Xanthogranulomatous cholecystitis mimicking gallbladder carcinoma with a false-positive result on fluorodeoxyglucose PET

Recently, several reports have demonstrated that fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is useful in differentiating between benign and malignant lesions in the gallbladder. However, there is a limitation in the ability of FDG-PET to differentiate between inflammatory and malignant lesions. We herein present a case of xanthogranulomatous cholecystitis misdiagnosed as gallbladder carcinoma by ultrasonography and computed tomography. FDG-PET also showed increased activity. In this case, FDG-PET findings resulted in a false-positive for the diagnosis of gallbladder carcinoma.Recently, several reports have demonstrated that fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) is useful in differentiating between benign and malignant lesions in the gallbladder. However, there is a limitation in the ability of FDG-PET to differentiate between inflammatory and malignant lesions. We herein present a case of xanthogranulomatous cholecystitis misdiagnosed as gallbladder carcinoma by ultrasonography and computed tomography. FDG-PET also showed increased activity. In this case, FDG-PET findings resulted in a false-positive for the diagnosis of gallbladder carcinoma.

Clinical and radiological feature of lymphoepithelial cyst of the pancreas

A lymphoepithelial cyst(LEC)of the pancreas is a rare benign lesion.Because patients with LEC of the pancreas have a good prognosis,it is important that these lesions are accurately differentiated from other more aggressive pancreatic neoplasms for an appropriate treatment strategy.Previous studies have reported that a definitive diagnosis of LEC often cannot be obtained based solely on the findings of preoperative imaging(e.g.,Computed tomography or Magnetic resonance imaging).In this study,we reviewed four cases of pancreatic LECs to investigate the feature of LECs.We reviewed these cases with regard to symptoms,imaging findings,surgical procedures,and other clinical factors.We found that LEC was associated with unique characteristics on imaging findings.A preoperative diagnosisof LEC may be possible by comprehensively evaluating its clinical and imaging findings.

Isolated intrapancreatic Ig G4-related sclerosing cholangitis

Immunoglobulin G4-related sclerosing cholangitis(Ig G4-SC) is frequently associated with type 1 autoimmune pancreatitis(AIP). Association with AIP can be utilized in the diagnosis of Ig G4-SC. However, some cases of Ig G4-SC are isolated from AIP, which complicates the diagnosis. Most of the reported cases of isolated Ig G4-SC displayed hilar biliary strictures, whereas isolated Ig G4-SC with intrapancreatic biliary stricture is very rare. Recently, we have encountered 5 isolated intrapancreatic Ig G4-SC cases that were not associated with AIP, three of which were pathologically investigated after surgical operation. They all were males with a mean age of 74.2 years. The pancreas was not enlarged in any of these cases. No irregular narrowing of the main pancreatic duct was found. Bile duct wall thickening in lesions without luminal stenosis was detected by abdominal computed tomography in all five cases, by endoscopic ultrasonography in two out of four cases and by intraductal ultrasonography in all three cases. In three cases, serum Ig G4 levels were within the normal limits. The mean serum Ig G4 level measured before surgery was 202.1 mg/d L(4 cases). Isolated intrapancreatic Ig G4-SC is difficult to diagnose, especially if the Ig G4 level remains normal. Thus, this type of Ig G4-SC should be suspected in addition to cholangiocarcinoma and pancreatic cancer if stenosis of intrapancreatic bile duct is present.

Intraductal papillary neoplasm of the bile duct accompanying biliary mixed adenoneuroendocrine carcinoma

We present the first case of an intraductal papillary neoplasm of the bile duct(IPNB) accompanying a mixed adenoneuroendocrine carcinoma(MANEC).A 74-yearold woman presented with fever of unknown cause.Laboratory data revealed jaundice and liver injury.Contrast-enhanced computed tomography revealed a 20 mm polypoid tumor in the dilated distal bile duct,which exhibited early enhancement and papillary growth.Upper gastrointestinal endoscopy revealed mucus production from the papilla of Vater,characterized by its protruding and dilated orifice.Endoscopic ultrasonography visualized the polypoid tumor in the distal bile duct,but no invasive region was suggested by diagnostic imaging.Therefore,the initial diagnosis was IPNB.After endoscopic nasobiliary drainage,a pylorus-preserving pancreaticoduodenectomy was performed.Pathological examination of the resected bile duct revealed papillary proliferation of biliary-type cells with nuclear atypia,indicating pancreaticobiliary-type IPNB.In addition,solid portions comprised of tumor cells with characteristic salt-and-pepper nuclei were evident.Immunohistochemistry revealed expression of the neuroendocrine marker synaptophysin in this solid component,diagnosing it as a neuroendocrine tumor(NET).Furthermore,the MIB-1 proliferation index of NET was higher than that of IPNB,and microinvasion of the NET component was found,indicating neuroendocrine carcinoma(NET G3).This unique case of MANEC,comprising IPNB and NET,provides insight into the pathogenesis of biliary NET.

A case report of anaplastic carcinoma of the pancreas with remarkable intraductal tumor growth into the main pancreatic duct

We herein report a case of anaplastic carcinoma of the pancreas with remarkable intraductal tumor growth into the main pancreatic duct.A 76-year-old male was referred to our hospital for treatment of a pancreatic tumor.Preoperative examinations revealed a poorly defined tumor in the main pancreatic duct in the body of the pancreas,accompanied with severe dilatation of the main pancreatic duct,which was diagnosed as an intraductal papillary-mucinous neoplasm.We performed distal pancreatectomy and splenectomy.The pathological examination revealed that the tumor consisted of a mixture of anaplastic carcinoma(giant cell type)and adenocarcinoma in the pancreas.There was a papillary projecting tumor composed of anaplastic carcinoma in the dilated main pancreatic duct.The patient is now receiving chemotherapy because liver metastasis was detected 12 mo after surgery.In this case,we could observe a remarkable intraductal tumor growth into the main pancreatic duct.We also discuss the pathogenesis and characteristics of this rare tumor with specific tumor growth.