics of APC (341) and SPC (169) revealed that APC patients were younger (P = 0.004) and had smaller PCLs (23 vs 35 mm; P < 0.001). In APC, we found more preneoplastic (38.7% vs 30.2%; P = 0.0016) and a lower number of malignant PCLs (8.2% vs 24.3%; P < 0.001). In APC and SPC, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of microhistology to detect malignancy were 71.4%, 99.7%, 95.2%, 97.5%, and 97.4% (k = 0.80) and 58.5%, 96.9%, 85.7%, 87.9%, and 87.6%, respectively.

CONCLUSIONS

Endoscopic ultrasound-guided fine-needle aspiration was technically feasible. Microhistology was especially useful to detect neoplastic or malignant PCLs in APC patients.

Sequential molecular and cytologic analyses provides a complementary approach to the diagnosis of pancreatic cystic lesions: a decade of clinical practice

INTRODUCTION

Many pancreatic cystic lesions (PCL) are of neoplastic nature with potential to progress to pancreatic adenocarcinoma. Early stratification of patients to either clinical observation or surgical intervention can considerably increase the survival rate. Recent studies have shown the value of molecular analysis to current diagnostic modalities.The aim of this study is to evaluate the diagnostic improvement by utilizing multiple sequential cytologic and molecular cyst fluid analyses.

MATERIALS AND METHODS

We prospectively evaluated 58 patients for whom multiple endoscopic ultrasound-guided fine-needle aspiration of cyst fluid specimens were available. Specimens were subjected to next generation sequencing to identify any recurrent gene mutations commonly found in PCL. The molecular findings were compared with cytologic and final diagnoses.

RESULTS

Cytologic diagnoses were classified into 3 groups: non-diagnostic (first visit: 33.9%, cumulative: 15.8%, P = 0.03), negative (1st visit: 53.6%, cumulative: 56.1%, P = 0.85) and atypical/suspicious/positive (first visit: 12.5%, cumulative: 28.1%, P = 0.06). The mutational analyses were clustered into indeterminate/failure (first visit: 1.7%, cumulative: 0%), KRAS/GNAS/VHL group (first visit: 50.0%, cumulative: 53.4%) and any mutation (first visit: 50.0%, cumulative: 53.4%). Mutational analysis identifies up to 72% and 71% whereas cytologic analysis classified up to 46% and 63% of lesions correctly in first and multiple visits, respectively.

CONCLUSIONS

The cytology and molecular analyses provide a complementary approach to patients with PCL. Power of molecular analysis in detection of a neoplastic lesion is significantly higher in one visit (P = 0.01) with comparable detection rates (P = 0.43) for both cytologic and molecular analyses after multiple visits.

Position of the Pancreas Division Line and Postoperative Outcomes After Distal Pancreatectomy

BACKGROUND

In distal pancreatectomy (DP), the position of the pancreas division line (PDL) changes depending on the location or nature of the tumor. Here, we investigated the relationship between PDL and postoperative complications after DP.

METHODS

We retrospectively analyzed data of 140 patients who underwent DP at Tokyo Medical and Dental University Hospital between January 2011 and September 2018. PDL was defined as the distance from the left margin of the portal vein to the edge of the pancreatic stump on the coronal plane of computed tomography.

RESULTS

The mean PDL was 15.1 (range 0-74.3) mm. PDL was significantly longer in patients with portal venous system thrombosis (PVST) than in those without PVST (47.6 vs. 0 mm, p < 0.001). The PDL_long (≥ 20 mm) group underwent surgery with a significantly shorter duration (253 vs. 294 min, p < 0.001) and experienced a lower volume of blood loss (20 vs. 256.5 mL, p < 0.001) than the PDL_short (< 20 mm) group. Six months after surgery, the increase in HbA1c level was significantly higher in the PDL_short group than in the PDL_long group (0.5 vs. 0.35%, p = 0.041). Except for PVST, there was no significant difference in postoperative complications between the two groups.

CONCLUSIONS

In DP, pancreas resection with a longer PDL resulted in a significantly shorter duration of surgery, lower estimated blood loss, and superior glucose tolerance than that with a shorter PDL.

Large cystic lymphangioma of pancreas mimicking mucinous neoplasm: case report with a review of histological differential diagnosis

Purpose

Cystic lymphangioma of the pancreas was first recognized in 1913 as a form of benign cyst. It is extremely rare, accounting for less than 1% of the lymphangiomas.

Case report

Herein, we report a case of cystic pancreatic lymphangioma diagnosed in a 51-year-old female patient who was hospitalized for a colicky upper abdominal pain for a month. Radiological imaging revealed a large multiloculated cystic pancreatic mass with enhancing septations. The patient underwent distal pancreatectomy, and the histological examination showed cystic lymphangioma.

Conclusion

Although very uncommon, cystic lymphangioma should be placed in the differential diagnosis list of pancreatic cystic lesions, at least about the multi-septated ones in asymptomatic female patients which are discovered incidentally.

110 Patients with adenosquamous carcinomas of the pancreas (PASC): imaging differentiation of small (≤ 3 cm) versus large (> 3 cm) tumors

OBJECTIVE

This study examined radiological imaging features of small (≤ 3 cm) and large (> 3 cm) adenosquamous carcinomas of the pancreas (PASC) lesions to better understand the morphology of these lesions.

METHODS

Images from 110 patients with pathologically proven PASC (80 males and 30 females, mean age: 62.6 years) were retrospectively reviewed. Two radiologists analyzed images and reached a consensus regarding the following features: location, shape, margins, presence of solid and necrotic components, rim enhancement, density/intensity during the portal venous phase, invasion of surrounding organs, vascular invasion, venous tumor thrombus formation, and enlarged lymph nodes. Differences in the imaging features between the two groups were evaluated with the Chi-square test or Fisher's exact test.

RESULTS

There were 41 small PASC lesions (mean age: 60.59 years) and 69 large PASC lesions (63.74 years). Statistical analysis demonstrated significant differences in the location, shape, adjacent organ and vessel invasion, and venous tumor thrombus formation (P < 0.05). Small PASC lesions were more frequently detected in the pancreatic head and had an ovoid shape. There was no significant difference in the presence of solid and necrotic components (P = 0.090), including approximately 3/4 of the lesions with necrosis and 1/4 purely solid lesions, enlarged lymph nodes (P = 0.068) and other features.

CONCLUSION

Regardless of the tumor size, 75% of PASC lesions present with central necrosis while 25% are purely solid. Small PASC lesions can be associated with lymph node metastasis at a relatively early stage. Large PASC lesions are likely to invade adjacent tissues and be associated with venous tumor thrombus formation.

Somatic molecular analysis augments cytologic evaluation of pancreatic cyst fluids as a diagnostic tool

Objective: Better tools are needed for early diagnosis and classification of pancreatic cystic lesions (PCL) to trigger intervention before neoplastic precursor lesions progress to adenocarcinoma. We evaluated the capacity of molecular analysis to improve the accuracy of cytologic diagnosis for PCL with an emphasis on non-diagnostic/negative specimens. Design: In a span of 7 years, at a tertiary care hospital, 318 PCL endoscopic ultrasound-guided fine needle aspirations (EUS-FNA) were evaluated by cytologic examination and molecular analysis. Mucinous PCL were identified based on a clinical algorithm and 46 surgical resections were used to verify this approach. The mutation allele frequency (MAF) of commonly altered genes (BRAF, CDKN2A, CTNNB1, GNAS, RAS, PIK3CA, PTEN, SMAD4, TP53 and VHL) was evaluated for their ability to identify and grade mucinous PCL. Results: Cytology showed a diagnostic sensitivity of 43.5% for mucinous PCL due in part to the impact of non-diagnostic (28.8%) and negative (50.5%) specimens. Incorporating an algorithmic approach or molecular analysis markedly increased the accuracy of cytologic evaluation. Detection of mucinous PCL by molecular analysis was 93.3% based on the detection of KRAS and/or GNAS gene mutations (p = 0.0001). Additional genes provided a marginal improvement in sensitivity but were associated with cyst type (e.g. VHL) and grade (e.g. SMAD4). In the surgical cohort, molecular analysis and the proposed algorithm showed comparable sensitivity (88.9% vs. 100%). Conclusions: Incorporating somatic molecular analysis in the cytologic evaluation of EUS-FNA increases diagnostic accuracy for detection, classification and grading of PCL. This approach has the potential to improve patient management.

Benign Tumors and Tumorlike Lesions of the Pancreas

The pancreas is a complex organ that may give rise to large number of neoplasms and non-neoplastic lesions. This article focuses on benign neoplasms, such as serous neoplasms, and tumorlike (pseudotumoral) lesions that may be mistaken for neoplasm not only by clinicians and radiologists, but also by pathologists. The family of pancreatic pseudotumors, by a loosely defined conception of that term, includes a variety of lesions including heterotopia, hamartoma, and lipomatous pseudohypertrophy. Autoimmune pancreatitis and paraduodenal ("groove") pancreatitis may also lead to pseudotumor formation. Knowledge of these entities will help in making an accurate diagnosis.

Changes in glucose metabolism after distal pancreatectomy: a nationwide database study

Background

This population-based study evaluated changes in glucose metabolism after distal pancreatectomy (DP).

Methods

Data from the Taiwan National Health Insurance Research Database was collected from 2001 to 2010. Of 1,980 patients who underwent DP, 507 had diabetes and 1,410 did not.

Results

Of the 1,410 non-diabetic pre-DP patients, 312 (22.1%) developed newly-diagnosed diabetes after DP. Multiple logistic regression analysis revealed that dyslipidemia [hazard ratio = 1.940; 95% confidence interval = 1.362–2.763; P < 0.001] and chronic pancreatitis (hazard ratio = 2.428; 95% confidence interval = 1.889–3.121; P < 0.001) were significantly associated with the development of diabetes after DP. On the other hand, analysis of changes in glucose metabolism among 289 pre-DP diabetes without the use of insulin revealed that 173 (59.9%) had deteriorated glucose metabolism after DP.

Conclusion

Dyslipidemia and chronic pancreatitis are risk factors for the development of diabetes. Further, more than half of the pre-DP diabetes patients without the use of insulin had deterioration of glucose metabolism after DP. Therefore, clinicians should monitor glucose metabolism and clinical symptoms of hyperglycemia among DP patients.

A new combined criterion to better predict malignant lesions in patients with pancreatic cystic neoplasms

Objective:

Cystic lesions of the pancreas have been increasingly recognized. Some lesions exhibit benign behavior, while others have unequivocal malignant potential. Thus, accurate identification of malignancy in patients diagnosed with pancreatic cystic neoplasms (PCNs) remains a major challenge. The aim of this study was to define a combined criterion to better predict malignant lesions in patients with PCNs.

Methods:

We retrospectively analyzed 165 patients who underwent resection of PCNs from October 2011 to May 2017. The relationship among malignancy and serum carbohydrate antigen 19-9 (CA19-9), preoperative neutrophil-to-lymphocyte ratio (NLR), and the presence of enhanced solid component on imaging was analyzed.

Results:

NLR before surgery in patients with malignant PCNs (2.81±2.14) was significantly higher than that in patients diagnosed with pancreatic neuroendocrine tumor (1.90±0.69, P=0.013) or healthy volunteers (1.40±0.48; P<0.001). Serum CA19-9 ≥39 U/mL, NLR >1.976 and presence of enhanced solid component were independent predictors of PCN malignancy. A combined criterion meeting any two or more of the three elements including CA19-9 ≥39 U/mL, NLR >1.976, and presence of enhanced solid component on computed tomography imaging is an indicator with a high positive predictive value of 80.5% and a high negative predictive value of 87.9%, and thus, represents a highly accurate test (86.1%).

Conclusions:

The new combined criterion is an effective predictor of tumor malignancy in patients with PCNs.

Pancreatic cancer screening: Still a delusion?

Pancreatic adenocarcinoma represents the fourth most common cause of cancer mortality and death due to pancreatic cancer (PC) have increased since 2003. Its incidence has also raised about 30% in the past decade and it is expected to become the second cause of cancer mortality by 2020 in the USA. Most PC present with metastatic disease and improvements in treatment outcomes for this group have been disappointing. These observations support the idea that screening to identify patients at an earlier stage might be an important strategy in improving overall PC outcomes. Many protocols have been tested, nevertheless, by now there is no effective screening program. Given the overall low incidence of disease and the current lack of accurate, inexpensive and noninvasive screening tests, the consensus is that widespread population-based screening for PC in the general population or in patients with only one affected first-degree relative is neither practicable nor indicated in most countries. However, a different scenario is screening patients with higher risk for PC, most of them with hereditary conditions predisposing the development of this neoplasia. In fact, some guidelines are now available helping to select these individuals at risk and to screen them, in order to achieve early detection of PC.

Serous Microcystic Adenoma of Pancreas: A Case Series from a Tertiary Care Centre in Southern India

Serous microcystic adenoma is a rare exocrine tumour of the cystic neoplasm of pancreas seen predominantly in the elderly population. The first patient was a 56-year-old diabetic woman with abdominal pain, constipation and loss of weight since two months. The second patient was a 73-year-old female with complaints of abdominal pain and back pain since one year. The third patient was a 72-year-old diabetic man with complaints of burning sensation in the right lumbar region since two months. Clinical and laboratory examinations were normal. The radiological examinations of the first two patients showed multiloculated cystic lesion in the pancreas and of the third patient was suggestive of islet cell tumour. The histopathological examination of the three patients showed multiple cysts of varying sizes lined by cuboidal epithelium, showing no atypia. All the three patients were diagnosed as serous microcystic adenoma of pancreas. On follow up, all three patients had no recurrence. Serous epithelial neoplasms need to be differentiated from their non-neoplastic counterparts and other neoplastic lesions with cystic changes, in view of the differences in management. Serous microcystic adenomas have excellent prognosis.

Endocrine Function Impairment After Distal Pancreatectomy: Incidence and Related Factors

BACKGROUND AND AIM

Little is known about the incidence of and risk factors for glucose intolerance after distal pancreatectomy. This study investigated the clinicopathologic factors associated with the development of glucose intolerance or overt diabetes mellitus (DM) after distal pancreatectomy, and the correlation between resected pancreas volume and endocrine function impairment.

METHODS

After excluding patients with preoperative DM, 101 patients who underwent distal pancreatectomy with a minimum of 1-year postoperative follow-up were enrolled in this prospective cohort. Patients were assessed preoperatively and 1 week and 12 months postoperatively by oral glucose tolerance tests and by measures of HbA1c and pancreatic volume.

RESULTS

Mean patient age was 54.1 years, mean body mass index (BMI) was 23.3 kg/m(2), and the male-to-female ratio was 1:1.8. Of the 101 patients, 21 (20.8 %) had pancreatic ductal adenocarcinoma. The median percent resected pancreas volume was 28.0 % (range 5.0-71.3 %). One year after distal pancreatectomy, 51 patients (50.5 %) had glucose intolerance, including 26 with impaired fasting glucose and 25 with DM. ROC curve analysis showed that a resected pancreas volume of 25 % showed maximum diagnostic value for development of glucose intolerance. Univariate analysis showed that female sex (58.5 vs. 36.1 %, P = 0.031), BMI (24.1 vs. 22.5 kg/m(2), P = 0.010), larger resected volume (36.5 vs. 28.0 %, P = 0.026), and lower remnant volume relative to BMI (1.7 × 10(-3) vs. 2.1 × 10(-3) m(5)/kg, P = 0.021) were risk factors for postoperative endocrine function impairment. Multivariate analysis revealed that female sex (odds ratio [OR] 5.818, P = 0.003), higher BMI (OR 10.556, P = 0.006), and resected pancreatic volume (OR 3.192, P = 0.035) were independent risk factors for endocrine impairment.

CONCLUSIONS

About 50 % of patients without preoperative DM developed impaired glucose tolerance or overt DM following distal pancreatectomy. Female sex, higher BMI, and resection of pancreatic volume >25 % were risk factors for endocrine function impairment, indicating the need for preoperative evaluation and careful perioperative glucose monitoring in these patients.

Current perspectives on pancreatic serous cystic neoplasms: Diagnosis, management and beyond

Pancreatic cystic neoplasms have been increasingly recognized recently. Comprising about 16% of all resected pancreatic cystic neoplasms, serous cystic neoplasms are uncommon benign lesions that are usually asymptomatic and found incidentally. Despite overall low risk of malignancy, these pancreatic cysts still generate anxiety, leading to intensive medical investigations with considerable financial cost to health care systems. This review discusses the general background of serous cystic neoplasms, including epidemiology and clinical characteristics, and provides an updated overview of diagnostic approaches based on clinical features, relevant imaging studies and new findings that are being discovered pertaining to diagnostic evaluation. We also concisely discuss and propose management strategies for better quality of life.

Endoscopic approach to the diagnosis of pancreatic cystic tumor

Because of the aging of the population, prevalence of medical checkups, and advances in imaging studies, the number of pancreatic cystic lesions detected has increased. Once these lesions are detected, neoplastic cysts should be differentiated from non-neoplastic cysts. Furthermore, because of the malignant potential of some neoplastic pancreatic cysts, further differentiation between benign and malignant cysts should be made regardless of their size. Although endoscopic ultrasound (EUS) has a very high diagnostic performance for pancreatic cystic lesions among the various imaging modalities, EUS findings alone are insufficient for the differentiation of pancreatic cysts and diagnosis of malignancy. In addition, cytology by EUS-guided fine-needle aspiration (FNA) has a high specificity but a low sensitivity for diagnosing malignancy in pancreatic cystic tumors. The levels of amylase, lipase, and tumor markers in pancreatic cystic fluid are considered auxiliary parameters for diagnosis of benign and malignant cysts, and a definitive diagnosis of malignancy using these parameters is difficult. Thus, in addition to EUS, cytology by EUS-FNA, and cystic fluid analysis, new techniques based on EUS-guided through-the-needle imaging, such as confocal laser endomicroscopy and cystoscopy, have been explored in recent years.

Pancreatic cystic lesions with atypical steroid response should be carefully managed in cases of autoimmune pancreatitis

BACKGROUND AND AIM

Pancreatic cysts have been reported in cases with autoimmune pancreatitis (AIP) and are often treated by corticosteroid; however, their response to steroid has not been determined fully. We aimed to see the incidence and steroid response of pancreatic cysts and the features of cysts without proper response in cases with AIP.

METHODS

Fifty-eight AIP cases were analyzed for the incidence and associated factors of pancreatic cystic lesions (≥ 10 mm). Of these, 47 cases, determined for steroid response, were retrospectively investigated for the factors associated with cyst change by corticosteroid therapy.

RESULTS

At initial diagnosis, 17 pancreatic cystic lesions were recognized in 13 cases (22.4%) of AIP, with an average size of 30 mm (range: 11-130 mm), associated with higher incidence of elevated serum amylase (38.5% vs 11.1%, P = 0.02). Of these 13 cases, nine cases with 10 cystic lesions underwent steroid therapy in our hospital. All of seven unilocular cysts were dramatically shrunken or vanished in a few months; meanwhile, three cases with multilocular cysts showed scarcely any steroid response (P = 0.008). Of these three cases, two cases were revealed to accompany pancreatic ductal carcinoma, in contrast to null of seven unilocular cysts (P = 0.07).

CONCLUSIONS

Pancreatic cystic lesions are sometimes recognized in cases with AIP, and most unilocular cysts can be minimized by corticosteroids. However, clinicians must be alert for atypical pancreatic cysts, such as multilocular cysts or cysts without obvious steroid response.

Acoustic radiation force impulse with shear wave speed quantification of pancreatic masses: A prospective study

BACKGROUND

Acoustic Radiation Force Impulse (ARFI) is a new ultrasound technique that evaluates mechanical properties of tissues. To evaluate the use of ARFI with shear waves speed quantification for pancreatic masses characterization during the ultrasound examination.

METHODS

123 pancreatic lesions were prospectively evaluated. Median shear waves speeds were compared with Mann-Whitney U test. Two reading methods were applied for the characterization of adenocarcinoma: more than one measurement above the top shear waves speed (SWS) value. Two reading methods were applied to diagnose mucinous lesion: at least 2 (method 1) or 3 (method 2) numerical measurements. Sensitivity, specificity, positive and negative predictive values and accuracy of each reading method were calculated. Forty volunteers were included for normal ARFI values.

RESULTS

In the adenocarcinoma group median SWS value was 2.74 m/s. In the volunteers group the median SWS value was 1.17 m/s. Significant difference between SWS median values of adenocarcinoma and normal pancreas was found (P < 0.05). For the diagnosis of pancreatic solid masses if more than one measurement is above the top SWS value of 4.00 m/s results in the study, the diagnosis of ductal adenocarcinoma is highly specific with specificity and PPV of 100%. Good sensitivity (73.3%) and specificity (83.3%) were obtained for the characterization of mucinous cystic lesions.

CONCLUSIONS

Acoustic Radiation Force Impulse imaging could help in the non-invasive characterization of solid and cystic lesions of the pancreas during a conventional US examination.

[Cystic lesions of the pancreas]

Due to the widespread use of computed tomography (CT) and magnetic resonance imaging (MRI) of the abdomen, the incidence of cystic pancreatic lesions as an incidental finding in asymptomatic patients is increasing; however, most of these lesions are less than 2 cm in size at the time of diagnosis making a correct classification difficult. A more differentiated understanding of the pathophysiology of these lesions has been developed during recent years. Technical improvements in imaging techniques have resulted in an increase in image resolution and has enabled radiologists to differentiate between intraductal papillary mucinous neoplasms (IPMN), serous cystic neoplasms (SCN) and mucinous cystic neoplasms (MCN). A correct classification, including the differentiation from malignant pancreatic tumors, can only be achieved by combining the knowledge of lesion pathophysiology and basic epidemiological data, such as age and sex distribution with modern imaging techniques. In conjunction with the correct diagnosis, the radiologist has to decide on the further management of the newly found lesion. This differs greatly depending on the biological behavior, especially the potential for malignant transformation, e.g. in main duct IPMN. This review gives an overview of the different cystic pancreatic lesions, their underlying pathophysiology and imaging characteristics along with recommendations for the further clinical management.

Preoperative Diagnosis of Pancreatic Cystic Lesions: The Accuracy of Endoscopic Ultrasound and Cross-Sectional Imaging

OBJECTIVE

This study aimed to evaluate the accuracy of endoscopic ultrasound (EUS) and cross-sectional imaging including multidetector computed tomography (MDCT) or magnetic resonance imaging (MRI) as a preoperative diagnostic modality for the pancreatic cystic lesions.

METHODS

Three hundred eighteen patients with surgically proven pancreatic cystic lesions were enrolled as a study cohort from 1998 to 2011. Preoperative radiological, EUS, and final histopathologic diagnosis were correlated to measure several kinds of diagnostic performance.

RESULTS

A total of 318 patients underwent preoperative MDCT, with additional imaging modalities such MRI and/or EUS in 215 (67.6%) and 108 (34.0%) patients, respectively. κ Values among the different modalities were as follows: MDCT versus pathology = 0.52 (P < 0.0001), MDCT + MRI versus pathology = 0.674 (P < 0.0001), and EUS versus pathology = 0.558 (P < 0.0001). The sensitivity and specificity in terms of ability to predict neoplastic cysts were as follows: MDCT, 83.1%/70.0%; MDCT + MRI, 94.7%/58.7%; and EUS, 88.5%/52.9%. The diagnostic accuracies of MDCT and MDCT + MRI were 61.4% (62/101) and 80.5% (173/215), respectively, and that of EUS was 70.4% (76/108).

CONCLUSIONS

Magnetic resonance imaging as an additional diagnostic modality to MDCT increased the accuracy, sensitivity, and specificity, as well in terms of predicting neoplastic cysts.

Delayed Growth in Incidental Pancreatic Cysts: Are the Current American College of Radiology Recommendations for Follow-up Appropriate?

PURPOSE

To evaluate growth kinetics of asymptomatic small (<2 cm) incidental pancreatic cysts and to assess potential implications of these in the context of current American College of Radiology recommendations.

MATERIALS AND METHODS

This institutional review board-approved HIPAA-compliant retrospective study with waiver of informed consent included patients with asymptomatic small incidental pancreatic cysts (diameter, 5-20 mm) with two or more magnetic resonance (MR) examinations performed at least 6 months apart at a tertiary institution. The largest cyst dimension was measured on T2-weighted single-shot fast spin-echo images by one of six radiologists (1-3 years of experience) who were trained to measure pancreatic cysts in a similar manner. All analysis was conducted at the patient level by choosing the cyst that exhibited the greatest growth over the follow-up period in each patient. Fisher exact, χ(2), and Kruskal-Wallis tests and analysis of variance were used to test correlation between cyst characteristics and growth.

RESULTS

A total of 259 patients (mean age, 65 years ± 11 [standard deviation], male-to-female ratio, 42:58) with 370 asymptomatic small incidental pancreatic cysts were included. At presentation, median cyst size was 9.4 mm (interquartile range [IQR], 7.0-12.2 mm), and 64 patients (25%; 95% confidence interval [CI]: 20, 30) had septations. The median imaging follow-up period was 2.2 years (IQR, 1.2-3.9 years; range, 0.5-11.0 years), with a median of three MR examinations (IQR, two to four examinations) per patient. In 171 (66%; 95% CI: 60, 72) of the 259 patients, cysts remained stable; in 18 (7%; 95% CI: 4, 11), cysts shrank; and in 70 (27%; 95% CI: 22, 33), cysts grew (median total growth and median annual growth of 4.8 mm and 2.3 mm/y, respectively). Age, cyst size, and cyst septation at presentation were not predictive of growth. Overall, 29 (11%), 16 (6%), and four (1.5%) of the cysts increased in size after 1, 2, and 3 years of initial stability, respectively. Of the 18 patients who underwent pancreatic surgery, only one patient with an intraductal papillary mucinous neoplasm had high-grade dysplasia. One patient developed pancreatic adenocarcinoma remotely at the location of the pancreatic cyst diagnosed 11 months prior.

CONCLUSION

In the majority of patients, asymptomatic small incidental pancreatic cysts remained stable during a median follow-up period of 2.2 years; however, in 27% of patients, cysts increased in size over time, with 11% growing after an initial 1-year period of stability. Current American College of Radiology recommendations to discontinue imaging follow-up after 1 year of stability may need to be reevaluated.

Diagnosis and management of cystic lesions of the pancreas

Pancreatic cystic lesions (PCLs) are being increasingly identified in recent years. They show a wide spectrum of imaging and clinical features. The diagnosis and discrimination of these lesions are very important because of the risk for concurrent or later development of malignancy. PCLs are usually first diagnosed and characterized by conventional imaging modalities such as trans-abdominal ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI). However, their ability to differentiate the benign and malignant lesions remains limited. Endoscopic US may be more helpful for the diagnosis and differentiation of PCLs because of its high resolution and better imaging characteristics than cross-sectional imaging modalities. It also allows for fine-needle aspiration (FNA) of cystic lesions for biochemical, cytological and DNA analysis that might be further helpful for diagnosis and differentiation. The management options of PCLs are to observe, endoscopic treatment or surgical resection. However, the decision for management is sometimes hampered by limitations in current diagnostic and tissue sampling techniques. As further diagnostic and non-invasive management options become available, clinical decision-making will become much easier for these lesions.

Activating mutations of GNAS and KRAS in cystic fluid can help detect intraductal papillary mucinous neoplasms of the pancreas

Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas have a risk of malignant transformation following an adenoma-carcinoma sequence. Surgical resection is often required, especially for main pancreatic duct IPMNs (MD-IPMNs). There is an urgent need for novel biomarkers to reliably differentiate IPMNs from more benign pancreatic cysts and therefore avoid unnecessary surgery. DNA sequencing has demonstrated that guanine nucleotide binding protein alpha stimulating (GNAS) activity polypeptide 1 mutations play a driving role in IPMN development. GNAS mutations have been shown to be highly specific for IPMNs, whereas oncogenic KRAS mutations have been associated with mucinous differentiation. The evaluated article by Singhi et al. helps to define the role of these mutations as biomarkers in preoperative endoscopic ultrasound fine-needle aspiration samples for detecting IPMNs. They found that the presence of a GNAS and/or a KRAS mutation was highly specific and sensitive for IPMNs.

Endoscopic ultrasound-guided therapies in pancreatic neoplasms

Endoscopic ultrasound (EUS) has evolved from being primarily a diagnostic modality into an interventional endoscopic tool for the management of both benign and malignant gastrointestinal illnesses. EUS-guided therapy has garnered particular interest as a minimally invasive approach for the treatment of pancreatic cancer, a disease often complicated by its aggressive course and poor survival. The potential advantage of an EUS-guided approach revolves around real-time imaging for targeted therapy of a difficult to reach organ. In this review, we focus on EUS-guided therapies for pancreatic neoplasms.

Incidental pancreatic cysts: role of magnetic resonance imaging

The widespread adoption of multidetector computed tomography and magnetic resonance imaging (MRI) for evaluation of intraabdominal pathology has resulted to a steady increase in the number of incidentally discovered pancreatic cysts in clinical practice during the last decades. The differential diagnosis of these cysts is broad including pseudocysts, serous cystic neoplasms, mucinous cystic neoplasms, and intraductal papillary mucinous neoplasms. The MRI has an important role both in the initial characterization of incidentally detected pancreatic cysts and the follow-up of these lesions and has become an integral part of the diagnostic algorithm for pancreatic cysts at many institutions. The inherent soft-tissue contrast of magnetic resonance cholangiopancreatography provides the vehicle for providing a specific diagnosis in many pancreatic cysts. Furthermore, an MRI-based characterization of pancreatic cysts allows for selection of those cysts that are more likely to benefit from endoscopic ultrasound and fine-needle aspiration for analysis of the fluid contents. Moreover, small asymptomatic incidental pancreatic cysts without concerning MRI features such as internal septae and/or nodularity may be safely followed with serial imaging. The lack of risk associated to repeated exposure to ionizing radiation and its ability to characterize pancreatic cysts are strong arguments for selecting MRI as the preferred imaging modality for following up these lesions. However, the recommendations for imaging follow-up continue to evolve, and several of the proposed guidelines are reviewed in this manuscript.

Is EUS-FNA of solid-pseudopapillary neoplasms of the pancreas as a preoperative procedure really necessary and free of acceptable risks?

BACKGROUND

Solid-pseudopapillary neoplasms (SPNs) of the pancreas are infrequent tumors since, as of 2014, only 2744 patients have been described. Its rarity, unclear histogenesis, pleomorphic aspect on radiology (cystic, solid or mixed) and unpredictable biological behavior with an insidious high-grade malignant potential make SPN difficult to recognize preoperatively even in its target patient population which is predominantly composed of young women (about 87% of cases).

METHODS

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) showed to improve the preoperative diagnostic yield for this tumor and obviate the risks formerly given by percutaneous biopsy.

RESULTS

In light of our experience, such a procedure could not be so innocuous as generally acknowledged.

CONCLUSION

We report the first case of rupture of pancreatic SPN following EUS-FNA and entertain both the actual and potential complications ensuing from this type of mishap.

Quality of life and functional outcome after resection of pancreatic cystic neoplasm

OBJECTIVES

The objectives of this study were to assess the long-term quality of life (QOL) after the resection of a primary pancreatic cyst and to determine predictors of outcome. Secondary outcomes were pancreatic function and survival.

METHODS

One hundred eight consecutive patients, who underwent resection between 1992 and 2007 and had nearly 60 months follow-up, were reviewed. Questionnaires and function tests were collected during scheduled outpatient clinic visits.

RESULTS

At follow-up, 20 patients had died. Five-year overall survival was 94% for benign and 62% for malignant neoplasia. Of 88 living patients, 65 (74%) returned questionnaires. Generic physical and mental QOL scores were equal or better compared with healthy references. None of the disease-specific symptom scales were above mean 50, implicating none to mild complaints. Independent predictors for good generic QOL were young age (P < 0.05) and resected malignancy (P < 0.05); predictors for good gastrointestinal QOL were male sex (P < 0.1), limited resection (P < 0.05), endocrine insufficiency (P < 0.05), and employment (P < 0.05). Endocrine insufficiency prevalence was 40%, and 59% for exocrine insufficiency.

CONCLUSIONS

After cyst resection, long-term QOL is equal to healthy references, pancreatic insufficiency is prevalent but does not impair QOL, and survival relates positive compared with solid pancreatic adenocarcinoma. The excellent long-term outcome justifies proceeding with surgery once a medical indication for resection has been established.

Molecular analysis of pancreatic acinar cell cystadenomas: Evidence of a non-neoplastic nature

The biology of pancreatic acinar cell cystadenomas has not been clearly defined. However, a non-neoplastic process, caused by a cell differentiation failure leading to a cystic transformation, has been discussed, as well as a benign neoplastic lesion. Pancreatic acinar cell cystadenomas usually consist of thin-walled unilocular or multilocular cysts, and mural nodules have been described in two cases of a recent series. In one of these nodules, chromosomal imbalances were detected, which provided preliminary evidence for a neoplastic process. The aim of the current study was to further characterize the lesions by molecular analyses. In four cases without mural nodules, the clonality was assessed by performing mutational analyses within the highly variable displacement-loop region of the mitochondrial DNA. As a result, no closer correlation was identified between different foci within the tumors than between the tumors and adjacent normal pancreatic acinar tissue, indicating polyclonality of these lesions. Further molecular analyses revealed no mutations of the β-catenin and K-ras genes. In addition, no immunohistochemical evidence was identified for mutations of Smad4 or p53. In conclusion, the results of the current study demonstrated that pancreatic acinar cell cystadenomas are non-neoplastic lesions, with the potential exception of those rare cases with mural nodules.

Mucinous Cystic Neoplasms of Pancreas

The purpose of this study was to investigate the actual management of mucinous cystic neoplasm (MCN) of the pancreas. A systematic review was performed in December 2009 by consulting PubMed MEDLINE for publications and matching the key words “pancreatic mucinous cystic neoplasm”, “pancreatic mucinous cystic tumor”, “pancreatic mucinous cystic mass”, “pancreatic cyst” and “pancreatic cystic neoplasm” to identify English language articles describing the diagnosis and treatment of the MCN of the pancreas. In total, 16,322 references ranging from January 1969 to December 2009 were analyzed and 77 articles were identified. No articles published before 1996 were selected because MCNs were not previously considered to be a completely autonomous disease. Definition, epidemiology, anatomopathological findings, clinical presentation, preoperative evaluation, treatment and prognosis were reviewed. MCNs are pancreatic mucin-producing cysts with a distinctive ovarian-type stroma localized in the body-tail of the gland and occurring in middle-aged females. The majority of MCNs are slow growing and asymptomatic. The prevalence of invasive carcinoma varies between 6% and 55%. Preoperative diagnosis depends on a combination of clinical features, tumor markers, computed tomography (CT), magnetic resonance imaging, endoscopic ultrasound with cyst fluid analysis and positron emission tomography-CT. Surgery is indicated for all MCNs.

Non-neoplastic epithelial cysts of the pancreas: a rare, benign entity

OBJECTIVES

With the increased use of cross-sectional radiologic imaging in recent years, cystic lesions of the pancreas are being diagnosed with greater frequency. While pseuodocysts have historically accounted for the majority of benign pancreatic cysts, there are a number of rare, benign cystic lesions of the pancreas that can mimic neoplastic cysts. The objective of this study was to review a single institution's experience with these benign cystic lesions of the pancreas.

METHODS

We conducted a retrospective analysis of all patients who underwent surgical resection for pancreatic disease from 2005 to 2012 at our institution. Out of a total of 947 pancreatic resections, we identified those cases performed for cystic disease, and focused upon the clinicopathologic data of patients with non-neoplastic pancreatic cysts.

RESULTS

Of the 947 pancreatic resections, 256 (27%) were performed for cystic disease. Sixteen cases (6.3%) out of the total of 256 pancreatic operations performed for cystic disease were found to have non-neoplastic cystic lesions of the pancreas. Preoperative imaging revealed primary lesions in all patients, eight of which were found incidentally. Of these lesions, 14 were suspected preoperatively to be mucinous neoplasms and two to harbor pancreatic adenocarcinoma. However, postoperative pathology revealed eight patients with ductal retention cysts, three squamoid cysts, one mucinous non-neoplastic cyst, one congenital ciliated foregut cyst, one lymphoepithelial cyst, and two endometrial cysts. Two patients had complications postoperatively, one pancreatic fistula and one SMV thrombosis. Both complications resolved with conservative management.

CONCLUSIONS

Non-neoplastic epithelial pancreatic cysts are rare, benign lesions. In our institutional experience, these lesions are often indistinguishable from cystic neoplasms of the pancreas preoperatively. As such, many of these lesions are resected unknowingly. It is important for the clinician to be well informed of the nature of these lesions, in the hopes to avoid unnecessary resection whenever possible.

Incidental pancreatic cysts: natural history and diagnostic accuracy of a limited serial pancreatic cyst MRI protocol

OBJECTIVES

To examine the natural history of incidentally detected pancreatic cysts and whether a simplified MRI protocol without gadolinium is adequate for lesion follow-up.

METHODS

Over a 10-year period, 301-patients with asymptomatic pancreatic cysts underwent follow-up (45 months ± 30). The magnetic resonance imaging (MRI) protocol included axial, coronal T2-weighted images, MR cholangiopancreatographic and fat suppressed T1-weighted sequences before and after gadolinium. Three radiologists independently reviewed the initial MRI, the follow-up studies using first only unenhanced images, then secondly gadolinium-enhanced-sequences. Lesion changes during follow-up were recorded and the added value of gadolinium-enhanced sequences was determined by classifying the lesions into risk categories.

RESULTS

Three hundred and one patients (1,174 cysts) constituted the study population. Only 35/301 patients (12 %) showed significant lesion change on follow-up. Using multivariate analysis the only independent factor of lesion growth (OR = 2.4; 95 % CI, 1.7-3.3; P < 0.001) and mural nodule development (OR = 1.9; 95 % CI, 1.1-3.4, P = 0.03) during follow-up was initial lesion size. No patient with a lesion initial size less than 2 cm developed cancer during follow-up. Intra-observer agreement with and without gadolinium enhancement ranged from 0.86 to 0.97. After consensus review of discordant cases, gadolinium-enhanced sequences demonstrated no added value.

CONCLUSION

Most incidental pancreatic cystic lesions did not demonstrate change during follow-up. The addition of gadolinium-enhanced-sequences had no added-value for risk assignment on serial follow-up.

KEY POINTS

Significant growth of pancreatic cysts occurred in a minority of patients only. No lesion <2 cm demonstrated any change during the first year of follow-up. Intra-observer agreement between MR pancreatic protocols with and without gadolinium was excellent. Gadolinium application had limited value for follow-up of asymptomatic pancreatic cystic lesions.

A review of pancreatic cyst fluid analysis in the differential diagnosis of pancreatic cyst lesions

Diagnosis and management of pancreatic cyst lesions is challenging as there is currently no investigation that offers both high diagnostic sensitivity and high specificity for the identification of potentially malignant lesions. Accurate classification of these lesions is vital in order to avoid unnecessary treatment of benign lesions and missed opportunities for early treatment of lesions that are malignant/pre-malignant. Pancreatic cyst fluid analysis has an important role in diagnosis, although all currently available investigations based on fluid analysis have significant limitations. Cytological analysis can reveal features that are specific for a certain class of cyst, but offers limited sensitivity in detecting malignant/pre-malignant cysts. Measurement of tumour markers, particularly carcinoembryonic antigen can also be informative. Concentrations of cyst fluid carcinoembryonic antigen tend to be higher in malignant/pre-malignant cysts, although there is a wide overlap between the various classes of cyst. A number of studies have suggested that diagnostic carcinoembryonic antigen cut-offs can be chosen that provide a high degree of specificity but limited sensitivity. Studies of the analytical validity of tumour marker assays in pancreatic cyst fluid analysis have highlighted discrepancies in some fluid specimens, which require further investigation. DNA analysis also has a role. In particular, K-Ras-2 mutational analysis appears to provide high specificity for detection of malignant/pre-malignant lesions. A number of diagnostic algorithms have been published, integrating use of available investigations in order to achieve the optimum discrimination of benign and potentially malignant cysts. Research into new biochemical markers and optimal use of available pancreatic cyst fluid analyses is ongoing.

European experts consensus statement on cystic tumours of the pancreas

Cystic lesions of the pancreas are increasingly recognized. While some lesions show benign behaviour (serous cystic neoplasm), others have an unequivocal malignant potential (mucinous cystic neoplasm, branch- and main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm). European expert pancreatologists provide updated recommendations: diagnostic computerized tomography and/or magnetic resonance imaging are indicated in all patients with cystic lesion of the pancreas. Endoscopic ultrasound with cyst fluid analysis may be used but there is no evidence to suggest this as a routine diagnostic method. The role of pancreatoscopy remains to be established. Resection should be considered in all symptomatic lesions, in mucinous cystic neoplasm, main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm as well as in branch duct intraductal papillary mucinous neoplasm with mural nodules, dilated main pancreatic duct >6mm and possibly if rapidly increasing in size. An oncological partial resection should be performed in main duct intraductal papillary mucinous neoplasm and in lesions with a suspicion of malignancy, otherwise organ preserving procedures may be considered. Frozen section of the transection margin in intraductal papillary mucinous neoplasm is suggested. Follow up after resection is recommended for intraductal papillary mucinous neoplasm, solid pseudo-papillary neoplasm and invasive cancer.