Yasutaka Okayama

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).

Intracystic hemorrhage of a simple liver cyst mimicking a biliary cystadenocarcinoma

Simple liver cysts are rarely complicated by intracystic hemorrhage. We encountered a case of simple liver cyst that was morphologically similar to biliary cystadenocarcinoma, which was complicated by asymptomatic intracystic hemorrhage and successfully treated by right lobectomy. A large cystic lesion of the liver was detected in a 57-year-old woman during a mass screening health check. Abdominal ultrasonography (US) revealed that the cystic lesion, containing many hyperechoic papillary structures, occupied almost the entire region of the right hepatic lobe. In addition, a round mural nodule, measuring approximately 5 cm in diameter, was detected in the cystic wall. Abdominal computed tomography (CT) revealed that the inner part of the cystic lesion showed homogeneous low density, but CT did not show the round nodule detected by US. On T1-weighted sequence of magnetic resonance imaging (MRI), the lesion showed homogeneous high signals, together with a low-signal tumorous lesion in the cystic wall. T2-weighted sequence of MRI showed unhomogeneous high signals, together with high signals in the tumorous part. These findings did not exclude the possibility of a malignant cystic tumor, such as biliary cystadenocarcinoma. Therefore, right lobectomy was performed. Histological examinations of resected tissue specimens revealed that the lesion was a liver cyst containing a large amount of blood clot, and that the tumorous lesion detected by US and MRI was a large mass of blood clot which was partly liquefied. This case indicates the diagnostic importance of the morphological discordance between CT and US or MRI findings for liver cyst containing a large amount of blood clot.

Intrahepatic biliary papilloma morphologically similar to biliary cystadenoma

Abstract  A 37‐year‐old man presented complaining of epigastralgia. Abdominal ultrasonography revealed the presence of a papillary tumor (9 mm in diameter) in the cystic lesion (18 mm in diameter) in hepatic segment 4, which was accompanied by mild intrahepatic bile duct dilatation. Although abdominal computed tomography also showed the cystic lesion, it did not show papillary tumors inside the lesion. Endoscopic retrograde cholangiography showed the communication between the cystic lesion and the left hepatic duct. In addition, mucus was observed in the common bile duct. When transpapillary intraductal ultrasonography was performed through the left hepatic duct using a fine ultrasonic probe, a hyperechoic papillary and lobulated tumor was clearly shown in the cystic lesion. The wall of the cyst was smooth and there was no sign of tumor infiltration. Based on these findings, biliary cystadenoma was diagnosed and an extended left lobectomy was carried out. However, pathological findings postoperatively revealed that the lesion was a localized biliary papilloma, developing and extending to the intrahepatic duct. This case is rare and there have been no published reports describing a biliary papilloma morphologically similar to biliary cystadenoma.

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).

Tauro-β-muricholate preserves choleresis and prevents taurocholate-induced cholestasis in colchicine-treated rat liver.

In recent clinical and animal experimental studies, ursodeoxycholic acid (UDCA) has been noted to have marked choleretic and cytoprotective actions. To define the mechanism and determine whether such favorable influence is specific to UDCA, the choleretic action of beta-muricholic acid (beta-MCA), which has a similar chemical structure, was studied using an isolated rat-liver-perfusion system. As a result, beta-MCA and taurine-conjugated beta-MCA (T beta-MCA) stimulated bile flow accompanied by elevation of bile acid output and phospholipid output, and beta-MCA caused an elevation in biliary HCO3- concentration in normal rat livers. After colchicine treatment, taurocholic acid (TCA) administration was associated with marked cholestasis while both beta-MCA and T beta-MCA still increased bile flow under the same conditions. Furthermore, simultaneous administration of beta-MCA or, more markedly, T beta-MCA reversed the effects of TCA alone in colchicine-treated rat liver; significant preventive effects against the cholestasis could be shown. These data suggest that beta-MCA and especially T beta-MCA can support choleresis even under conditions of colchicine-dependent microtubule dysfunction. The effects of T beta-MCA on organelle lipids and their intracellular transport may differ from those of TCA, presumably because of the anticholestatic and cytoprotective effects of T beta-MCA.

A solid cystic tumor of the pancreas with ossification and possible malignancy, coexisting nonfusion of the pancreatic ducts.

We report the case of a 34-year-old woman with a solid cystic tumor (SCT) of the pancreas accompanied by ossification and possible malignancy, coexisting nonfusion of the pancreatic ducts. There was a 24 x 29 x 33-mm mass with a prominent calcified lesion in the tail of the pancreas detected by abdominal ultrasonography, computed tomography, and magnetic resonance imaging. There were no distal metastases detected. Endoscopic retrograde pancreatography revealed nonfusion of the pancreatic ducts. The resected tumor consisted of solid and cystic components. The tumor was not encapsulated and included a severely ossified lesion inside. On microscopy, the tumor cells were small, eosinophilic, and proliferated in a solid or pseudo-papillary pattern. The tumor cells infiltrated into the surrounding normal pancreas parenchyma and invaded part of the mesentery. The immunostaining was positive for alpha-1-antitrypsin, neuron-specific enolase, vimentin, and chromogranin A. In the literature, only a few cases of SCT of the pancreas described ossification. As far as we know, only three cases of SCT of the pancreas, which demonstrated nonfusion of the pancreatic ducts, have been reported. Thus, SCT of the pancreas with ossification, possible malignancy, and coexisting nonfusion of the pancreatic ducts is extremely rare.

Rupture of hepatic aneurysm complicating hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu disease) for which hepatic arterial coil embolization was effective.

A 74‐year‐old woman was transferred to our hospital for further examinations because of abdominal fullness and abnormal levels of serum liver/biliary enzyme persisting for 3 weeks. She had anemia and dilatation of many capillary vessels in her fingers, palms, and tongue in addition to reporting frequent incidences of nasal bleeding in herself and her family. Abdominal ultrasonography detected a cystic lesion in the right hepatic lobe, connected to a dilated tortuous hepatic artery. A low‐echoic hepatic phyma was also detected in the back of the cystic lesion. Abdominal computed tomography and magnetic resonance imaging indicated that the cystic lesion was an aneurysm and the low‐echoic phyma was a hematoma. Hepatic arteriography confirmed a hepatic aneurysm, tortuous dilatation of the hepatic artery, and the complication of an arteriovenous shunt in the liver. Taking all of these findings into consideration, this case was diagnosed as hereditary hemorrhagic telangiectasia (HTT) complicated by a hepatic aneurysm causing intrahepatic hematoma. To prevent re‐rupture of the aneurysm, we performed a hepatic arterial coil embolization. After therapy, no blood flow to the aneurysm was detected by ultrasonic color Doppler method and the hematoma gradually diminished. There have been no reports of a case in which hepatic arterial embolization was effective for HHT‐associated hepatic aneurysm causing intrahepatic hematoma. This very rare case provides important clinical information regarding abdominal vascular complications of HTT and a less invasive treatment for them.

Efficacy of plastic tube stents without side holes for middle and lower biliary strictures.

Background Although biliary expandable metallic stents (EMS) improve patency, they are unsuitable for primary biliary stenting. Although plastic tube stents without side holes (PWOS) are also reported to prolong patency, their efficacy remains controversial. Goals To evaluate clinical utility and relative advantages, we reviewed clinical results of three types of stents: plastic tube stents with side holes (PS), PWOS, and EMS. Study The 130 patients comprised 56 with pancreatic cancers, 26 with gallbladder cancers, 21 with bile duct cancers, and 27 with other malignant diseases. Plastic tube stents with side holes (10 French [Fr]), PWOS (10 Fr), and EMS (30 Fr) were inserted in 64, 28, and 38 cases, respectively. Results Overall cumulative stent patency rates for EMS and PWOS groups were significantly higher than that of PS. This was also the case with middle and lower biliary tract strictures and with pancreas cancers. In Japan, medical costs with endoscopic retrograde cholangiopancreatography (

A Case of Purulent Pancreatic Ductitis Successfully Treated by Endoscopic Stenting

631.00) divided by the mean patent period with PS, PWOS, and EMS were

CLINICAL EVALUATION OF METALLIC STENTING FOR MALIGNANT DUODENAL OBSTRUCTION USING COVERED SELF-EXPANDABLE METALLIC STENT

8.80/d,