Mixed neuroendocrine-non-neuroendocrine neoplasm of the bile duct with long-term prognosis after neoadjuvant chemotherapy.

A 74-year-old man with obstructive jaundice presented with a thickened distal bile duct wall. A transpapillary forceps biopsy revealed an adenocarcinoma; however, because the tumor image was different from that of a typical cholangiocarcinoma, endoscopic ultrasound-guided fine-needle aspiration was performed on the tumor and enlarged lymph nodes. The tumor cells were positive for synaptophysin and CD56 with a Ki67 labeling index of 95%, and he was diagnosed with small cell neuroendocrine carcinoma. We diagnosed a bile duct tumor with neuroendocrine carcinoma component with lymph node metastasis. Preoperative chemotherapy for neuroendocrine carcinoma was administered because R0 resection was difficult and the risk of postoperative recurrence was high. Three courses of chemotherapy with carboplatin and etoposide resulted in marked tumor shrinkage, and radical resection was performed 3 months after diagnosis. Postoperative pathology revealed adenocarcinoma in the mucosal epithelium and small cell neuroendocrine carcinoma in the submucosa, most of which resolved with chemotherapy. Carboplatin and etoposide were resumed as adjuvant chemotherapy, and 67 months of recurrence-free survival were achieved after surgery.

A case of young male with recurrent acute pancreatitis caused by an intrapancreatic gastric duplication cyst.

Gastric duplication cyst (GDC) is a rare gastrointestinal malformation that frequently occurs in the greater curvature of the gastric antrum or corpus. Herein, we reported a case of intrapancreatic GDC found as a result of recurring pancreatitis. A 15-year-old man experienced repeated episodes of acute pancreatitis and was found to have a cystic lesion in the pancreatic tail. Contrast-enhanced computed tomography revealed a 20-mm cystic lesion with an enhanced thick wall. Endoscopic ultrasonography revealed an anechoic cyst with a three-layered wall. Magnetic resonance cholangiopancreatography and endoscopic retrograde pancreatography (ERP) revealed a connection between the cyst and the main pancreatic duct (MPD), and the duplication of the MPD. ERP showed the pancreatic duct stenosis downstream of the cyst. Although preoperative diagnosis was difficult, distal pancreatectomy was performed to prevent recurrence of pancreatitis. Pathological examination revealed that the cystic lesion was circumferentially surrounded by the pancreatic parenchyma. The epithelial lining of the cyst was crypt epithelium containing the fundic or pyloric glands and surrounded by a smooth muscle layer. The final diagnosis was intrapancreatic GDC.

A case of congenital biliary dilatation without pancreaticobiliary maljunction, so-called Type Ib according to Todani's classification.

Congenital biliary dilatation (CBD) is a congenital malformation of focal dilatation of the extrahepatic bile ducts, including the common bile duct, and is often associated with pancreaticobiliary maljunction (PBM). In this article, we report a CBD case that presented with focal dilation of the common bile duct without PBM (Todani's classification type Ib). The patient was a 32-year-old man who visited a doctor with a chief complaint of abdominal distension. Computed tomography revealed cystic dilatation of the common bile duct, and the patient was referred to our institution. Magnetic resonance cholangiopancreatography showed cystic dilatation of the common bile duct with a maximum diameter of 7 cm; however, evaluating the presence of PBM was challenging. Endoscopic ultrasonography showed small gallstones and debris in the dilated common bile duct and no thickening of the gallbladder wall. Endoscopic retrograde cholangiopancreatography revealed no PBM or markedly elevated bile amylase levels. Based on these findings, the patient was diagnosed with Todani Type Ib CBD. Since this patient did not have pancreatobiliary reflux, it was unclear whether the risk of developing biliary tract cancer was high, and since the treatment was highly invasive, the decision was to follow up without surgical treatment.

The Significance of Histopathological Findings on Clinical Outcomes in Endoscopic Papillectomy with Endocut.

This study aimed to evaluate primary clinical outcomes in patients who underwent endoscopic papillectomy (EP) using the Endocut mode while examining the pathological characteristics of the margin of the resected specimen. To this end, 70 patients who underwent Endocut EP were included. Resection margins were classified according to pathological findings as "negative", "positive", or "uncertain (difficult pathological evaluation)". The effect of pathological resection margins on residual tumor recurrence rates was evaluated. The median follow-up was 47 months (range, 22-84). Eleven patients (15.7%) were diagnosed with residual tumors, ten of whom were diagnosed within 6 months after EP. The resection margins were pathologically negative in 27 patients, positive in 15, and uncertain in 28; residual tumors occurred in 5 patients (33.3%) in the positive group, 5 (17.9%) in the uncertain group, and 1 (3.7%) in the negative group. The patient in the negative group had familial adenomatous polyposis (FAP). Female sex, FAP, and uncertain or positive resection margins were significantly more common in residual patients (p = 0.009, 0.044, and 0.041, respectively). Pathological resection margins can be used to infer the residual tumor incidence, leading to early post-treatment of residual tumors.

Utility of Covered Self-Expanding Metal Stents for Biliary Drainage during Neoadjuvant Chemotherapy in Patients with Borderline Resectable Pancreatic Cancer.

OBJECTIVES: We aimed to compare the utility of covered self-expanding metal stents (CSEMSs) with that of plastic stents (PSs) for biliary drainage during neoadjuvant chemotherapy in patients with borderline resectable pancreatic cancer. METHODS: Forty patients with borderline resectable pancreatic cancer underwent biliary stenting during neoadjuvant chemotherapy at Hiroshima University Hospital. PSs and CSEMSs were placed in 19 and 21 patients, respectively. Two gemcitabine-based regimens for chemotherapy were used. Treatment outcomes and postoperative complications were compared between both groups. RESULTS: The incidence of recurrent biliary obstruction was significantly lower in the CSEMS group (0% vs. 47.4%, p < 0.001), and the median time to recurrent biliary obstruction in the PS group was 47 days. There was no difference in the incidence of other complications such as non-occlusive cholangitis, pancreatitis, and cholecystitis between the two groups. Delays in the chemotherapy schedule due to stent-related complications were significantly frequent in the PS group (52.6% vs. 4.8%, p = 0.001). There was no significant difference in the incidence of postoperative complications between the two groups. CONCLUSIONS: CSEMSs may be the best choice for safely performing neoadjuvant chemotherapy for several months in patients with borderline resectable pancreatic cancer with bile duct stricture.

Relapse rate and predictors of relapse after cessation of glucocorticoid maintenance therapy in type 1 autoimmune pancreatitis: a multicenter retrospective study.

BACKGROUND: Type 1 autoimmune pancreatitis responds well to glucocorticoid therapy with a high remission rate. Moreover, glucocorticoid maintenance therapy can help prevent relapse. However, the relapse rate following cessation of long-term glucocorticoid therapy is unknown. The aim of this study was to clarify the relapse rate and predictors of relapse following long-term glucocorticoid therapy cessation. METHODS: We analyzed 94 patients who achieved remission after undergoing glucocorticoid therapy, discontinued treatment after at least 6 months of maintenance therapy, and were subsequently followed up for at least 6 months. The patients were divided into three groups based on treatment duration (< 18, 18-36, and ≥ 36 months), and their relapse rates were compared. Univariate and multivariate analyses of clinical factors were conducted to identify relapse predictors. RESULTS: After discontinuing glucocorticoid therapy, relapse was observed in 43 (45.7%) patients, with cumulative relapse rates of 28.2% at 1 year, 42.1% at 3 years, 47.0% at 5 years, and a plateau of 77.6% at 9 years. Of the 43 patients who relapsed, 25 (58.1%) relapsed within 1 year after after cessation of glucocorticoid therapy. Relapse and cumulative relapse rates did not differ significantly according to treatment duration. In the multivariate analysis, an elevated serum IgG4 level at the time of glucocorticoid cessation was found to be an independent predictor of relapse (hazard ratio, 4.511; p < 0.001). CONCLUSIONS: A high relapse rate occurred after cessation of glucocorticoid maintenance therapy, regardless of the duration of maintenance therapy, especially within the first year after cessation. However, the normalization of long-term serum IgG4 levels may be a factor in considering cessation.

Diagnostic Ability and Safety of Repeated Pancreatic Juice Cytology Using an Endoscopic Nasopancreatic Drainage Catheter for Pancreatic Ductal Adenocarcinoma: A Multicenter Prospective Study.

Pathological examination is essential for the diagnosis and treatment of pancreatic ductal adenocarcinoma (PDAC). Moreover, a reliable pathological diagnosis is extremely important for improving prognosis, especially in early-stage PDAC. This study prospectively evaluated the usefulness of repeated pancreatic juice cytology (PJC) using an endoscopic nasopancreatic drainage (ENPD) catheter for the diagnosis of PDAC. We enrolled 82 patients suspected of having resectable PDAC, based on imaging studies, and judged the necessity for cytology. The diagnostic yield of up to six repeated PJCs and the incidence of complications, such as pancreatitis, was evaluated. A total of 60 patients were diagnosed with PDAC. The overall sensitivity and specificity were 46.7% and 95.5%, respectively. The cumulative positivity rate increased with the number of sampling sessions, reaching 58.3% in the sixth session. The sensitivity was significantly higher in the pancreatic head than in the pancreatic tail (p = 0.043). Additionally, it was 100% in four patients with a tumor size ≤10 mm. Pancreatitis occurred in six patients (7.3%), all of whom were treated conservatively. In the diagnosis of PDAC, repeated PJC using an ENPD catheter revealed a cumulative effect of sensitivity up to six times and an excellent diagnostic yield for small PDAC.

A case of middle-aged male with multicentric solid pseudopapillary neoplasm of the pancreas.

Solid pseudopapillary neoplasm (SPN) of the pancreas is a low-grade, malignant pancreatic tumor that occurs predominantly in young females. In this report, an extremely rare case of multicentric SPNs in a middle-aged male is discussed. A 55-year-old man was incidentally found to have a mass in the pancreatic body on abdominal ultrasonography during a medical checkup. Contrast-enhanced computed tomography (CT) revealed masses with 50-mm and 25-mm diameters with internal calcification in the pancreatic body and tail, respectively. These masses had a gradually increasing enhancement pattern though the center of the pancreatic body mass and the periphery of the pancreatic tail lesion were non-enhancing. Magnetic resonance imaging revealed a hyperintense signal in the mass of the pancreatic tail suggestive of hemorrhage on T1-weighted imaging. Positron emission tomography-CT revealed abnormal uptake of fluorodeoxyglucose in both lesions. Endoscopic ultrasound-guided fine needle aspiration was performed on both lesions, and tumor tissue with a solid proliferation of poorly pleomorphic small cells was observed. The tumor cells were positive for CD10 in the cytoplasm and ß-catenin in the nucleus. The patient was diagnosed with SPNs and underwent a successful distal pancreatectomy.

A case of unresectable intrahepatic cholangiocarcinoma with a germline BRCA1 mutation.

Intrahepatic cholangiocarcinoma (ICC) is a malignant liver tumor with poor prognosis. Various mutations in cancer-predisposing genes have been reported in ICC, and germline BRCA1/2 mutations, which are the causative genes for hereditary breast and ovarian cancer syndrome (HBOC), have been reported in many patients with ICC. Here, we report a case of unresectable ICC with a germline BRCA1 mutation. A 73-year-old man was found to have a mass in the left lobe of the liver on abdominal ultrasonography during a medical check-up and was referred to our institution. Contrast-enhanced computed tomography revealed a 30-mm mass with a delayed enhancement pattern, tumor invasion into the major blood vessels, and enlarged regional lymph nodes. Ultrasound-guided percutaneous tumor biopsy revealed a well-differentiated adenocarcinoma, and the patient was diagnosed with clinical Stage IIIB ICC. Systemic chemotherapy with gemcitabine and cisplatin was initiated because of the unresectable nature of the disease. Regarding family history, his eldest daughter was diagnosed with HBOC with a germline BRCA1 mutation at the time of breast cancer surgery, and she developed pancreatic cancer seven years later. The patient underwent BRCA1 single-site analysis and was diagnosed with HBOC with a germline BRCA1 mutation.

Optimal indication of endoscopic retrograde pancreatography-based cytology in the preoperative pathological diagnosis of pancreatic ductal adenocarcinoma.

BACKGROUND: Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is extremely useful for pathological diagnosis of pancreatic ductal adenocarcinoma (PDAC); however, puncturing is difficult in some cases, and there is a risk of needle tract seeding. This study evaluated the indications for endoscopic retrograde pancreatography-based (ERP)-based cytology for the preoperative diagnosis of PDAC. METHODS: This study included 267 patients with PDAC who underwent preoperative ERP. The diagnostic performance of ERP-based cytology for PDAC was evaluated based on the sample collection method (pancreatic juice cytology [PJC] during ERP, brush cytology, PJC via endoscopic nasopancreatic drainage [ENPD] catheter), lesion site (pancreatic head, body/tail), and lesion size (≤10 mm, 10-20 mm, >20 mm), and compared with the diagnostic performance of EUS-FNA. RESULTS: The overall sensitivity of ERP-based cytology was 54.9%; sensitivity by the sampling method was 34.7% for PJC during ERP, 65.8% for brush cytology, and 30.8% for PJC via an ENPD catheter. The sensitivity of EUS-FNA was 85.3%. Brush cytology and PJC via an ENPD catheter were performed more often in pancreatic body/tail lesions than in head lesions (P = 0.016 and P < 0.001, respectively), and the overall sensitivity of ERP-based cytology was better for body/tail lesions (63.2% vs. 49.0%, P = 0.025). The sensitivities of ERP-based cytology and EUS-FNA in diagnosing PDAC ≤10 mm were 92.3% and 33.3%, respectively. Post-ERP pancreatitis was observed in 22 patients (8.2%) and significantly less common with ENPD catheters (P = 0.002). CONCLUSIONS: ERP-based cytology may be considered the first choice for pathological diagnosis of PDAC ≤10 mm and in the pancreatic body/tail.

Pembrolizumab-induced Focal Pancreatitis Diagnosed by Endoscopic Ultrasound-guided Fine-needle Aspiration.

A 69-year-old man with advanced non-small-cell lung cancer was treated with pembrolizumab for 4 months. Three months after pembrolizumab was discontinued, computed tomography showed enlargement of the pancreatic head, with hypoattenuating areas in the pancreatic head to body. On endoscopic ultrasonography, the entire pancreatic parenchyma was hypoechoic. Endoscopic retrograde cholangiopancreatography showed narrowing of the main pancreatic duct at the pancreatic head. Endoscopic ultrasound-guided fine-needle aspiration showed inflammatory cell infiltration in the stroma but no neoplastic lesions. CD8-positve T cells were dominant over CD4-positive T cells in the infiltrating lymphocytes, and the patient was diagnosed with pembrolizumab-induced pancreatitis.

Pathological Features and Imaging Findings in Pancreatic Carcinoma In Situ.

OBJECTIVES: This study aimed to evaluate the pathological features and imaging findings of pancreatic carcinoma in situ (PCIS). METHODS: Twenty patients with PCIS were categorized as flat (F) (n = 6) and low papillary (LP) (n = 14) types. RESULTS: None of F type and 8 (57%) of 14 with LP type lesions showed intraductal infiltrations of the main pancreatic duct (MPD) greater than 10 mm. None of F type and 3 (21%) of 14 with LP type lesions showed skip lesions in the MPD. Magnetic resonance cholangiopancreatography showed irregular MPD stenoses in 5 (83%) of 6 with F and 13 (100%) of 13 with LP type lesions. Magnetic resonance cholangiopancreatography determined that the median lengths of the irregular MPD stenoses were 3.6 mm for F, and 11.6 mm for LP type lesions. Endoscopic retrograde cholangiopancreatography determined that the median lengths of the irregular MPD stenoses were 2.8 mm for F, and 14.3 mm for LP type lesions. Pancreatic cancer recurrences limited to the remnant pancreas occurred in 2 patients with LP type lesions. CONCLUSIONS: In LP type PCIS, intraductal infiltration of the MPD occurs frequently. There may be multiple lesions, and lesions may recur in the remnant pancreas. Long-term strict follow-up assessments should be implemented for LP type PCIS.

Clinical Analysis of Early-Stage Pancreatic Cancer and Proposal for a New Diagnostic Algorithm: A Multicenter Observational Study.

Early diagnosis of pancreatic ductal adenocarcinoma (PDAC) is challenging but essential for improving its poor prognosis. We established a multicenter study to clarify the clinicopathological features, and to propose new algorithm for early diagnosis of PDAC. Ninety-six patients with stage 0 and IA PDAC were enrolled from 13 high-volume centers. Overall, 70% of the patients were asymptomatic. The serum pancreatic enzyme levels were abnormal in half of the patients. The sensitivity of endoscopic ultrasonography (EUS) for detecting small PDAC was superior to computed tomography and magnetic resonance imaging (MRI) (82%, 58%, and 38%, respectively). Indirect imaging findings were useful to detect early-stage PDAC; especially, main pancreatic duct stenosis on MRI had the highest positive rate of 86% in stage 0 patients. For preoperative pathological diagnosis, the sensitivity of endoscopic retrograde cholangiopancreatography (ERCP)-associated pancreatic juice cytology was 84%. Among the stage IA patients, EUS-guided fine-needle aspiration revealed adenocarcinoma in 93% patients. For early diagnosis of PDAC, it is essential to identify asymptomatic patients and ensure close examinations of indirect imaging findings and standardization of preoperative pathological diagnosis. Therefore, a new diagnostic algorithm based on tumor size and imaging findings should be developed.

Role of Endoscopic Ultrasonography and Endoscopic Retrograde Cholangiopancreatography in the Diagnosis of Pancreatic Cancer.

Pancreatic cancer has the poorest prognosis among all cancers, and early diagnosis is essential for improving the prognosis. Along with radiologic modalities, such as computed tomography (CT) and magnetic resonance imaging (MRI), endoscopic modalities play an important role in the diagnosis of pancreatic cancer. This review evaluates the roles of two of those modalities, endoscopic ultrasonography (EUS) and endoscopic retrograde cholangiopancreatography (ERCP), in the diagnosis of pancreatic cancer. EUS can detect pancreatic cancer with higher sensitivity and has excellent sensitivity for the diagnosis of small pancreatic cancer that cannot be detected by other imaging modalities. EUS may be useful for the surveillance of pancreatic cancer in high-risk individuals. Contrast-enhanced EUS and EUS elastography are also useful for differentiating solid pancreatic tumors. In addition, EUS-guided fine needle aspiration shows excellent sensitivity and specificity, even for small pancreatic cancer, and is an essential examination method for the definitive pathological diagnosis and treatment decision strategy. On the other hand, ERCP is invasive and performed less frequently for the purpose of diagnosing pancreatic cancer. However, ERCP is essential in cases that require evaluation of pancreatic duct stricture that may be early pancreatic cancer or those that require differentiation from focal autoimmune pancreatitis.

The role of apparent diffusion coefficient value in the diagnosis of localized type 1 autoimmune pancreatitis: differentiation from pancreatic ductal adenocarcinoma and evaluation of response to steroids.

PURPOSE: The aim of this study was to clarify the usefulness of the apparent diffusion coefficient (ADC) value in the differential diagnosis of localized autoimmune pancreatitis (AIP) and pancreatic ductal adenocarcinoma (PDAC) and the evaluation of response to steroids. METHODS: This study retrospectively analyzed 40 patients with localized AIP and 71 patients with PDAC who underwent abdominal MRI with DWI (b = 0 and 1000 s/mm2). Their ADC values at the lesion sites and five MRI findings useful for diagnosing AIP were evaluated. In addition, ADC values before and after steroid therapy were compared in 28 patients with localized AIP. RESULTS: The median ADC value was significantly lower for localized AIP than for PDAC (1.057 × 10-3 vs 1.376 × 10-3 mm2/s, P < 0.001). In the ROC curve analysis, the area under the curve was 0.957 and optimal cut-off value of ADC for differentiating localized AIP from PDAC was 1.188 × 10-3 mm2/s. ADC value ≤ 1.188 × 10-3 mm2/s showed the highest sensitivity and accuracy among the MRI findings (92.6% and 90.7%, respectively), and when combined with one or more other MRI findings, showed 96.3% specificity. The median ADC values before and after steroid therapy (mean 7.9 days) were 1.061 × 10-3 and 1.340 × 10-3 mm2/s, respectively, and ADC values were significantly elevated after steroid induction (P < 0.001). CONCLUSION: The measurement of ADC values was useful for the differential diagnosis of localized AIP and PDAC and for the early determination of the effect of steroid therapy.

Usefulness of peroral cholangioscopy in the differential diagnosis of IgG4-related sclerosing cholangitis and extrahepatic cholangiocarcinoma: a single-center retrospective study.

BACKGROUND: In the diagnosis of IgG4-related sclerosing cholangitis (IgG4-SC), differentiation from extrahepatic cholangiocarcinoma (ECC) is extremely important but is still a clinical challenge. This study aimed to elucidate the usefulness of peroral cholangioscopy (POCS) for the differential diagnosis between IgG4-SC and ECC. METHODS: POCS findings for bile duct stricture were retrospectively evaluated in 17 patients with IgG4-SC diagnosed at the Hiroshima University Hospital and 53 patients with surgically resected infiltrating ECC. Mucosal surface, dilated vessels (tortuosity, caliber alteration, and disruption), and easily bleeding were compared between the groups. RESULTS: The stricture sites of IgG4-SC evaluated by POCS were 10 extrapancreatic bile ducts and 9 intrapancreatic bile ducts. In patients with IgG4-SC, smooth mucosal surface was observed in 89% (17/19), dilated vessels in 58% (11/19) [tortuosity 82% (9/11), caliber alteration 18% (2/11), and disruption 9% (1/11)], and easily bleeding in 0%. Irregular mucosal surface and easily bleeding were observed significantly more frequently in ECC (both P <  0.001). The frequency of caliber alteration and disruption of dilated vessels was significantly less in IgG4-SC (P <  0.001 and 0.005, respectively). The sensitivity and specificity of POCS in the diagnosis of ECC were 96 and 89%, respectively. Dilated vessels in IgG4-SC were observed significantly more frequently in the extrapancreatic bile duct, especially the hilar bile duct (P = 0.006). Concerning image evaluation, the interobserver agreement was κ = 0.719, and the intraobserver agreement was κ = 0.768 and 0.754. CONCLUSIONS: Characteristic POCS findings of the stricture sites in IgG4-SC were smooth mucosal surface, dilated vessels without caliber alteration and disruption, and lack of easily bleeding. These POCS findings are extremely useful for distinguishing between IgG4-SC and ECC.

Investigation of Fluorodeoxyglucose Positron Emission Tomography for the Diagnosis of Solid Pseudopapillary Neoplasm of the Pancreas: A Study Associated With a National Survey of Solid Pseudopapillary Neoplasms.

OBJECTIVES: This study aimed to investigate the utility of fluorodeoxyglucose (FDG) positron emission tomography for solid pseudopapillary neoplasm (SPN) diagnosis. METHODS: The subjects included 53 cases of SPN. We compared the maximal standardized uptake volume (SUVmax) with those of 25 cases of pancreatic duct cancer and 18 cases of pancreatic neuroendocrine neoplasm. In addition, immunopathological testing for SPN with regard to FDG uptake was undertaken. RESULTS: An increase in SUVmax was observed in all tumors with increased tumor diameter. Among tumors of 20 mm or smaller, the SUVmax of SPN was significantly higher than those of pancreatic duct cancer and pancreatic neuroendocrine neoplasm. The results of a pathological study of FDG uptake in SPN revealed increased glucose transporter protein type 1 expression with tumor enlargement. Furthermore, increased hypoxia-inducible factor-1 and vascular endothelial growth factor expression under hypoxic conditions were observed in the areas of necrosis. CONCLUSIONS: In cases in which high FDG uptake is observed in small pancreatic tumors, FDG positron emission tomography is potentially useful for SPN differentiation. The factors involved in FDG uptake in SPN include cell density and glucose transporter protein expression, as well as hypoxia-inducible factor and vascular endothelia growth factor expression in the hypoxic environment of necrotic areas.

Prospective Follow-up Study of the Recurrence of Pancreatic Cancer Diagnosed at an Early Stage: The Value of Endoscopic Ultrasonography for Early Diagnosis of Recurrence in the Remnant Pancreas.

OBJECTIVES: Most patients with pancreatic cancer (PC) demonstrate recurrences in the form of metastatic disease. We prospectively evaluated recurrence in PC cases diagnosed at an early stage. METHODS: Thirty cases of PC stage 0 or IA were prospectively followed for at least 1 year after initial surgery. We performed blood tests and contrast-enhanced computed tomography (CT) every 3 to 6 months. Endoscopic ultrasonography (EUS) was performed if CT revealed abnormal findings in the remnant pancreas (RP). RESULTS: The median follow-up period was 53.9 months. Pancreatic cancer recurred in the RP (n = 8) and liver (n = 1). Computed tomography revealed mass lesions in 5 cases, a cystic lesion in 2 cases, and pancreatic duct dilatation in 1 case. Endoscopic ultrasonography detected mass lesions in 3 cases without a detectable mass on CT. The sensitivity of EUS-guided fine-needle aspiration and pancreatic juice cytology was 75%. Five of 8 cases underwent total resection of the RP, with pathologic findings revealing stage IA in 1 case, stage II in 1 case, and stage III in 3 cases. CONCLUSIONS: Careful long-term follow-up including EUS should be performed in resected PC cases diagnosed at an early stage to check recurrence in the RP.

A case of collagenous colitis associated with novel oral anticoagulants use.

An 84-year-old man was referred to our hospital because of watery diarrhea. Due to cerebral infarction, he had started treatment with a novel oral anticoagulants (NOAC) 1 month prior to admission. The patient underwent blood tests, enhanced computed tomography, and colonoscopy, which indicated infectious or medicinal colitis. The diarrhea persisted and he developed hypokalemia, so a second colonoscopy was performed, which showed edematous mucosa. Colonic mucosal biopsies showed a thick collagen band in the subepithelial region, and collagenous colitis was diagnosed. The watery diarrhea subsequently resolved 1 week after changing the NOAC to warfarin. Reports on collagenous colitis caused by NOAC are very rare, and we consider this case valuable.