Itaru Naitoh

Unilateral versus bilateral endoscopic metal stenting for malignant hilar biliary obstruction.

Background and Aim:  The extent of liver drainage for palliative treatment of malignant hilar biliary obstruction is controversial. The aim of this study was to compare endoscopic unilateral versus bilateral drainage in patients with malignant hilar biliary obstruction using a self‐expanding metal stent (SEMS).

Clinical significance of extrapancreatic lesions in autoimmune pancreatitis.

Objectives: To clarify the frequency and clinical significance of extrapancreatic lesions in autoimmune pancreatitis (AIP). Methods: The frequency and clinical characteristics of extrapancreatic lesions during the clinical course of AIP were investigated retrospectively in 64 patients with AIP. The predictive factors for relapse of AIP at clinical onset were also examined. Results: Extrapancreatic lesions occurred in 95% (61/64) during the clinical course of AIP. The frequencies of sclerosing cholangitis, sclerosing sialadenitis, retroperitoneal fibrosis, and mediastinal or hilar lymphadenopathy were 84% (54/64), 23% (15/64), 16% (10/64), and 77% (27/35), respectively. Patients with sclerosing sialadenitis or extrapancreatic bile duct sclerosing cholangitis had a significantly higher serum immunoglobulin G concentration than those without (P = 0.005 and P = 0.016, respectively). Univariate analysis revealed that sclerosing sialadenitis (P = 0.005), diffuse pancreatic ductal changes (P = 0.028), and a high serum immunoglobulin G concentration (P = 0.030) at clinical onset of AIP were significant predictive factors for relapse. Multivariate analysis revealed that diffuse pancreatic ductal changes (P = 0.005) and sclerosing sialadenitis (P = 0.012) were significant independent predictive factors for relapse of AIP. Conclusions: The frequency of extrapancreatic lesions with AIP during the clinical course was high. The presence of sclerosing sialadenitis at clinical onset is a significant predictive factor for relapse of AIP.

Diagnosis of IgG4-related sclerosing cholangitis.

IgG4-related sclerosing cholangitis (IgG4-SC) is often associated with autoimmune pancreatitis. However, the diffuse cholangiographic abnormalities observed in IgG4-SC may resemble those observed in primary sclerosing cholangitis (PSC), and the presence of segmental stenosis suggests cholangiocarcinoma (CC). IgG4-SC responds well to steroid therapy, whereas PSC is only effectively treated with liver transplantation and CC requires surgical intervention. Since IgG4-SC was first described, it has become a third distinct clinical entity of sclerosing cholangitis. The aim of this review was to introduce the diagnostic methods for IgG4-SC. IgG4-SC should be carefully diagnosed based on a combination of characteristic clinical, serological, morphological, and histopathological features after cholangiographic classification and targeting of a disease for differential diagnosis. When intrapancreatic stenosis is detected, pancreatic cancer or CC should be ruled out. If multiple intrahepatic stenoses are evident, PSC should be distinguished on the basis of cholangiographic findings and liver biopsy with IgG4 immunostaining. Associated inflammatory bowel disease is suggestive of PSC. If stenosis is demonstrated in the hepatic hilar region, CC should be discriminated by ultrasonography, intraductal ultrasonography, bile duct biopsy, and a higher cutoff serum IgG4 level of 182 mg/dL.

Establishment of a serum IgG4 cut-off value for the differential diagnosis of IgG4-related sclerosing cholangitis: A Japanese cohort

IgG4‐related sclerosing cholangitis (IgG4‐SC) must be precisely distinguished from primary sclerosing cholangitis and cholangiocarcinoma (CC) because the treatments are completely different. However, the pathological diagnosis of IgG4‐SC is difficult. Therefore, highly specific non‐invasive criteria such as serum IgG4 should be established. This study established a cut‐off for serum IgG4 to differentiate IgG4‐SC from respective controls using serum IgG4 levels measured in Japanese centers.

Diagnostic procedures for IgG4-related sclerosing cholangitis

Background/purposeIgG4-related sclerosing cholangitis (IgG4-SC) is one of several diseases associated with autoimmune pancreatitis (AIP). However, diffuse cholangraphic abnormalities seen in association with AIP may resemble those seen in primary sclerosing cholangitis (PSC), and the presence of segmental stenosis suggests cholangiocarcinoma. IgG4-SC responds well to steroid therapy, whereas in contrast, liver transplantation is the only effective therapy for PSC, and surgical intervention is also needed for cholangiocarcinoma. The aim of this review was to establish the diagnostic procedures for IgG4-SC.MethodsA literature search was conducted, covering English-language articles dealing with IgG4-SC published between 1991 and March 2010. As clinical data on IgG4-SC are limited, the author also took into consideration his own clinical experience with the treatment of IgG4-SC over a period of more than 19 years.ResultsWhen intrapancreatic stenosis is detected, pancreatic cancer should be ruled out. If multiple intrahepatic stenosis is evident, PSC should be discriminated on the basis of cholangiographic findings and liver biopsy with IgG4 immunostaining. An association with inflammatory bowel disease (IBD) is suggestive of PSC. If stenosis is demonstrated in the hepatic hilar region, cholangiocarcinoma should be discriminated by US, EUS, IDUS, and bile duct biopsy.ConclusionFor diagnosis of IgG4-SC, coexistence of AIP is the most useful finding. However, the most important consideration for clinicians is to be aware of IgG4-SC when encountering patients with obstructive jaundice.

Predictive factors for pancreatitis and cholecystitis in endoscopic covered metal stenting for distal malignant biliary obstruction

Pancreatitis and cholecystitis are major complications after self‐expandable metal stent (SEMS) placement in distal malignant biliary obstruction. We aimed to clarify predictive factors for pancreatitis and cholecystitis after covered SEMS placement.

Exophytic pedunculated gastrointestinal stromal tumor with remarkable cystic change

A 59-year-old man with bloody stools, and previously diagnosed with sigmoid colon carcinoma, visited our hospital. Preoperative abdominal ultrasonography (US) showed another tumor, with an uneven irregular surface, measuring about 9 × 5 cm, below the left hypochondrium. The tumor consisted of several cysts. Abdominal computed tomography (CT) showed a multicystic tumor attached to the stomach, and its septum and marginal region were intensely stained on contrast imaging. On magnetic resonance imaging (MRI), low and markedly high signals were revealed in the tumor on T1-weighted and T2-weighted sequences, respectively. Contrast imaging of the upper digestive tract showed extramural compression of the greater curvature of the antral stomach by the tumor. The tumor was partially imaged by endoscopic ultrasonography (EUS), but continuity to the stomach was not confirmed. On abdominal angiography, the tumor was slightly stained via the gastroepiploic arteries. Surgical treatment was performed to excise both the gastric tumor and the sigmoid colon carcinoma. The gastric tumor was removed with gastric wall tissue where the tumor was attached to a 2-cm pedicle. It was multicystic, contained watery fluid, and had a smooth outer surface. Histologically, the tumor consisted of multiple irregular cysts without epithelial lining, and solid epitheloid cell nests in between. The tumor cells had clear or eosinophilic cytoplasm and round nuclei. No mitotic figures were seen. The tumor cells in the pedicle were connected with the muscularis propriae of the stomach. Immunohistochemistry showed c-kit-positive, CD34-positive smooth muscle actin (SMA)-negative, and S-100-negative staining of tumor cells. The final diagnosis was gastrointestinal stromal tumor (GIST).

IgG4-related hepatic inflammatory pseudotumor with sclerosing cholangitis: a case report and review of the literature

IntroductionInflammatory pseudotumor is rare benign mass composed of chronic inflammatory cell infiltration and proliferating fibrous tissue. Some cases of inflammatory pseudotumor show abundant infiltrating IgG4-positive plasma cells and obliterative phlebitis, which are the pathologic hallmarks of autoimmune pancreatitis.Case presentationA 77-year-old Japanese man was admitted to our hospital because of epigastric pain. A solitary mass with delayed enhancement by dynamic computed tomography was present in the left hepatic lobe. Endoscopic retrograde cholangiography showed only segmental stenosis of the left intrahepatic bile duct. No abnormal findings were detected in the pancreas. The patient was clinically diagnosed as having intrahepatic cholangiocarcinoma and underwent surgery. Histological examination of the hepatic mass and bile duct wall showed abundant IgG4-positive plasma cell infiltration with obliterative phlebitis. The final diagnosis was IgG4-related hepatic inflammatory pseudotumor with sclerosing cholangitis. Delayed enhancement by computed tomography is a characteristic feature of IgG4-related inflammatory pseudotumor similar to that of autoimmune pancreatitis.ConclusionIgG4-related hepatic inflammatory pseudotumor unassociated with autoimmune pancreatitis should be one of the entities considered for differential diagnosis of liver tumors. Delayed enhancement on computed tomography might be useful finding for diagnosing IgG4-related hepatic inflammatory pseudotumor.

Comparison of intraductal ultrasonography findings between primary sclerosing cholangitis and IgG4-related sclerosing cholangitis

Comparisons of intraductal ultrasonography (IDUS) findings between primary sclerosing cholangitis (PSC) and IgG4‐related sclerosing cholangitis (IgG4‐SC) have not been elucidated. We aimed to clarify the differences in transpapillary IDUS findings between PSC and IgG4‐SC.

Clinical differences between mass-forming autoimmune pancreatitis and pancreatic cancer

Abstract Objective. Autoimmune pancreatitis (AIP) needs to be differentiated from pancreatic cancer (PC). We aimed to clarify the findings specific for AIP by comparing the clinical differences between mass-forming AIP and PC. Material and methods. We retrospectively compared 36 patients with mass-forming AIP and 60 with PC without metastasis regarding clinical, imaging, serological, histological differences and other organ involvement (OOI). We evaluated the sensitivity, specificity and accuracy of these findings for the differential diagnosis between AIP and PC. Results. The findings 100% specific for AIP were a capsule-like rim on computed tomography (CT), skipped lesion of main pancreatic duct (MPD) on endoscopic retrograde pancreatography (ERP) or magnetic resonance cholangiopancreatography (MRCP), γ-globulin > 2 g/dl, OOI (extrapancreatic biliary stricture, salivary gland swelling and retroperitoneal fibrosis) and ruling out PC by histopathological findings of endoscopic ultrasonography-guided fine-needle aspiration. The findings over 90% specific were IgG4 > 280 mg/dl (98%), IgG > 1800 mg/dl (97%), maximal diameter of upstream MPD < 5 mm on MRCP (95%) and IgG4 > 135 mg/dl (94%), respectively. Conclusions. Clinical, imaging, serological, histological findings and OOI differed between mass-forming AIP and PC. Capsule-like rim on CT, skipped lesion of MPD on ERP or MRCP, IgG4 > 280 mg/dl, and OOI were highly specific findings for AIP. These findings are useful in the differential diagnosis of mass-forming AIP from PC.