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

Radiomics advances in the evaluation of pancreatic cystic neoplasms

With the development of medical imaging, the detection rate of pancreatic cystic neoplasms (PCNs) has increased greatly. Serous cystic neoplasm, solid pseudopapillary neoplasm, intraductal papillary mucinous neoplasm and mucinous cystic neoplasm are the main subtypes of PCN, and their treatment options vary greatly due to the different biological behaviours of the tumours. Different from conventional qualitative imaging evaluation, radiomics is a promising noninvasive approach for the diagnosis, classification, and risk stratification of diseases involving high-throughput extraction of medical image features. We present a review of radiomics in the diagnosis of serous cystic neoplasm and mucinous cystic neoplasm, risk classification of intraductal papillary mucinous neoplasm and prediction of solid pseudopapillary neoplasm invasiveness compared to conventional imaging diagnosis. Radiomics is a promising tool in the field of medical imaging, providing a noninvasive, high-performance model for preoperative diagnosis and risk stratification of PCNs and improving prospects regarding management of these diseases. Further studies are warranted to investigate MRI image radiomics in connection with PCNs to improve the diagnosis and treatment strategies in the management of PCN patients.

Early Detection of Pancreatic Cancer: Role of Biomarkers in Pancreatic Fluid Samples

Pancreatic ductal adenocarcinoma (PDAC) is the fourth leading cause of cancer-related deaths worldwide. Most patients with PDAC present with symptomatic, surgically unresectable disease. Therefore, the establishment of strategies for the early detection is urgently needed. Molecular biomarkers might be useful in various phases of a strategy to identify high-risk individuals in the general population and to detect high-risk lesions during intense surveillance programs combined with imaging modalities. However, the low sensitivity and specificity of biomarkers currently available for PDAC, such as carbohydrate 19-9 (CA19-9), contribute to the late diagnosis of this deadly disease. Although almost all classes of biomarker assays have been studied, most of them are used in the context of symptomatic diseases. Compared to other body fluids, pancreatic juice and duodenal fluid are better sources of DNA, RNA, proteins, and exosomes derived from neoplastic cells and have the potential to increase the sensitivity/specificity of these biomarkers. The number of studies using duodenal fluid with or without secretin stimulation for DNA/protein marker tests have been increasing because of the less-invasiveness in comparison to pancreatic juice collection by endoscopic retrograde cholangiopancreatography (ERCP) and endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Genomic analyses have been very well-studied, and based on PDAC progression model, mutations detected in pancreatic juice/duodenal fluid seem to indicate the presence of microscopic precursors and high-grade dysplasia/invasive cancer. In addition to known proteins overexpressed both in precursors and PDACs, such as CEA and S100P, comprehensive proteomic analysis of pancreatic juice from patients with PDAC identified many proteins which were not previously described. A novel technique to isolate exosomes from pancreatic juice was recently invented and identification of exosomal microRNA’s 21 and 155 could be biomarkers for diagnosis of PDAC. Since many studies have explored biomarkers in fluid samples containing pancreatic juice and reported excellent diagnostic accuracy, we need to discuss how these biomarker assays can be validated and utilized in the strategy of early detection of PDAC.

Needle tract seeding and abscess associated with pancreatic fistula after endoscopic ultrasound-guided fine-needle aspiration

We present the first report of needle tract seeding with simultaneous abscess associated with pancreatic fistula occurring after endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) for pancreatic ductal adenocarcinoma (PDA). A 72-year-old woman complained of fever 18 days after EUS-FNA for PDA of the pancreatic tail with a retention cyst. An abscess associated with pancreatic fistula containing necrotic debris formed in the EUS-FNA needle tract was successfully treated with endoscopic drainage and antibiotics. Distal pancreatectomy with partial gastrectomy was performed after neoadjuvant chemotherapy. Complete resection was achieved but peritoneal lavage cytology was positive for cancer. Pathology of the resected specimen revealed cancer cells invading the gastric submucosa at the EUS-FNA puncture site from the serosal side. The lining of the retention cyst was free of cancer cells. Liver metastases and peritoneal carcinomatosis were seen 3 months after surgery. While needle tract seeding has recently received attention as a complication of EUS-FNA, endoscopists should also be alerted to the possibility of abscess associated with pancreatic fistula after EUS-FNA for PDA.

Utility of endoscopic ultrasound and endoscopic ultrasound-guided fine-needle aspiration for the diagnosis and management of pancreatic cystic lesions: Differences between the guidelines

Recent advances and frequent use of cross-sectional imaging studies have increased opportunities for incidental diagnoses of pancreatic cystic lesions (PCL). In the management of PCL, distinguishing between mucinous versus non-mucinous and malignant versus benign cysts is important to diagnose pancreatic cancer in its early stage. For this reason, there have been several guidelines to manage PCL. Endoscopic ultrasound (EUS) and EUS-guided fine-needle aspiration (FNA) play important roles in the guidelines, although there are some differences in their roles. In this review, we aimed to evaluate the current status of EUS and EUS-FNA in the management of PCL and the status of these procedures in the guidelines.

Quality assessment of the guidelines on cystic neoplasms of the pancreas

BACKGROUND

Though cystic pancreatic neoplasms (CPNs) are being increasingly detected, their evaluation and management are still debated and have lead to publication of multiple guidelines for diagnostic work-up, indications for resection, and non-operative management with follow-up strategies of CPNs.

AIMS

To analyze available guidelines in order to evaluate their overall quality and clinical applicability, indications for surgical resection and its extent, modalities and timing of follow-up when non-operative management is indicated.

METHODS

After a systematic search of the English literature, we selected eight guidelines for assessment according to the Appraisal of Guidelines, Research and Evaluation in Europe (AGREE) II instrument.

RESULTS

One guideline received the lower AGREE score regarding the "scope and purpose", "rigor of development" and "clarity and presentation" domains, whereas one received the best score for "stakeholder involvement" domain. No differences were found among different guidelines regarding the "applicability". The overall quality assessment score showed that only two guidelines were significantly lower than the others. According to the practical utilization recommendation score, four guidelines were considered as having full applicability in clinical practice.

CONCLUSION

Existing guidelines provide adequate guidance, at least with the present knowledge, for the management of cystic pancreatic lesions; however, not any one was satisfactory to all aspects related to the management of CPN. An update of the existing guidelines should be considered if and when more evidence-based data are available.

Rare nonneoplastic cysts of pancreas

Pancreatic cysts represent a small proportion of pancreatic diseases, but their incidence has been recently increasing. Most pancreatic cysts are identified incidentally, causing a dilemma for both clinicians and patients. In contrast to ductal adenocarcinoma, neoplastic pancreatic cysts may be cured by resection. In general, pancreatic cysts are classified as neoplastic or non-neoplastic cysts. The predominant types of neoplastic cysts include intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, serous cystic neoplasms, and solid pseudopapillary neoplasms. With the exception of serous type, neoplastic cysts, have malignant potential, and in most cases requires resection. Non-neoplastic cysts include pseudocyst, retention cyst, benign epithelial cysts, lymphoepithelial cysts, squamous lined cysts (dermoid cyst and epidermal cyst in intrapancreatic accessory spleen), mucinous nonneoplastic cysts, and lymphangiomas. The incidence of nonneoplastic, noninflammatory cysts is about 6.3% of all pancreatic cysts. Despite the use of high-resolution imaging technologies and cytologic tissue acquisition with endosonography, distinguishing nonneoplastic from neoplastic cysts remains difficult with most differentiations made postoperatively. Nonetheless, the definitive distinction between non-neoplastic and neoplastic cysts is crucial as unnecessary surgery could be avoided with proper diagnosis. Therefore, consideration of these rare disease entities should be entertained before deciding on surgery.

Confocal laser endomicroscopy in gastrointestinal and pancreatobiliary diseases

Confocal laser endomicroscopy (CLE) is an emerging diagnostic procedure that enables in vivo pathological evaluation during ongoing endoscopy. There are two types of CLE: endoscope-based CLE (eCLE), which is integrated in the tip of the endoscope, and probe-based CLE (pCLE), which goes through the accessory channel of the endoscope. Clinical data of CLE have been reported mainly in gastrointestinal (GI) diseases including Barrett's esophagus, gastric neoplasms, and colon polyps, but, recently, a smaller pCLE, which goes through a catheter or a fine-needle aspiration needle, was developed and clinical data in the diagnosis of biliary stricture or pancreatic cysts have been increasingly reported. The future application of this novel technique expands beyond the pathological diagnosis to functional or molecular imaging. Despite these promising data, the generalizability of the procedure should be confirmed especially in Japan and other Asian countries, where the current diagnostic yield for GI luminal diseases is high. Given the high cost of CLE devices, cost-benefit analysis should also be considered.

Large pancreatic mucinous cystic neoplasm during pregnancy: what should be done?

Pancreatic mucinous cystic neoplasms are uncommon and their occurrence in pregnancy is extremely rare. The authors report the unique case of a newborn weighing 3,620 g, delivered vaginally with no complications by a patient with a large 'silent' pancreatic mucinous cystic neoplasms, and analyze the very few other reports. With no available protocol, this case highlights an interesting dilemma on the management of pregnancy and delivery as well on the timing of pancreatic surgery. Despite its limitations, MRI remains the most accurate investigation either for differentiating the mucinous from nonmucinous cysts or for evaluating the malignancy, but echography is also very useful. Without symptoms, all low-grade malignant potential tumors, independent of the moment of their diagnosis during pregnancy, should be resected 2-3 months after delivery and we believe that the best option is a term vaginal birth, even in the presence of a large cyst and large fetus. On the contrary, all high-grade malignant potential tumors, discovered in the first two trimesters of pregnancy should be resected during the second trimester, and followed by a vaginal delivery at term. If high-grade malignant potential tumor is diagnosed in the third trimester, an early vaginal delivery followed by surgery is recommended. Finally, the patient's preference is crucial.

The incidental cystic pancreas mass: a practical approach

Technical advances in cross-sectional imaging have led to the discovery of incidental cystic pancreatic lesions in the oncology and non-oncology population that in the past remained undetected. These lesions have created a diagnostic and management dilemma for both clinicians and radiologists: should these lesions be ignored, watched, aspirated, or removed? In this review, recommendations concerning the assessment of the more common pancreatic cystic incidental lesions are presented.