Elastography used in endoscopic ultrasound (EUS)-elastography for pancreatic disease is roughly classified into strain elastography (SE) and shear wave elastography (SWE). Most of the previous studies have been performed using SE. Methods of interpreting the results of SE include recognizing the pattern of the image in the region of interest (ROI), using the SR (strain ratio) to compare the hardness of adipose tissue or connective tissue and the hardness of the lesion, and histogram analysis of the hardness distribution in the target lesion. The first two methods have poor reproducibility, require multiple evaluations, and require careful attention to interpretation of the results. These two methods have been used mainly for focal pancreatic diseases. Histogram analysis has excellent reproducibility and has been used for evaluation of chronic pancreatitis and for evaluating hardness distribution in similar lesions. Since the hardness of the pancreas increases with aging, it is necessary to consider the patientʼs age in the diagnosis of pancreatic disorders using EUS-elastography.

Granular cell tumors of the esophagus are generally benign tumors and occur in the mucosal lamina propria. We report a 59-year-old woman who presented with a granular cell tumor of the esophagus with adventitia invasion, despite being pathologically benign. She had been suffering from dysphagia for two years and then recently had begun to vomit. She was referred to our hospital after detection of an esophageal lesion in an upper gastrointestinal X-ray. Contrast-enhanced computed tomography and endoscopy identified an elevated lesion in the cervical esophagus, measuring 40mm, which was coated with normal mucosa. Endoscopic ultrasound-guided fine needle aspiration was performed under general anesthesia, but a definitive diagnosis could not be obtained. Therefore, incision biopsy was carried out and the retrieved specimen revealed stroma infiltrated by cells with eosinophilic cytoplasm of granular aspect. However, the central nuclei showed no evidence of atypia or mitotic figures and were immunohistochemically proven to be positive for S-100 protein. Although the pathological diagnosis was benign, thoracoscopic and laparoscopic subtotal esophagectomy was performed due to devastating dysphagia. In the mediastinal inlet, the tumor adhered partially but firmly to the tracheal membrane and she was finally diagnosed as having adventitia invasion pathologically. This case was pathologically benign, but met the diagnostic criteria for malignant granular cell tumor. If a granular cell tumor is much larger than the average size of granular cell tumors, the large granular cell tumor may invade the adventitia despite being pathologically benign. Surgical resection should be optimized to ensure the patient’s quality of life.

A 74-year-old woman was referred to our institute after undergoing a medical checkup during which barium meal examination identified the presence of wall irregularity at the greater curvature of the gastric body. Esophagogastroduodenoscopy (EGD) revealed an elevated submucosal tumor (SMT) -like lesion of 20 mm, and subsequent endoscopic ultrasonography showed a heterogeneous hypoechoic mass of 15 mm in diameter with clear borders in the second layer. Boring biopsy showed follicular and nodular lymphatic proliferations composed of small to medium-sized cells. Histopathological and immunohistochemical analyses resulted in the diagnosis of follicular lymphoma Grade 1. Imaging studies revealed Lugano Classification Stage Ⅰ. Radiotherapy at 30 Gy to the entire stomach was carried out, and EGD confirmed the presence of only a residual white scar at the corresponding location two months later. Event-free survival of one and one-half years has been observed at the time of this writing.

A 75-year-old man with a complaint of black stool and anemia was referred to our hospital. Endoscopic examination revealed a non-pedunculated polyp at the posterior aspect of the bulb with a small area of erosion and blood spot on the top, and we performed endoscopic hemostasis. Five weeks later, endoscopic ultrasound (EUS)-fine needle aspiration (FNA) revealed Brunnerʼs gland hyperplasia and the tissue from EUS-FNA was non-neoplastic. Four days after EUS-FNA, the patient developed black stool again, and we performed endoscopic hemostasis again. Because the lesion repeatedly hemorrhaged and because endoscopic resection of a non-pedunculated polyp at the posterior aspect of the bulb would be difficult, he underwent open duodenal submucosal dissection. The tumor was 25×25×10 mm, and histological analysis showed acinar cells, ducts and smooth muscles, leading to the diagnosis of Brunnerʼs gland hamartoma (BGH). In the past, according to the location of the lesion, pancreaticoduodenectomy was a choice for treatment when endoscopic resection of a hemorrhaging BGH would be difficult. Therefore, EUS-FNA is useful for preoperative diagnosis.

Case 1: A 64-year-old female with obstructive jaundice, suggesting the presence of pancreatic head tumor, was admitted to our hospital. Enhanced computed tomography (CT) showed a pancreatic head mass, while endoscopic ultrasound (EUS) detected two masses (i.e., pancreatic head and body). Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) was performed, and the two masses were identified as adenocarcinoma. The patient underwent subtotal stomach-preserving pancreatoduodenectomy. The pancreatic head and body masses were moderately and well differentiated adenocarcinoma, respectively. Case 2: A 78-year-old female was admitted to our hospital due to suspicion of a pancreatic body tumor. Enhanced CT showed a pancreatic tail mass, while EUS detected two masses (i.e., pancreatic body and tail). EUS-FNA was performed, and the two masses were identified as adenocarcinoma. The patient underwent distal pancreatectomy. Both masses were well differentiated adenocarcinoma, and could be distinguished histologically/morphologically. The use of preoperative EUS-FNA is necessary to confirm the presence of multiple lesions in patients with initial detection of a pancreatic mass.

For secure intraluminal closure, endoscopic hand-suturing (EHS), which involves continuous suturing by using a commercially-available barbed surgical suture and a through-the-scope-type flexible needle holder, has been introduced. This technique appears promising and useful for various situations including prevention of bleeding after endoscopic submucosal dissection as a strong and reliable tissue apposition method. The development, permeation and expansion of the indications of EHS are expected.

Hypotonic duodenography is an x-ray-based radiological imaging technique that uses an anticholinergic agent to suppress duodenal peristalsis. It is used not only for the qualitative and quantitative diagnosis of neoplastic lesions but also to clearly understand the overall image of a wide range of duodenal lesions, identify the exact wall location of the lesions, and assess the relationship of the lesions with the surrounding organs. An advantage of hypotonic duodenography is that it can provide detailed information to supplement endoscopic diagnoses. There are two variants of the test: tube-based methods that use a dedicated duodenal sonde for specialized examinations, and tubeless methods that involve the ingestion of a contrast agent. Generally, a barium preparation is used as the contrast agent and double-contrast imaging is performed. However, in patients who are at risk for severe constipation or intestinal obstruction, a water-soluble gastrointestinal contrast agent is used instead. The actual examination and interpretation should be performed after fully understanding the radiographic view of the normal duodenum. The normal duodenal mucosa is accompanied by a fine pattern of intestinal villi and Kerckringʼs folds. Moreover, it is important to be aware of the position and shape of the major duodenal papilla. During imaging, it is important to identify the wall of the target lesion and introduce barium onto it to acquire an image with good contrast.

Background and Aim: Endoscopic ultrasound-guided biliary drainage (EUS-BD) can be carried out by two different approaches: choledochoduodenostomy (CDS) and hepaticogastrostomy (HGS). We compared the efficacy and safety of these approaches in malignant distal biliary obstruction (MDBO) patients using a prospective, randomized clinical trial.

Methods: Patients with malignant distal biliary obstruction after failed endoscopic retrograde cholangiopancreatography were randomly selected for either CDS or HGS. The procedures were carried out at nine tertiary centers from September 2013 to March 2016. Primary endpoint was technical success rate, and the noninferiority of HGS to CDS was examined with a onesided significance level of 5%, where the noninferiority margin was set at 15%. Secondary endpoints were clinical success, adverse events (AE), stent patency, survival time, and overall technical success including alternative EUS-BD procedures.

Results: Forty-seven patients (HGS, 24; CDS, 23) were enrolled. Technical success rates were 87.5% and 82.6% in the HGS and CDS groups, respectively, where the lower limit of the 90% confidence interval of the risk difference was －12.2% (P=0.0278). Clinical success rates were 100% and 94.7% in the HGS and CDS groups, respectively (P=0.475). Overall AE rate, stent patency, and survival time did not differ between the groups. Overall technical success rates were 100% and 95.7% in the HGS and CDS groups, respectively (P=0.983).

Conclusions: This study suggests that HGS is not inferior to CDS in terms of technical success. When one procedure is particularly challenging, readily switching to the other could increase technical success.