Prediction of Microsatellite Instability in Colorectal Cancer Using a Machine Learning Model Based on PET/CT Radiomics

Purpose@#We investigated the feasibility of preoperative 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET)/ computed tomography (CT) radiomics with machine learning to predict microsatellite instability (MSI) status in colorectal cancer (CRC) patients. @*Materials and Methods@#Altogether, 233 patients with CRC who underwent preoperative FDG PET/CT were enrolled and divided into training (n=139) and test (n=94) sets. A PET-based radiomics signature (rad_score) was established to predict the MSI status in patients with CRC. The predictive ability of the rad_score was evaluated using the area under the receiver operating characteristic curve (AUROC) in the test set. A logistic regression model was used to determine whether the rad_score was an independent predictor of MSI status in CRC. The predictive performance of rad_score was compared with conventional PET parameters. @*Results@#The incidence of MSI-high was 15 (10.8%) and 10 (10.6%) in the training and test sets, respectively. The rad_score was constructed based on the two radiomic features and showed similar AUROC values for predicting MSI status in the training and test sets (0.815 and 0.867, respectively; p=0.490). Logistic regression analysis revealed that the rad_score was an independent predictor of MSI status in the training set. The rad_score performed better than metabolic tumor volume when assessed using the AUROC (0.867 vs. 0.794, p=0.015). @*Conclusion@#Our predictive model incorporating PET radiomic features successfully identified the MSI status of CRC, and it also showed better performance than the conventional PET image parameters.

Current Practice Patterns of Endoscopic Ultrasound-Guided Tissue Sampling for Pancreatic Solid Mass in Korea: Outcomes of a National Survey

Background/Aims@#Although endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) and fine needle biopsy (FNB) are widely used for tissue acquisition of pancreatic solid mass, the optimal strategy of this procedure has not been established yet. The aim of this nationwide study was to investigate the current practice patterns of EUS-FNA/FNB for pancreatic solid mass in Korea. @*Methods@#The Policy-Quality Management of the Korean Pancreatobiliary Association (KPBA) developed a questionnaire containing 22 questions. An electronic survey consisting of the questionnaire was distributed by e-mail to members registered to the KPBA. @*Results@#A total of 101 respondents completed the survey. Eighty respondents (79.2%) performed preoperative EUS-FNA/FNB for operable pancreatic solid mass. Acquire needles (60.4%) were used the most, followed by ProCore needles (47.5%). In terms of need size, most respondents (>80%) preferred 22-gauge needles regardless of the location of the mass. Negative suction with a 10-mL syringe (71.3%) as sampling technique was followed by stylet slow-pull (41.6%). More than three needle passes for EUS-FNA/FNB was performed by most respondents (>80%). The frequency of requiring repeated procedure was significantly higher in respondents with a low individual volume (<5 per month, p=0.001). Prophylactic antibiotics were routinely used in 39 respondents (38.6%); rapid on-site pathologic evaluation was used in 6.1%. @*Conclusions@#According to this survey, practices of EUS-FNA/FNB for pancreatic solid mass varied substantially, some of which differed considerably from the recommendations present in existing guidelines. These results suggest that the development of evidence-based quality guidelines fitting Korean clinical practice is needed to establish the optimal strategy for this procedure.

National Survey Regarding the Management of Difficult Bile Duct Stones in South Korea

Background/Aims@#This study aimed to investigate the patterns of preferred endoscopic procedure types and techniques for managing difficult common bile duct (CBD) stones in South Korea. @*Methods@#The Committee of Policy and Quality Management of Korean Pancreatobiliary Association (KPBA) conducted a survey containing 19 questions. Both paper and online surveys were carried out; with the paper survey being conducted during the 2019 Annual Congress of KPBA and the online survey being conducted through Google Forms from April 2020 to February 2021. @*Results@#The response rate was approximately 41.3% (86/208). Sixty-two (73.0%) worked at tertiary hospitals or academic medical centers, and 60 (69.7%) had more than 5 years of endoscopic retrograde cholangiopancreatography experience. The preferred size criteria for large CBD stones were 15 mm (40.6%), 20 mm (31.3%), and 30 mm (4.6%). For managing of large CBD stones, endoscopic papillary large balloon dilation after endoscopic sphincterotomy was the most preferred technique (74.4%). When performing procedures in those with bleeding diathesis, 64 (74.4%) respondents favored endoscopic papillary balloon dilation (EPBD) alone or EPBD with small endoscopic sphincterotomy. Fifty-five respondents (63.9%) preferred the doubleguidewire technique when faced with difficult bile duct cannulation in patients with periampullary diverticulum. In surgically altered anatomies, cap-fitted forward viewing endoscopy (76.7%) and percutaneous transhepatic cholangioscopy (48.8%) were the preferred techniques for Billroth-II anastomosis and total gastrectomy with Roux-en-Y anastomosis, respectively. @*Conclusions@#Most respondents showed unifying trends for the management of difficult CBD stones. The current practice patterns could be used as basic data for clinical quality improvements in the management of difficult CBD stones.

Current trends in the management of pancreatic cystic neoplasms in Korea: a national survey

Background/Aims@#The study aimed to investigate the current practice patterns in the management of pancreatic cystic neoplasms in Korea. @*Methods@#An electronic survey was systematically distributed by email to members of the Korean Pancreatobiliary Association from December 2019 to February 2020. @*Results@#In total, 115 (110 gastroenterologists, five surgeons) completed the survey, 72.2% of whom worked in a tertiary/academic medical center. Most (65.2%) followed the 2012/2017 International Association of Pancreatology guidelines for the management of pancreatic cystic neoplasms. A gadolinium-enhanced magnetic resonance imaging/magnetic resonance cholangiopancreatography was the most common first-line diagnostic modality (42.1%), but a contrast-enhanced computed tomography scan was preferred as a subsequent surveillance tool (58.3%). Seventy- four percent of respondents routinely performed endoscopic ultrasound-guided fine needle aspiration for pancreatic cystic neoplasms with suspicious mural nodules. Endoscopic ultrasound-guided fine needle aspiration cytology (94.8%) and cystic fluid carcinoembryonic antigen (95.7%) were used for cystic fluid analysis. Most (94%) typically recommended surgery in patients with high-risk stigmata, but 18.3% also considered proceeding with surgery in patients with worrisome features. Most (96.5%) would continue surveillance of pancreatic cystic neoplasms for more than 5 years. @*Conclusions@#According to this survey, there was variability in the management of pancreatic cystic neoplasms among the respondents. These results suggest that the development of evidence-based guidelines for pancreatic cystic neoplasms that fit the Korean practice is needed to create an optimal approach to the management of pancreatic cystic neoplasms.

A National Survey on the Environment and Basic Techniques of Endoscopic Retrograde Cholangiopancreatography in Korea

Background/Aims@#The work environment in which endoscopic retrograde cholangiopancreatography (ERCP) is conducted has influence on its efficacy and safety. We aimed to assess the current status of ERCP work environments and to investigate the trends associated with the basic techniques of ERCP in Korea. @*Methods@#The work environment and information on the basic techniques of ERCP were acquired by the Korean Pancreatobiliary Association (KPBA) through a national survey in 2019. The survey was performed at the KPBA conference in 2019. The contents of survey comprised of the current environment of ERCP, preparation before ERCP, and the preferred basic techniques used in ERCP. @*Results@#Completed questionnaires were returned from 84 KPBA members. The mean ERCP volume per year was approximately 500. About 60% (50/84) reported that they worked with a dedicated ERCP team with experienced nurses. Two-thirds (57/84, 68%) answered that they had a fluoroscopy room used solely for ERCP procedures. All respondents intravenously hydrated the patient to prevent post-ERCP pancreatitis (84/84, 100%). The preferred procedural sedations were balanced propofol sedation (50%) and midazolam-only sedation (47%). Wire-guided cannulation was most commonly used for selective cannulation (81%). Endoscopic retrograde biliary drainage was preferred over endoscopic nasobiliary drainage (60% vs 22%). The initial method of ampullary intervention was endoscopic sphincterotomy in 60%. @*Conclusions@#Data from the survey involving a large number of Korean ERCP doctors revealed considerable variabilities with regard to the work environment and basic techniques of ERCP in Korea. The study provides information regarding the current trends of ERCP that can be used to establish ERCP standards in Korea.

Vascular Uptake on 18F-FDG PET/CT During the Clinically Inactive State of Takayasu Arteritis Is Associated with a Higher Risk of Relapse

Purpose@#To evaluate whether vascular uptake on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18F-FDG PET/CT) during the clinically inactive state of Takayasu arteritis (TAK) is associated with disease relapse. @*Materials and Methods@#Patients with TAK who underwent 18F-FDG PET/CT during the clinically inactive state of the disease between 2006 and 2019 were included. Clinically inactive disease was defined as a status not fulfilling the National Institutes of Health (NIH) criteria for active disease in TAK. Relapse was defined as recurrence of clinically active disease after a clinically inactive period, requiring change in the treatment regimen. Vascular uptake on 18F-FDG PET/CT was assessed using target/background ratio (TBR), calculated as arterial maximum standardized uptake value (SUV)/mean SUV in venous blood pool. Multivariable Cox regression analysis was performed to identify factors associated with relapse. @*Results@#A total of 33 patients with clinically inactive TAK were included. During a median observation period of 4.5 (0.9–8.1) years, relapse occurred in 9 (27.3%) patients at median 1.3 (0.7–6.9) years. Notably, TBR [1.5 (1.3–1.8) vs. 1.3 (1.1–1.4), p=0.044] was significantly higher in patients who relapsed than in those who did not. On multivariable Cox regression analysis, the presence of NIH criterion 2 [adjusted hazard ratio (HR): 7.044 (1.424–34.855), p=0.017] and TBR [adjusted HR: 11.533 (1.053–126.282), p=0.045] were significantly associated with an increased risk of relapse. @*Conclusion@#Vascular uptake on 18F-FDG PET/CT and the presence of NIH criterion 2 are associated with future relapse in patients with clinically inactive TAK.

Vascular Uptake on 18F-FDG PET/CT During the Clinically Inactive State of Takayasu Arteritis Is Associated with a Higher Risk of Relapse

Purpose@#To evaluate whether vascular uptake on 18 F-fluorodeoxyglucose positron emission tomography/computed tomography ( 18F-FDG PET/CT) during the clinically inactive state of Takayasu arteritis (TAK) is associated with disease relapse. @*Materials and Methods@#Patients with TAK who underwent 18F-FDG PET/CT during the clinically inactive state of the disease between 2006 and 2019 were included. Clinically inactive disease was defined as a status not fulfilling the National Institutes of Health (NIH) criteria for active disease in TAK. Relapse was defined as recurrence of clinically active disease after a clinically inactive period, requiring change in the treatment regimen. Vascular uptake on 18F-FDG PET/CT was assessed using target/background ratio (TBR), calculated as arterial maximum standardized uptake value (SUV)/mean SUV in venous blood pool. Multivariable Cox regression analysis was performed to identify factors associated with relapse. @*Results@#A total of 33 patients with clinically inactive TAK were included. During a median observation period of 4.5 (0.9–8.1) years, relapse occurred in 9 (27.3%) patients at median 1.3 (0.7–6.9) years. Notably, TBR [1.5 (1.3–1.8) vs. 1.3 (1.1–1.4), p=0.044] was significantly higher in patients who relapsed than in those who did not. On multivariable Cox regression analysis, the presence of NIH criterion 2 [adjusted hazard ratio (HR): 7.044 (1.424–34.855), p=0.017] and TBR [adjusted HR: 11.533 (1.053–126.282), p=0.045] were significantly associated with an increased risk of relapse. @*Conclusion@#Vascular uptake on 18F-FDG PET/CT and the presence of NIH criterion 2 are associated with future relapse in patients with clinically inactive TAK.

Management of Pain, Exocrine and Endocrine Insufficiency in Chronic Pancreatitis / 대한췌담도학회지

Chronic pancreatitis is the progressive and inflammatory disease which will result in the irreversible destruction and fibrosis of the pancreas. These processes cause chronic pain and pancreatic dysfunctions such as exocrine and endocrine insufficiency. Medical treatment for chronic pancreatitis would be reviewed in this article. Abdominal pain should be accessed by using multidimensional approach including pain intensity, pattern, impact on daily function and quality of life. Abstinence from alcohol and smoking should be strong recommendation. The guideline for analgesic therapy follows the principles of the “pain relief ladder” by World Health Organization. The pancreatic enzyme replacement should be considered when exocrine insufficiency is suspected. Enteric-coated microspheres or mini-microspheres of <2 mm in size with a minimum lipase dose of 40,000–50,000 United States Pharmacopeia are the recommended preparations. These preparations should be taken with main meals. Increasing the oral enzyme dose and the addition of a proton pump inhibitor could be considered in cases of unsatisfactory clinical response. Diabetes mellitus secondary to chronic pancreatitis is classified as Type IIIc diabetes mellitus. Optimal pharmacological treatment has not been established yet but should promote life-style changes, which may improve glucose control and avoid hypoglycemia. In patients with severe malnutrition, insulin therapy is recommended as a first choice. Treatment for chronic pancreatitis can include medication, therapeutic endoscopy, interventional radiology, and surgery. Among them, medical treatment is the most important and should be well understood.

Primary Pancreatic Diffuse Large B-Cell Lymphoma Involving the Stomach / 대한내과학회지

Primary pancreatic lymphoma (PPL) is extremely rare, comprising fewer than 1% of non-Hodgkin lymphomas. The most common histological subtype of PPL is diffuse large Bcell lymphoma (DLBCL). A 46-year-old man presented with indigestion, epigastric pain, and weight loss for 2 months. Abdominal computed tomography showed a well-defined hypodense mass located at the pancreas head involving the stomach, as well as enlargement of several mesenteric and perigastric lymph nodes. Histological examination was performed by upper gastrointestinal endoscopy of the stomach and endoscopic ultrasound-guided fine-needle aspiration and biopsy of the pancreatic mass. Histology of the pancreatic mass and the stomach revealed pancreatic DLBCL, involving the stomach. The patient received chemotherapy and is currently in complete remission. We report a rare presentation of DLBCL, appearing as a primary pancreatic tumor involving the stomach, which we presume is the first such report in South Korea.

Refeeding Syndrome as a Possible Cause of Very Early Mortality in Acute Pancreatitis

BACKGROUND/AIMS: Refeeding syndrome (RFS) is a fatal clinical complication that can occur as a result of fluid and electrolyte shifts during early nutritional rehabilitation for malnourished patients. This study was conducted to determine the clinical implications of RFS in patients with acute pancreatitis (AP). METHODS: Between 2006 and 2016, AP patients with very early mortality were retrospectively enrolled from three university hospitals. RESULTS: Among 3,206 patients with AP, 44 patients died within 3 days after diagnosis. The median age was 52.5 years (range, 27 to 92 years), male-to-female ratio was 3:1, and median duration from admission to death was 33 hours (range, 5 to 72 hours). The etiology of AP was alcohol abuse in 32 patients, gallstones in five patients, and hypertriglyceridemia in two patients. Ranson score, bedside index for severity of AP, and acute physiology and chronic health evaluation-II were valuable for predicting very early mortality (median, [range]; 5 [1 to 8], 3 [0 to 5], and 19 [4 to 45]). RFS was diagnosed in nine patients who died of septic shock (n=5), cardiogenic shock (n=2), or cardiac arrhythmia (n=2). In addition, patients with RFS had significant hypophosphatemia compared to non-RFS patients (2.6 mg/dL [1.3 to 5.1] vs 5.8 mg/dL [0.8 to 15.5]; p=0.001). The early AP-related mortality rate within 3 days was approximately 1.4%, and RFS occurred in 20.5% of these patients following sudden nutritional support. CONCLUSIONS: The findings of current study emphasize that clinicians should be aware of the possibility of RFS in malnourished AP patients with electrolyte imbalances.

Factors Associated with Malignant Biliary Strictures in Patients with Atypical or Suspicious Cells on Brush Cytology

BACKGROUND/AIMS: Pathological diagnosis of biliary strictures with atypical or suspicious cells on endoscopic retrograde brush cytology and indeterminate strictures on imaging is challenging. The aim of this study was to identify markers for malignant strictures in such cases. METHODS: We retrospectively analyzed data collected from 146 consecutive patients with indeterminate biliary strictures on imaging who underwent endoscopic retrograde brush cytology from 2007 to 2013. Factors associated with malignant strictures in patients with atypical or suspicious cells on brush cytology were identified. RESULTS: Among the 67 patients with a malignant disease (48 cholangiocarcinoma, 6 gallbladder cancer, 5 pancreatic cancer, 5 ampulla of Vater cancer, and 3 other types), 36 (53.7%) had atypical or suspicious cells on brush cytology. Among these, the factors that independently correlated with malignant strictures were stricture length (odds ratio [OR], 5.259; 95% confidence interval [CI], 1.802– 15.294) and elevated carbohydrate antigen 19-9 (CA19-9) (OR, 3.492; 95% CI, 1.242–9.815), carcinoembryonic antigen (CEA) (OR, 4.909; 95% CI, 1.694–14.224), alkaline phosphatase (ALP) (OR, 3.362; 95% CI, 1.207–9.361), and gamma-glutamyl transpeptidase (rGT) (OR, 4.318; 95% CI, 1.512–12.262). CONCLUSIONS: Elevated levels of CA19-9, CEA, ALP, and rGT and stricture length are associated with malignant strictures in patients with indeterminate biliary strictures on imaging and atypical or suspicious cells on brush cytology.

Significance of Metabolic Tumor Volume and Total Lesion Glycolysis Measured Using ¹⁸F-FDG PET/CT in Locally Advanced and Metastatic Gallbladder Carcinoma

PURPOSE: This study aimed to determine the prognostic value of new quantitative parameters of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT), including metabolic tumor volume (MTV), in patients with locally advanced and metastatic gallbladder cancer (GBC). MATERIALS AND METHODS: In total, 83 patients initially diagnosed with locally advanced and metastatic GBC and who underwent 18F-FDG PET/CT at the time of initial diagnosis were retrospectively reviewed. The metabolic volume-based PET parameters of primary tumors and metastatic lesions were measured, including maximum and average standardized uptake values (SUV), MTV, and total lesion glycolysis. An overall survival (OS) analysis was performed using the Kaplan-Meier method with PET and clinical parameters. A Cox proportional hazards regression analysis was performed to determine independent prognostic factors. RESULTS: In univariate analysis, pathologic differentiation (p<0.001), performance status (PS; p=0.003), C-reactive protein (CRP) level (p=0.009), and PET-related SUVmt max (the highest SUV among the metastatic lesions) (p=0.040) and MTVtotal (the sum of the MTVs of both the primary and metastatic lesions) (p=0.031), were significant for OS. In multivariate analysis, MTVtotal (hazard ratio: 2.07; 95% confidence interval: 1.23–3.48; p=0.006) remained significant for the prediction of OS, as did differentiation (p=0.001), PS (p=0.001), and CRP (p=0.039). CONCLUSION: In locally advanced and metastatic GBC, volume-based PET/CT parameters of the total tumor burden of malignancy, such as MTVtotal, were found to be useful for the identification of patients with poor prognosis.

Clinical Significance of Urinary Neutrophil Gelatinase-associated Lipocalin Levels in Defining the Various Etiologies of Acute Kidney Injury in Liver Cirrhosis Patients / 대한소화기병학회잡지

BACKGROUND/AIMS: A diagnosis of hepatorenal syndrome (HRS) is based on a differential evaluation of acute kidney injury (AKI), which may aggravate the clinical course. This study assessed the clinical significance of the urinary neutrophil gelatinase-associated lipocalin (u-NGAL) levels in a differential diagnosis of AKI in patients with liver cirrhosis (LC). METHODS: Patients with LC who developed AKI were enrolled prospectively. Clinically, patients with AKI were classified into prerenal azotemia (PRA), HRS, and acute tubular necrosis (ATN) groups. RESULTS: Fifty-five patients (male, 74.5%) with LC who exhibited AKI upon admission were enrolled; 28, 9, and 18 patients were included in the PRA, HRS, and ATN groups, respectively. The baseline model for end-stage liver disease (MELD) scores was similar in the subgroups. The median event creatinine level, measured at the time of the AKI diagnosis, was similar in the HRS and ATN subgroups. On the other hand, the median event u-NGAL level differed significantly between the three subgroups (PRA, HRS, and ATN: 37 vs. 134 vs. 2,625 ng/mL, p=0.003). In particular, the median u-NGAL level of the HRS group was clearly different from those of the PRA (p<0.001) and ATN (p<0.001) groups. Multivariable analysis revealed the natural logarithm of the u-NGAL level (hazard ratio [HR] 1.77, p=0.031) and the MELD score (HR 1.17, p=0.027) to be independent prognostic factors for in-hospital mortality in patients with LC and AKI. CONCLUSIONS: The median u-NGAL level differentiated HRS from ATN and served as a clinical indicator of in-hospital mortality for patients with LC and AKI.

Clinical Significance of Urinary Neutrophil Gelatinase-associated Lipocalin Levels in Defining the Various Etiologies of Acute Kidney Injury in Liver Cirrhosis Patients / 대한소화기학회지

BACKGROUND/AIMS: A diagnosis of hepatorenal syndrome (HRS) is based on a differential evaluation of acute kidney injury (AKI), which may aggravate the clinical course. This study assessed the clinical significance of the urinary neutrophil gelatinase-associated lipocalin (u-NGAL) levels in a differential diagnosis of AKI in patients with liver cirrhosis (LC).METHODS: Patients with LC who developed AKI were enrolled prospectively. Clinically, patients with AKI were classified into prerenal azotemia (PRA), HRS, and acute tubular necrosis (ATN) groups.RESULTS: Fifty-five patients (male, 74.5%) with LC who exhibited AKI upon admission were enrolled; 28, 9, and 18 patients were included in the PRA, HRS, and ATN groups, respectively. The baseline model for end-stage liver disease (MELD) scores was similar in the subgroups. The median event creatinine level, measured at the time of the AKI diagnosis, was similar in the HRS and ATN subgroups. On the other hand, the median event u-NGAL level differed significantly between the three subgroups (PRA, HRS, and ATN: 37 vs. 134 vs. 2,625 ng/mL, p=0.003). In particular, the median u-NGAL level of the HRS group was clearly different from those of the PRA (p<0.001) and ATN (p<0.001) groups. Multivariable analysis revealed the natural logarithm of the u-NGAL level (hazard ratio [HR] 1.77, p=0.031) and the MELD score (HR 1.17, p=0.027) to be independent prognostic factors for in-hospital mortality in patients with LC and AKI.CONCLUSIONS: The median u-NGAL level differentiated HRS from ATN and served as a clinical indicator of in-hospital mortality for patients with LC and AKI.

Large Cell Neuroendocrine Carcinoma of the Extrahepatic Bile Duct / 대한소화기학회지

Primary neuroendocrine tumors originating from the extrahepatic bile duct are rare. Among these tumors, large cell neuroendocrine carcinomas (NECs) are extremely rare. A 59-year-old man was admitted to Sanggye Paik Hospital with jaundice that started 10 days previously. He had a history of laparoscopic cholecystectomy, which he had undergone 12 years previously due to chronic calculous cholecystitis. Laboratory data showed abnormally elevated levels of total bilirubin 15.3 mg/dL (normal 0.2–1.2 mg/dL), AST 200 IU (normal 0–40 IU), ALT 390 IU (normal 0–40 IU), and gamma-glutamyl transferase 1,288 U/L (normal 0–60 U/L). Serum CEA was normal, but CA 19-9 was elevated 5,863 U/mL (normal 0–37 U/mL). Abdominal CT revealed a 4.5 cm sized mass involving the common bile duct and liver hilum and dilatation of both intrahepatic ducts. Percutaneous transhepatic drainage in the left hepatic duct was performed for preoperative biliary drainage. The patient underwent radical common bile duct and Roux-en-Y hepaticojejunostomy for histopathological diagnosis and surgical excision. On histopathological examination, the tumor exhibited large cell NEC (mitotic index >20/10 high-power field, Ki-67 index >20%, CD56 [+], synaptophysin [+], chromogranin [+]). Adjuvant concurrent chemotherapy and radiotherapy were started because the tumor had invaded the proximal resection margin. No recurrence was detected at 10 months by follow-up CT.

Clinical Interpretation of Elevated CA 19-9 Levels in Obstructive Jaundice Following Benign and Malignant Pancreatobiliary Disease / 대한소화기학회지

BACKGROUND/AIMS: Elevated carbohydrate antigen (CA) 19-9 level may be unable to differentiate between benign and malignant pancreatobiliary disease with obstructive jaundice. The study aims to determine the clinical interpretation and the diagnostic value of CA 19-9 level in pancreatobiliary diseases with coexistent obstructive jaundice. METHODS: We retrospectively reviewed the data of 981 patients who underwent biliary drainage due to obstructive jaundice following pancreatobiliary disease at Sanggye Paik Hospital for 5 years. 114 patients with serial follow-up data for CA 19-9 level were included in this study (80 patients with malignancy and 34 patients with benign diseases). We compared the levels of CA 19-9 levels and the biochemical value before and after biliary drainage. RESULTS: The rate of CA 19-9 elevation (>37 U/mL) was significantly different between the benign group and the malignant group (59% vs. 90%, p=0.001). Despite the decrease in serum bilirubin after biliary drainage, CA 19-9 levels remained elevated in 12% of patients in the benign group and in 63% of patients in the malignant group (p<0.001). Finally, 12% of patients in the benign group turned out to have malignant disease. A receiver operating characteristic analysis provided a cut-off value of 38 U/mL for differentiating benign disease from malignant disease after biliary drainage (area under curve, 0.787; 95% confidence interval, 0.703 to 0.871; sensitivity, 62%; specificity, 88%). CONCLUSIONS: This study suggested that we should consider the possibility of malignant causes if the CA 19-9 levels remain high or are more than 38 U/mL after resolution of biliary obstruction.

Multiple Myeloma Mimics Bone Metastasis From a Rectal Adenocarcinoma

A presumptive diagnosis of bone metastasis can be easily made when a patient with a history of colorectal cancer develops bone lesions that are seen on follow-up imaging. In this case report, we describe a patient whose multiple bone lesions were wrongly attributed to a recurrence of rectal cancer rather than being identified as multiple myeloma lesions. When clinicians detect new, abnormal, bony lesions in a patient with a previous history of cancer, they should consider diseases such as multiple myeloma in their differential diagnosis.

Diagnostic Value of Endoscopic Ultrasonography in Symptomatic Patients with High and Intermediate Probabilities of Common Bile Duct Stones and a Negative Computed Tomography Scan

BACKGROUND/AIMS: When computed tomography (CT) does not indicate choledocholithiasis in highly suspicious patients, there is no definite consensus on the subsequent modality. Endoscopic ultrasonography (EUS) indicates fewer procedure-related complications than endoscopic retrograde cholangiopancreatography (ERCP) and has a lower cost than magnetic resonance cholangiopancreatography. Therefore, we aimed to investigate the diagnostic value of EUS in patients with suspected choledocholithiasis and negative CT findings. METHODS: Between March 2008 and November 2014, we retrospectively evaluated 200 patients with negative CT findings and high or intermediate probabilities of choledocholithiasis. All patients initially underwent EUS followed by ERCP as a confirmatory criterion standard. The primary outcome in these patients was the accuracy of EUS in the detection of choledocholithiasis. The secondary outcome was the clinical prediction of common bile duct (CBD) stones in this group. RESULTS: EUS indicated choledocholithiasis in 165 of the 200 patients, and ERCP confirmed choledocholithiasis in 161 patients (80.5%). The accuracy of EUS in the detection of choledocholithiasis was 94.0% (sensitivity, 97.5%; specificity, 79.5%; positive predictive value, 95.2%; negative predictive value, 88.6%). A multivariate analysis demonstrated that choledocholithiasis was strongly predicted by EUS detection of choledocholithiasis, an age >55 years and a clinical diagnosis of cholangitis. CONCLUSIONS: An EUS-first approach is recommended for patients with suspected CBD stones and negative CT findings.

An Aggressive Natural Killer Cell Lymphoma Presenting as Acute Liver Failure with Ascites / 대한내과학회지

Acute liver failure (ALF) is a medical emergency triggering an urgent need for liver transplantation. The most common causes of ALF are drug- and virus-associated hepatitis, but hematological malignancies such as an aggressive natural killer cell lymphoma (ANKL) can uncommonly cause ALF. A 50 year-old male presented with ascites, jaundice, and encephalopathy. The ascitic fluid had a serum-ascites albumin gradient of 0.3 g/L, and contained atypical lymphocytes, which were positive for CD3. Computed tomography revealed mild hepatomegaly and multiple nodules in both lobes of the liver. A liver biopsy showed that the liver parenchyma had been infiltrated by malignant lymphoid cells, and exhibited marked sinusoidal dilatation. Immunohistochemically, the lymphoid cells were positive for CD3, CD56, and Epstein-Barr virus-encoded small RNA. The patient was diagnosed with ANKL causing ALF, and died on hospital day 12. This case shows that infiltration of the liver with ANKL can (rarely) cause ALF.

Efficacy and Safety of Infliximab Therapy and Predictors of Response in Korean Patients with Crohn's Disease: A Nationwide, Multicenter Study

PURPOSE: Infliximab is currently used for the treatment of active Crohn's disease (CD). We aimed to assess the efficacy and safety of infliximab therapy and to determine the predictors of response in Korean patients with CD. MATERIALS AND METHODS: A total of 317 patients who received at least one infliximab infusion for active luminal CD (n=198) and fistulizing CD (n=86) or both (n=33) were reviewed retrospectively in 29 Korean referral centers. Clinical outcomes of induction and maintenance therapy with infliximab, predictors of response, and adverse events were evaluated. RESULTS: In patients with luminal CD, the rates of clinical response and remission at week 14 were 89.2% and 60.0%, respectively. Male gender and isolated colonic disease were associated with higher remission rates at week 14. In week-14 responders, the probabilities of sustained response and remission were 96.2% and 93.3% at week 30 and 88.0% and 77.0% at week 54, respectively. In patients with fistulizing CD, clinical response and remission were observed in 85.0% and 56.2% of patients, respectively, at week 14. In week-14 responders, the probabilities of sustained response and remission were 94.0% and 97.1%, respectively, at both week 30 and week 54. Thirty-nine patients (12.3%) experienced adverse events related to infliximab. Serious adverse events developed in 19 (6.0%) patients including seven cases of active pulmonary tuberculosis. CONCLUSION: Infliximab induction and maintenance therapy are effective and well tolerable in Korean patients with luminal and fistulizing CD. However, clinicians must be aware of the risk of rare yet critical adverse events.