Background: The WHO classified pancreatic neuroendocrine neoplasms (pNEN) in 2010 as G1, G2, and neuroendocrine carcinoma (NEC), according to Ki67 labeling index (LI). However, the clinical behavior of NEC is still not fully studied. We aimed to clarify the clinicopathological and molecular characteristics of NECs. Methods: We retrospectively evaluated the clinicopathological characteristics, KRAS mutation status, treatment response, and the overall survival of eleven pNEC patients diagnosed between 2001 and 2014 according to the WHO 2010. We subclassified WHO-NECs into well-differentiated (WDNEC) and poorlydifferentiated NEC (PDNEC), the latter further subdivided into large and small cell type. Results: The median Ki67 LI was 69.1% (range, 40% - 95%) and the median tumor size was 35 mm. 11 WHO-NECs were subclassified 4 WDNEC and 7 PDNEC, and further separated PDNEC into 3 large cell and 4 small cell subtypes. Comparisons of WDNEC vs. PDNEC revealed hypervascularity on CT, 50% (2/4) vs. 0% (0/7) (P = 0.109); median Ki67 LI, 46.3% (40% - 53%) vs. 85% (54% - 95%) (P = 0.001); KRAS mutations, 0% (0/4) vs. 85.7% (6/7) (P = 0.015); response rates to platinum-based chemotherapy, 0% (0/2) vs.100% (4/4) (P = 0.067) and median survival, 227 vs. 186 days (P = 0.227). Conclusions: The WHO-NEC category may be composed of heterogeneous disease entities, namely WDNEC and PDNEC. These subgroups tended to exhibit differing Ki67 and KRAS mutation profiles, and distinct response to chemotherapy. Further studies for the re-evaluation of the current WHO 2010 classification is warranted.

Background: The WHO classified pancreatic neuroendocrine neoplasms (pNEN)in 2010 as G1, G2, and neuroendocrine carcinoma (NEC), according to Ki67labeling index (LI). However, the clinical behavior of NEC is still not fully studied.We aimed to clarify the clinicopathological and molecular characteristics ofNECs.Methods: We retrospectively evaluated the clinicopathological characteristics,KRAS mutation status, treatment response, and the overall survival of elevenpNEC patients diagnosed between 2001 and 2014 according to the WHO 2010.We subclassified WHO-NECs into well-differentiated (WDNEC) and poorlydifferentiatedNEC (PDNEC), the latter further subdivided into large and smallcell type.Results: The median Ki67 LI was 69.1% (range, 40% - 95%) and the mediantumor size was 35 mm. 11 WHO-NECs were subclassified 4 WDNEC and 7PDNEC, and further separated PDNEC into 3 large cell and 4 small cell subtypes.Comparisons of WDNEC vs. PDNEC revealed hypervascularity on CT, 50% (2/4)vs. 0% (0/7) (P = 0.109); median Ki67 LI, 46.3% (40% - 53%) vs. 85% (54% -95%) (P = 0.001); KRAS mutations, 0% (0/4) vs. 85.7% (6/7) (P = 0.015); responserates to platinum-based chemotherapy, 0% (0/2) vs.100% (4/4) (P = 0.067) andmedian survival, 227 vs. 186 days (P = 0.227).Conclusions: The WHO-NEC category may be composed of heterogeneousdisease entities, namely WDNEC and PDNEC. These subgroups tended to exhibitdiffering Ki67 and KRAS mutation profiles, and distinct response to chemotherapy.Further studies for the re-evaluation of the current WHO 2010 classification iswarranted.

BACKGROUND: Both endoscopic ultrasound-guided celiac plexus neurolysis (EUS-CPN) and tumor ablation using ethanol are very common procedures, and the utility of these therapies has already been reported in prominent journals. However, their effectiveness appears temporary and insufficient, especially EUS-CPN. We therefore have to consider new reagents for improving the results. The present study examined the best concentration of ethanol and povidone iodine mixed with atelocollagen for more effective therapies. METHODS: The effects of the new reagents were confirmed in three live pigs. At first, we injected three kinds of reagents (including indigo carmine) in three separate areas of para-aortic tissue under EUS guidance in one pig. At more than 4 hours after injection, we checked ethanol injection sites after dissection. In next study, we performed EUS-guided injection of a total of six kinds of reagents (two kinds of ethanol, three kinds of povidone iodine, and control atelocollagen) into the livers of two living pigs. After 2 weeks, we examined tissue damage to the liver in the two pigs. RESULTS: The 75% ethanol (absolute ethanol 3.75 mL + 1% atelocollagen 1.25 mL + a very small amount of indigo carmine) was seen like blue gel, and still remained in the para-aortic tissue. Brownish areas of povidone iodine mixed with 3% atelocollagen exhibited clear, regular borders with greatly reduced infiltration into surrounding tissue compared to others. CONCLUSION: We concluded that 75% ethanol mixed with 1% atelocollagen appears optimal for EUS-CPN. Povidone iodine mixed with 3% atelocollagen may be suitable for small tumor ablation therapy.
Celiac Plexus* ; Endoscopic Ultrasound-Guided Fine Needle Aspiration ; Endosonography ; Ethanol ; Indicators and Reagents ; Indigo Carmine ; Liver ; Povidone-Iodine ; Swine

Endoscopic ultrasonography (EUS) combines endoscopy and intraluminal ultrasonography, and allows imaging with a high-frequency transducer over a short distance to generate high-resolution ultrasonographic images. EUS is now a widely accepted modality for diagnosing pancreatobiliary diseases. EUS-guided fine-needle aspiration (EUS-FNA) using a curved linear-array echoendoscope was initially described more than 20 years ago, and since then many researchers have expanded its indications to sample diverse lesions and have also used it for various therapeutic purposes. EUS-guided biliary drainage (EUS-BD) is one of the therapeutic procedures that has been developed using a curved linear-array echoendoscope. Technically, EUS-BD includes rendezvous techniques via transesophageal, transgastric, and transduodenal routes, EUS-guided choledochoduodenostomy (EUS-CDS), and EUS-guided hepaticogastrostomy (EUS-HGS). Published data have demonstrated a high success rate, albeit with a comparatively high rate of nonfatal complications for EUS-CDS and EUS-HGS, and a comparatively low success rate with a low complication rate for the rendezvous technique. At present, these procedures represent an alternative to surgery or percutaneous transhepatic biliary drainage (PTBD) for patients with obstructive jaundice when endoscopic biliary drainage (EBD) has failed. However, these procedures should be performed in centers with extensive experience in linear EUS and therapeutic biliary ERCP. Large prospective studies are needed in the near future to establish standardized EUS-BD procedures as well as to perform controlled comparative trials between EUS-BD and PTBD, between rendezvous techniques and direct-access techniques (EUS-CDS and EUS-HGS), and between EBD and EUS-BD.
Biopsy, Fine-Needle ; Cholangiopancreatography, Endoscopic Retrograde ; Choledochostomy ; Dioxolanes ; Drainage ; Endoscopy ; Endosonography ; Fluorocarbons ; Humans ; Jaundice, Obstructive ; Transducers

SUMMARY OF EVENT: Pneumoderma, mediastinal emphysema, and bilateral pneumothorax were developed in the patient who had undergone transesophageal endoscopic ultrasonography-guided rendezvous technique. Chest drainage was performed immediately. TEACHING POINT: Transesophageal approach carries the potential risks of severe complications such as mediastinal emphysema, mediastinitis, and pneumothorax. To prevent puncturing through the esophagus, clipping the esophagogastric junction using a forward-viewing scope before procedure is very useful. In cases of inadvertent transesophageal puncture, devices other than the needle should not be passed through the site.
Drainage* ; Endosonography ; Esophagogastric Junction ; Esophagus ; Humans ; Mediastinal Emphysema ; Mediastinitis ; Needles ; Pneumothorax ; Punctures ; Thorax

Background/Aims: The Japan Gastroenterological Endoscopy Society (JGES) has published guidelines for gastroenterological endoscopy in patients undergoing antithrombotic treatment. These guidelines classify endoscopic ultrasound-guided biliary drainage (EUS-BD) as a high-risk procedure. Nevertheless, the bleeding risk of EUS-BD in patients undergoing antithrombotic therapy is uncertain. Therefore, this study aimed to assess the bleeding risk in patients undergoing antithrombotic therapy. Methods: This single-center retrospective study included 220 consecutive patients who underwent EUS-BD between January 2013 and December 2018. We managed the withdrawal and continuation of antithrombotic agents according to the JGES guidelines. We compared the bleeding event rates among patients who received and those who did not receive antithrombotic agents. Results: A total of 18 patients (8.1%) received antithrombotic agents and 202 patients (91.8%) did not. Three patients experienced bleeding events, with an overall bleeding event rate of 1.3% (3/220): one patient was in the antithrombotic group (5.5%) and two patients were in the non-antithrombotic group (0.9%) (p=0.10). All cases were moderate. The sole thromboembolic event (0.4%) was a cerebral infarction in a patient in the non-antithrombotic group. Conclusions The rate of EUS-BD-related bleeding events was low. Even in patients receiving antithrombotic therapy, the bleeding event rates were not significantly different from those in patients not receiving antithrombotic therapy.

Background/Aims: The Japan Gastroenterological Endoscopy Society (JGES) has published guidelines for gastroenterological endoscopy in patients undergoing antithrombotic treatment. These guidelines classify endoscopic ultrasound-guided biliary drainage (EUS-BD) as a high-risk procedure. Nevertheless, the bleeding risk of EUS-BD in patients undergoing antithrombotic therapy is uncertain. Therefore, this study aimed to assess the bleeding risk in patients undergoing antithrombotic therapy. Methods: This single-center retrospective study included 220 consecutive patients who underwent EUS-BD between January 2013 and December 2018. We managed the withdrawal and continuation of antithrombotic agents according to the JGES guidelines. We compared the bleeding event rates among patients who received and those who did not receive antithrombotic agents. Results: A total of 18 patients (8.1%) received antithrombotic agents and 202 patients (91.8%) did not. Three patients experienced bleeding events, with an overall bleeding event rate of 1.3% (3/220): one patient was in the antithrombotic group (5.5%) and two patients were in the non-antithrombotic group (0.9%) (p=0.10). All cases were moderate. The sole thromboembolic event (0.4%) was a cerebral infarction in a patient in the non-antithrombotic group. Conclusions The rate of EUS-BD-related bleeding events was low. Even in patients receiving antithrombotic therapy, the bleeding event rates were not significantly different from those in patients not receiving antithrombotic therapy.

SUMMARY OF EVENT: Bacterial, mycotic peritonitis and Candida fungemia developed in a patient with moderate ascites who had undergone endoscopic ultrasound-guided biliary drainage (EUS-BD). Antibiotics and antifungal agent were administered and ascites drainage was performed. Although the infection improved, the patient's general condition gradually deteriorated due to aggravation of the primary cancer and he died. TEACHING POINT: This is the first report to describe infectious peritonitis after EUS-BD. Ascites carries the potential risk of severe complications. As such, in patients with ascites, endoscopic retrograde cholangiopancreatography (ERCP) is typically preferred over EUS-BD or percutaneous drainage to prevent bile leakage. However, ERCP may not be possible in some patients with tumor invasion of the duodenum or with surgically altered anatomy. Thus, in patients with ascites who require EUS-BD, we recommend inserting the drainage tube percutaneously and draining the ascites before and after the intervention in order to prevent severe infection.
Anti-Bacterial Agents ; Ascites ; Bile ; Candida ; Cholangiopancreatography, Endoscopic Retrograde ; Drainage ; Duodenum ; Endosonography ; Fungemia ; Humans ; Peritonitis