MRCP and MRI findings in 9 patients with autoimmune pancreatitis

AIM: To evaluate magnetic resonance cholangiopancre-atography (MRCP) findings in conjunction with magnetic resonance (MR) images in autoimmune pancreatitis (AIP) patients. METHODS: Nine patients with AIP underwent MRI, MRCP, endoscopic retrograde cholangiopancreatography (ERCP), computed tomography, and ultrasonography. The MRCP and MR images taken before and after steroid therapy were reviewed and compared with other imaging modalities. The MRCP findings of the AIP cases were compared to those of 10 cases with carcinoma of the head of the pancreas. RESULTS: On MRCP, the narrowed portion of the main pancreatic duct noted on ERCP was not visualized, while the non-involved segments of the main pancreatic duct were visualized. The degree of upstream dilatation of the proximal main pancreatic duct was milder than that seen in cases of pancreatic carcinoma. Stenosis or obstruction of the lower bile duct was detected in 8 patients. MR images showed enlargement of the pancreas with decreased signal intensity on T1-weighted MR images, increased signal intensity on T2-weighted MR images, and, in 3 patients, a hypointense capsule-like rim. After steroid therapy, the previously not visualized portion of the main pancreatic duct was seen, along with improvement of the bile duct stenosis. Pancreatic enlargement decreased, and the abnormal signal intensity on both T1- and T2-weighted MR images became isointense. CONCLUSION: MRCP cannot differentiate irregular narrowing of the main pancreatic duct seen with AIP from stenosis of the main pancreatic duct seen with pancreatic carcinoma. However, MRCP findings in conjunction with MR imaging of pancreatic enlargement that shows abnormal signal intensity on T1- and T2-weighted MR images are useful in supporting a diagnosis of AIP.     

A case of a “wandering” mobile solitary fibrous tumor occurring in the pancreas

A 73-year-old male with a complaint of abdominal discomfort was examined by abdominal ultrasonography and found to have a hypoechoic mass in the upper abdomen. On abdominal computed tomography (CT), there was a 5-cm, hypervascular mass between the stomach and aorta. Magnetic resonance imaging (MRI) and magnetic resonance cholangiopancreatography (MRCP) showed a homogeneous mass with hypointensity on T1-weighted images, accompanied by stenosis of the main pancreatic duct of the pancreatic head. On endoscopic ultrasonography, the mass was depicted as a round homogeneous, hypervascular mass attached to the pancreatic head. Surprisingly, the mass was located on the right side of the aorta on the second CT. Histological examination of the resected specimen showed that the lesion was composed of spindle cells with cord-like arrangement, the features of which were compatible with a mobile solitary fibrous tumor.     

A case report of pancreatic serous cystadenoma coexistent with adenosquamous carcinoma

A 70-year-old man was admitted to our hospital because a mass was incidentally found in the body of the pancreas. The mass was suspected to be serous cystadenoma from the findings of abdominal enhanced computed tomography, magnetic resonance imaging and endoscopic ultrasonography. In addition, another solid mass was detected in the pancreatic head on imaging tests. Magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography showed stenosis both of the main pancreatic duct at the head and bile duct, but the brushing cytology of the bile duct at ERCP showed no malignant cells. However, the findings of several examinations strongly suggested the coexistence of a serous cystadenoma and a pancreatic cancer, therefore we conducted spleen-preserving total pancreatectomy, and the pathological findings of the resected specimen showed serous cystadenoma coexistence with pancreatic adenosquamous carcinoma.     

Endoscopic retrograde cholangiopancreatography should no longer be used as a diagnostic test: the case in favour

The requirement for diagnostic endoscopic retrograde cholangiopancreatography has decreased considerably in the past 10 years. Alternative imaging techniques are now available for the diagnosis of bile duct stones, pancreatic and biliary tract malignancy and inflammatory diseases such as sclerosing cholangitis and chronic pancreatitis. The imaging techniques include endoscopic ultrasonography, magnetic resonance cholangiopancreatography and helical computed tomography. There is good evidence that these techniques have an accuracy comparable to endoscopic retrograde cholangiopancreatography in the diagnosis of diseases of the bile and pancreatic ducts. All of these methods are less invasive than endoscopic retrograde cholangiopancreatography and have extremely low or negligible complication rates. The choice of technique used depends on local availability and expertise. In future, endoscopic retrograde cholangiopancreatography will be reserved exclusively for therapeutic applications.     

A case of macrocystic serous cystadenoma of the pancreas

Summary A case of macrocystic serous cystadenoma of the pancreas is presented, and literature is reviewed. A 35-yr-old woman presented with mild upper abdominal pain. Abdominal ultrasonography and an abdominal computed tomography revealed a multiloculated and calcified cyst in the body of the pancreas. A T1-weighted image, using magnetic resonance imaging, revealed a low-intensity mutiloculated, pancreatic mass. In contrast, T2-imaging of the tumor showed a high-intensity mass. Endoscopic retrograde cholangiopancreatography showed no contact between the main pancreatic duct and the tumor. The preoperative diagnosis was a mucinous cystic neoplasm. Tumor enucleation was performed. Subsequent microscopic examination of this tumor suggested the diagnosis of a macrocystic serous cystadenoma of the pancreas.     

A rare ring-shaped anomaly of the main pancreatic duct accompanying a branch duct IPMN

The patient was a 74-year-old female. Screening computed tomography for examination of the abdomen showed a cystic mass in the pancreatic body. Close investigation using endoscopic retrograde cholangiopancreatography and magnetic resonance cholangiopancreatography revealed a very rare finding: the main pancreatic duct bifurcated at the pancreatic body, and these two ducts converged at the caudal side. A multilocular cystic mass in the pancreatic body and mucus discharge from the orifice of major papilla were observed. There was no protruded lesion in the main pancreatic duct. No findings suggested apparent malignancy. The patient was diagnosed as having hyperplastic intraductal papillary mucinous neoplasm of branch type showing a ring-shaped pancreatic duct, and was placed under follow-up.     

Diagnostic criteria for pancreaticobiliary maljunction 2013

Pancreaticobiliary maljunction is a congenital malformation in which the pancreatic and bile ducts join anatomically outside the duodenal wall. The diagnostic criteria for pancreaticobiliary maljunction were proposed in 1987. The committee of The Japanese Study Group on Pancreaticobiliary Maljunction (JSGPM) for diagnostic criteria for pancreaticobiliary maljunction began to revise the diagnostic criteria from 2011 taking recently advanced diagnostic imaging techniques into consideration, and the final revised version was approved in the 36^th Annual Meeting of JSPBM. For diagnosis of pancreaticobiliary maljunction, an abnormally long common channel and/or an abnormal union between the pancreatic and bile ducts must be evident on direct cholangiography, such as endoscopic retrograde cholangiopancreatography, percutaneous transpehatic cholangiography, or intraoperative cholangiography; magnetic resonance cholangiopancreatography; or three‐dimensional drip infusion cholangiography computed tomography. However, in cases with a relatively short common channel, it is necessary to confirm that the effect of the papillary sphincter does not extend to the junction by direct cholangiography. Pancreaticobiliary maljunction can be diagnosed also by endoscopic ultrasonography or multi‐planar reconstruction images provided by multi‐detector row computed tomography. Elevated amylase levels in bile and extrahepatic bile duct dilatation strongly suggest the existence of pancreaticobiliary maljunction.     

Magnetic resonance cholangiopancreatography for diagnosing hepatolithiasis

BACKGROUND/AIMS: Direct cholangiography with endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography sometimes fails to adequately opacify the entire biliary tract, because of severe biliary obstruction caused by ductal stricture or lodged stones. We assessed the diagnostic accuracy of magnetic resonance cholangiopancreatography for hepatolithiasis. METHODOLOGY: Five patients with hepatolithiasis underwent ultrasonography, computed tomography, direct cholangiography, and magnetic resonance cholangiopancreatography, using a half-Fourier acquisition single-shot turbo spin-echo sequence. Surgical exploration or pathologic examination revealed stricture and dilatation of the intrahepatic ducts in all patients. Diagnostic accuracies for stones and ductal abnormalities were compared among the imaging studies. RESULTS: No complications occurred during magnetic resonance cholangiopancreatography studies. Magnetic resonance cholangiopancreatography fully depicted the biliary tract. Magnetic resonance cholangiopancreatography accurately detected and localized intrahepatic stones, as well as bile duct stricture and dilatation, in all patients. Intrahepatic stones were detected by endoscopic retrograde cholangiopancreatography in one of four patients and by percutaneous transhepatic cholangiography in all three who underwent this procedure. Endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography demonstrated ductal stricture in all patients but failed to completely demonstrate the biliary tree in three of four patients, and one of three, respectively. On ultrasonography and computed tomography, precise localization of stones was difficult. Ultrasonography and computed tomography failed to demonstrate ductal stricture in one and two of the five patients, respectively. CONCLUSIONS: Magnetic resonance cholangiopancreatography diagnoses intrahepatic stones and bile duct abnormalities less invasively and more accurately than endoscopic retrograde cholangiopancreatography and percutaneous transhepatic cholangiography.     

A case of solid pseudopapillary tumor of the pancreas

INTRODUCTION Most pancreatic tumors are malignant and have a bad prognosis. However, solid-pseudopapillary tumor of the pancreas (SPT) is a rare benign or low-grade malignancy. Because of this, it is important to make the diagnosis of this tumor preoperat…     

Endoscopically inserted endoluminal receiver coil for high-resolution magnetic resonance imaging of the pancreas: Initial results in an animal model

BACKGROUND: This study assessed the feasibility of high-resolution magnetic resonance imaging of the pancreas by means of an endoscopically inserted endoluminal magnetic resonance receiver coil. METHOD: A 0.032-inch diameter internal magnetic resonance imaging receiver coil was endoscopically inserted into the pancreatic duct in 4 pigs through the accessory channel of a standard duodenoscope to obtain high-resolution magnetic resonance images by using T1- and T2-weighted sequences. RESULTS: The pig anatomy precluded the usual transoral approach; however, transgastric access allowed endoscopic transpapillary insertion of a receiver coil into the pancreatic duct in all animals without the need for sphincterotomy. The small swine pancreas could then be visualized by magnetic resonance imaging with a 0.3 x 0.3-mm in-plane resolution. CONCLUSION: High-resolution pancreas magnetic resonance imaging is feasible by using an endoscopically inserted endoluminal receiver coil. The smaller stomach and larger pancreatic duct diameter in humans will facilitate clinical application of the imaging procedure.     

Multicystic biliary hamartoma mimicking intrahepatic cholangiocarcinoma: report of a case

Multicystic biliary hamartoma (MCBH) is a rare cystic disease of the liver. A 69-year-old man was referred to our hospital with radiographic abnormality. Physical examination of the patient was unremarkable, and he denied any previous medical, travel, or surgical history. An abdominal computed tomography (CT) scan demonstrated a 3-cm low-density lesion in segment 3 of the liver, with dilation of the intrahepatic bile duct. The peripheral site of this lesion was slightly enhanced in the arterial phase. In the portal phase, the peripheral site was enhanced more clearly and showed a honeycomb-like dilated bile duct. Ultrasonography also revealed that the lesion was an irregularly shaped mass. On magnetic resonance imaging (MRI), T1-weighted images revealed a low-density mass and T2-weighted images revealed a dappled-density mass with honeycomb-like dilated bile duct and dilation of major intrahepatic bile duct. The patient was diagnosed with intrahepatic cholangiocarcinoma (ICC) and underwent left hepatectomy. However, pathological findings revealed that the lesion was MCBH. Our case highlights the potential difficulties in differentiating between MCBH and ICC under such circumstances.     

Magnetic resonance imaging of cholangiocarcinoma

Cholangiocarcinoma arises from the bile ducts and is the most common primary malignancy of the biliary tree. Cholangiocarcinoma is classified according to its growth pattern: mass-forming, periductal-infiltrating, or intraductal-growing type. The majority of cholangiocarcinomas occur at the common hepatic duct (CHD) and its bifurcation, also referred to as Klatskin's tumor, but they also can occur in more peripheral branches within the hepatic parenchyma. Microscopically, cholangiocarcinoma represents an adenocarcinoma with a glandular appearance arising from the epithelium of the bile ducts. On magnetic resonance (MR) images, cholangiocarcinomas appear hypointense on T1-weighted images, and hyperintense on T2-weighted images. Central hypointensity can be seen on T2-weighted images and correspond to fibrosis. On dynamic MR images, cholangiocarcinomas show moderate peripheral enhancement followed by progressive and concentric filling in the tumor with contrast material. Pooling of contrast within the tumor on delayed MR images is suggestive of peripheral cholangiocarcinoma. The role of MR imaging in hilar cholangiocarcinoma is to confirm/reach a diagnosis and to assess resectability. Hilar cholangiocarcinoma shows the same signal intensity pattern of peripheral tumors both on T1- and T2-weighted images. On magnetic resonance cholangiopancreatography (MRCP) images, hilar cholangiocarcinoma appears as a moderately irregular thickening of the bile duct wall (>/=5 mm) with symmetric upstream dilation of the intrahepatic bile ducts. The aim of preoperative investigation in Klatskin tumors typically requires the evaluation of the level of biliary obstruction, the intrahepatic tumor spread, and the vascular involvement; it also needs to show any atrophy-hypertrophy complex. Because of its intrinsic high tissue contrast and multiplanar capability, MR imaging and MRCP are able to detect and preoperatively assess patients with cholangiocarcinoma, investigating all involved structures such as bile ducts, vessels and hepatic parenchyma. The main reason for surgical/imaging discrepancy is represented by the microscopic diffusion along the mucosa and in the perineural space.     

Biliary reflux detection in anomalous union of the pancreatico-biliary duct patients

AIM: To demonstrate the imaging findings of biliopancreatic and pancreatico-biliary reflux in patients with anomalous union of the pancreatico-biliary duct (AUPBD) on gadoxetic acid-enhanced functional magnetic resonance cholangiography (fMRC).METHODS: This study included six consecutive patients (two men and four women; mean age 47.5 years) with AUPBD. All subjects underwent endoscopic retrograde cholangiopancreatography (ERCP); one subject also underwent bile sampling of the common bile duct (CBD) to measure the amylase level because his gadoxetic acid-enhanced fMRC images showed evidence of pancreatico-biliary reflux of pancreatic secretions. Of the five patients with choledochal cysts, four underwent pylorus-preserving pancreaticoduodenectomy.RESULTS: The five cases of choledochal cysts were classified as Todani classification I. In three of the six patients with AUPBD, injected contrast media reached the distal CBD and pancreatic duct on delay images, suggesting biliopancreatic reflux. In two of these six patients, a band-like filling defect was noted in the CBD on pre-fatty meal images, which decreased in size on delayed post-fatty meal images, suggesting pancreatico-biliary reflux of pancreatic secretions, and the bile sampled from the CBD in one patient had an amylase level of 113 000 IU/L. In one of the six patients with AUPBD, contrast media did not reach the distal CBD due to multiple CBD stones.CONCLUSION: Gadoxetic acid-enhanced fMRC successfully demonstrated biliopancreatic reflux of bile and pancreatico-biliary reflux of pancreatic secretions in patients with AUPBD with and without choledochal cysts.     

Detection of choledocholithiasis: comparison of unenhanced spiral CT, US, and ERCP

BACKGROUND/AIMS: ERCP is an established method for the diagnosis and treatment of common bile duct stones, however, it is invasive, time-consuming, and expensive. The purpose of this study was to determine whether unenhanced spiral CT and US, compared with ERCP, have sufficient sensitivity and negative predictive value to be useful screening techniques in patients suspected of having choledocholithiasis. METHODOLOGY: Over a period of 2 years, 82 patients with clinically suspected choledocholithiasis underwent unenhanced spiral computed tomography and US immediately before undergoing endoscopic retrograde cholangiopancreatography. CT/US scans and ERCP images were evaluated for the presence of bile duct stones, ampullary stones, and extrahepatic biliary dilatation. RESULTS: Unenhanced spiral computed tomography (US) depicted common bile duct stones in 24 (23) of 28 patients found to have stones at endoscopic retrograde cholangiopancreatography. Five patients had stones impacted at the ampulla, all (two) of which were detected with CT (US). Computed tomography (US) had a sensitivity of 86% (82%) and a specificity of 98% (98%) in the diagnosis of choledocholithiasis. CONCLUSIONS: Both unenhanced spiral CT and US are useful for evaluating suspected common bile duct stones. Unenhanced spiral CT is especially useful when the patient is likely to have ampullary stones and is a safe, more available and less expensive alternative to magnetic resonance cholangiography.     

ENDOSCOPIC OBSERVATION OF MUCOSAL SPREAD LESION OF CHOLANGIOCARCINOMA USING PERORAL CHOLANGIOSCOPY WITH NARROW BAND IMAGING

A 69‐year‐old man was admitted to Toho University Omori Medical Center complaining of icterus. Abdominal computed tomography, magnetic resonance cholangiopancreatography and endoscopic retrograde cholangiopancreatography were suspicious of cholangioma of inferior bile duct. Peroral cholangioscopy using narrow band imaging (NBI) was performed and it was possible to diagnose the mucosal spread lesions of cholangioma. Histological findings reflected the endoscopic findings. Mucosal spread lesions of cholangiocarcinoma were successfully diagnosed using the CHF‐B260 for NBI.     

Schwannoma in the hepatoduodenal ligament: A case report and literature review

Schwannomas are mesenchymal neoplasms with low malignant potential that arise from Schwann cells. They can occur almost anywhere, although the most common locations are the head, neck and extremities. Primary benign schwannoma of the hepatoduodenal ligament is rare. To date, only three cases have been reported in the English literature. In the present study, we report a case of hepatoduodenal ligament schwannoma in a 43-year-old male, who was admitted to our hospital because of a abdominal mass found by physical examination. It was hard to determine the definitive location and diagnosis of the mass using ultrasound, computed tomography and magnetic resonance cholangiopancreatography. During laparotomy, the mass was found in the hepatoduodenal ligament and close to the cholecystic duct, so we resected the gallbladder and cholecystic duct along with the mass. The gross specimen revealed an 8.5 cm × 5.5 cm × 3.0 cm localized tumor. Microscopic examination showed that the tumor was mainly composed of spindle-shaped cells. Immunohistochemical staining showed a strong positive S-100 protein reaction. Finally, the lesion was diagnosed as a benign schwannoma in the hepatoduodenal ligament. However, one month later, the patient was readmitted to our hospital because of skin and sclera jaundice caused by common bile duct stenosis without common bile duct stone or tumor. The patient recovered well after implantation of a common bile duct stent under endoscopic retrograde cholangiopancreatography. He was followed up for a period of 17 mo, during which he was well with no complications.     

Biliary stones and stenoses: diagnostic value of magnetic resonance cholangiography.

BACKGROUND/AIMS: To evaluate the accuracy of magnetic resonance cholangiography for detection of bile duct calculi and stenosis. METHODS: Half-Fourier single-shot rapid acquisition with relaxation enhancement sequence magnetic resonance cholangiography was performed prospectively in 68 patients who were suspected of having choledocholithiasis or biliary tree stenosis. On the basis of findings at ultrasound, computed tomography, endoscopic retrograde or percutaneous cholangiography, intraoperative cholangiography or choledocoscopy and exploration, final diagnoses were normal bile ducts (n=8), choledocholithiasis (n=28), benign or malignant stenosis (n=32). RESULTS: Choledocholithiasis was diagnosed with a sensitivity of 96% and a specificity of 98%. False negative readings occurred due to stones less than two mm at in size at the distal common bile duct. A false diagnosis of choledocholithiasis (single impacted stone) by magnetic resonance cholangiography occurred in only one case for whom the final diagnosis was main bile duct adenocarcinoma, suspected on endoscopic retrograde cholangiography and confirmed at surgery. Bile duct stenosis was diagnosed with a sensitivity of 97% and a specificity of 94%. CONCLUSIONS: With magnetic resonance cholangiography, bile duct calculi and stenosis can be diagnosed with high accuracy. It is a fast, accurate and noninvasive alternative to endoscopic retrograde cholangiography in the evaluation of biliary tract disease.     

Poorly vascularized malignant insulinoma displaced the pancreatic ducts around the mass on endoscopic retrograde cholangiopancreatography

A 66-year-old woman with an altered mental status caused by hypoglycemia was referred to Akita City Hospital. Abdominal ultrasonography (US) and endoscopic US revealed an isoechoic mass measuring 25 mm in the head of the pancreas. Endoscopic retrograde cholangiopancreatography (ERCP) revealed that the main pancreatic duct and its branches were displaced around the mass in the head of the pancreas. On arteriography, a poorly vascularized tumor was observed. Dynamic contrast-enhanced computed tomography (CT) showed a low-attenuation mass in the head of the pancreas. A pylorus-preserving pancreaticoduodenectomy was performed. Microscopically, the diagnosis was malignant insulinoma.     

CT and MR Imaging Findings of Pancreatic Paragangliomas: A Case Report

Previous studies on pancreatic paraganglioma, a rare neoplasm, have primarily reported its ultrasound and routine and contrast-enhanced computed tomography (CT) findings. To our knowledge, we are the first to report the contrast-enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) sequence findings of pancreatic paraganglioma.A male patient, ages 41 years, was admitted to our hospital due to a pancreatic space-occupying lesion that had been present for more than 10 days. The patient had no obvious discomfort. He had a history of hypertension and hyperthyroidism. Physical examination revealed upper abdominal tenderness without a palpable mass. Routine and contrast-enhanced abdominal CT showed a soft tissue mass at the pancreatic head/uncinate process, with patchy calcification within the lesion. On a contrast-enhanced CT scan, severe enhancement of the mass in the arterial phase was noted, as was slightly reduced but still marked enhancement in the venous phase. The celiac trunk and superior mesenteric artery segment were wrapped by the tumor. Thickened, tortuous vessels were observed at the lesion edges, around which there were multiple enlarged lymph nodes. The main pancreatic duct was markedly dilated. Routine and contrast-enhanced pancreatic MRI demonstrated an abnormal nodular signal in the pancreatic head/uncinate process that was approximately 4.3 × 6.4 cm² in size. T1-weighted imaging (T1WI) revealed hypointensity, whereas T2-weighted imaging (T2WI) revealed nonhomogeneous, slight hyperintensity. Patchy hypointensity on both T1WI and T2WI was observed within the lesion. DWI showed slight hyperintensity. Grossly heterogeneous enhancement of the mass was observed on a contrast-enhanced MRI scan, with the tumor wrapped around the adjacent vasculature, and multiple enlarged lymph nodes were observed peripherally. After preoperative preparation, the patient underwent pancreatoduodenectomy. Histopathology and immunohistochemistry of the resected tumor indicated pancreatic paraganglioma. After surgery, the patient recovered well, without presenting any recurrence or metastasis during short-term follow-up.For hypervascular pancreatic tumors on contrast-enhanced CT or MRI, and particularly those occurring in the pancreatic head, with a clear display of draining veins, the possibility of pancreatic paraganglioma should be considered. These tumors usually exhibit necrosis or cystic changes and are occasionally accompanied by calcification.     

Autoimmune pancreatitis associated with a large pancreatic pseudocyst that disappeared after corticosteroid therapy: a case report and literature review

A 51-year-old woman was admitted to our department because of upper abdominal pain. The serum IgG4 concentration was elevated, and abdominal computed tomography revealed diffuse enlargement of the pancreas associated with a large cyst, measuring 8 cm in diameter. Endoscopic retrograde cholangiopancreatography revealed narrowing of the main pancreatic duct (from the body to the tail), narrowing of the intrapancreatic bile duct, and dilatation of the bile ducts. The patient was given a diagnosis of autoimmune pancreatitis (AIP) associated with a pancreatic pseudocyst and intrapancreatic bile duct stenosis. Oral steroid therapy resulted in reduced pancreatic swelling, complete disappearance of the pancreatic cyst, and an improvement in biliary stenosis. AIP is rarely associated with pancreatic cyst, and only 13 cases, including ours, have been reported to date. In our patient, intense inflammation apparently led to cyst formation in association with AIP, which responded remarkably to corticosteroid therapy. Correct diagnosis of AIP associated with a pancreatic pseudocyst might save patients from undergoing unnecessary endoscopic and surgical procedures.