High-grade pancreatic intraepithelial neoplasia diagnosed based on changes in magnetic resonance cholangiopancreatography findings: A case report.

BACKGROUND: High-grade pancreatic intraepithelial neoplasia (PanIN) exhibits no mass and is not detected by any examination modalities. However, it can be diagnosed by pancreatic juice cytology from indirect findings. Most previous cases were diagnosed based on findings of a focal stricture of the main pancreatic duct (MPD) and caudal MPD dilatation and subsequent pancreatic juice cytology using endoscopic retrograde cholangiopancreatography (ERCP). We experienced a case of high-grade PanIN with an unclear MPD over a 20-mm range, but without caudal MPD dilatation on magnetic resonance cholangiopancreatography (MRCP). CASE SUMMARY: A 60-year-old female patient underwent computed tomography for a follow-up of uterine cancer post-excision, which revealed pancreatic cysts. MRCP revealed an unclear MPD of the pancreatic body at a 20-mm length without caudal MPD dilatation. Thus, course observation was performed. After 24 mo, MRCP revealed an increased caudal MPD caliber and a larger pancreatic cyst. We performed ERCP and detected atypical cells suspected of adenocarcinoma by serial pancreatic juice aspiration cytology examination. We performed a distal pancreatectomy and obtained a histopathological diagnosis of high-grade PanIN. Pancreatic parenchyma invasion was not observed, and curative resection was achieved. CONCLUSION: High-grade Pan-IN may cause MPD narrowing in a long range without caudal MPD dilatation.

Efficacy of a novel integrated biliary stent and nasobiliary catheter system for accidental tube deviation in biliary drainage.

Background and study aims Endoscopic nasobiliary drainage is accompanied by a risk of accidental removal of the nasobiliary drainage (NBD) tube, especially through self-removal in elderly patients. We studied the usefulness of an integrated biliary stent and nasobiliary catheter system (UMIDAS NB stent) for biliary drainage in case of accidental NBD tube removal. Patients and methods From April to November 2022, we placed a UMIDAS NB stent in 30 patients with acute cholangitis or obstructive jaundice. We evaluated the plastic stent (PS) position at the time of accidental stent removal and before the planned endoscopic procedure. In addition, we studied the ratio of successful biliary drainage and complications based on the usage of UMIDAS. Results All 11 patients with accidental stent removal exhibited correct PS position in X-ray fluoroscopy. Of the 19 patients with planned NBD tube removal, three had complete PS migration into the common bile duct and three had incomplete migration (the duodenal side flap entered the bile duct). In summary, 80% (24/30) of PS were in the correct position, and all patients had successful biliary drainage and no complications. Conclusions The UMIDAS NB stent might be useful for biliary drainage in patients with a high risk of NBD tube self-removal.

Clinical features and images of malignant lymphoma localized in the pancreatic head to differentiate from pancreatic ductal adenocarcinoma: a case series study.

BACKGROUND: Pathological examination by endoscopic ultrasonography-guided fine-needle aspiration (EUS-FNA) has been reported to be useful in diagnosing pancreatic malignant lymphoma (ML), but some ML cases are difficult to be differentiated from pancreatic ductal adenocarcinoma (PDAC). METHODS: This retrospective study included 8 patients diagnosed with ML that had a pancreatic-head lesion at initial diagnosis and 46 patients with resected PDAC in the pancreatic head between April 2006 and October 2021 at our institute. ML and PDAC were compared in terms of patients' clinical features and imaging examinations. RESULTS: The median tumor size was larger in ML than in PDAC (45.8 [24-64] vs. 23.9 [8-44] mm), but the median diameter of the caudal main pancreatic duct (MPD) was larger in PDAC (2.5 [1.0-3.5] vs. 7.1 [2.5-11.8] mm), both showing significant differences between these malignancies (both, P < 0.001). In the analysis of covariance, MLs showed a smaller caudal MPD per tumor size than PDACs, with a statistical difference (P = 0.042). Sensitivity and specificity using sIL-2R ≥ 658 U/mL plus CA19-9 < 37 U/mL for the differentiation of ML from PDAC were 80.0% and 95.6%, respectively. CONCLUSIONS: Diagnosing pancreatic ML using cytohistological examination through EUS-FNA can be difficult in some cases. Thus, ML should be suspected if a patient with a pancreatic tumor has a small MPD diameter per tumor size, high serum sIL-2R level, normal CA19-9 level. If the abovementioned features are present and still cannot be confirmed as PDAC, re-examination should be considered.

A case of pancreatic adenosquamous carcinoma with direct invasion to the gastrointestinal tract through the retention cyst wall: A rare case report.

A 62-year-old man presented with a 7-cm cystic lesion with irregularly thickened cyst wall in contact with the pancreatic tail. The pancreatic tail was described as hypoechoic on endoscopic ultrasonography. The cyst subsequently increased rapidly to 13 cm, and surgery was performed. This revealed adenosquamous carcinoma in the pancreatic tail to have invaded the stomach and transverse colon along the cyst wall. The cyst was diagnosed as a retention cyst due to pancreatic tail tumor. Invasion of nearby organs by a pancreatic cancer via the retention cyst wall is very rare, but it is necessary to keep the potential for such progress in mind.

The Deployment of a Newly Developed Proximal Release-Type Colonic Stent Is Feasible for Malignant Colorectal Obstruction near the Anal Verge: A Single-Center Preliminary Study.

INTRODUCTION: Colonic self-expandable metallic stents are widely used to treat malignant colorectal obstructions. Stent placement in lesions near the dentate line causes problems, including severe pain due to difficulty in positioning the stent accurately. Therefore, a proximal release-type stent was developed to overcome this issue, and this preliminary study aimed to investigate its efficacy and safety. PATIENTS AND METHODS: This research enrolled eight patients with malignant colorectal obstructions up to 10 cm from the anal verge who required placement of the newly developed proximal release-type colonic stent. The primary outcome was the clinical success rate, and the secondary outcomes were the technical success and adverse events rates. RESULTS: The technical and clinical success rates were 87.5% each, and the mean procedure time was 25.5 ± 22.0 min. The mean procedure time in the rectosigmoid colon was significantly longer than that in the rectum. Only one (12.5%) patient had stent migration, and neither anal pain nor tenesmus was observed. DISCUSSION: The stent was highly effective in treating lesions near the anal verge, and it might contribute to the expansion of indications for colorectal stents for lesions near the dentate line. However, the indications for rectosigmoid colon lesions should be cautiously considered.