Biliary Duct Dilatation: AJR Expert Panel Narrative Review

Biliary duct dilatation is a common incidental finding in practice, but it is unlikely to indicate biliary obstruction in the absence of clinical symptoms or elevated levels on liver function tests (LFTs). However, the clinical presentation may be nonspecific, and LFTs may either be unavailable or difficult to interpret. The goal of this AJR Expert Panel Narrative Review is to highlight a series of topics fundamental to the management of biliary duct dilatation, providing consensus recommendations in a question-and-answer format. We start by covering a basic approach to interpreting LFT results, the strengths and weaknesses of the biliary imaging modalities, and how and where to measure the extrahepatic bile duct. Next, we define the criteria for biliary duct dilatation, including patients with prior cholecystectomy and advanced age, and discuss when and whether biliary duct dilatation can be attributed to papillary stenosis or sphincter of Oddi dysfunction. Subsequently, we discuss two conditions in which the duct is pathologically dilated but not obstructed: congenital cystic dilatation (i.e., choledochal cyst) and intraductal papillary neoplasm of the bile duct. Finally, we provide guidance regarding when to recommend obtaining additional imaging or testing, such as endoscopic ultrasound or ERCP, and include a discussion of future directions in biliary imaging.

Differentiation of malignant from benign ampullary strictures: A prediction nomogram based on MR imaging and clinical findings

PURPOSE

To construct a predictive nomogram based on contrast-enhanced magnetic resonance imaging (MRI) and clinical findings for differentiating malignant from benign ampullary strictures.

METHOD

In this retrospective study, 76 patients with ampullary strictures (51 benign and 25 malignant) who underwent contrast-enhanced MRI were enrolled. Imaging findings were evaluated independently by two abdominal radiologists who reached consensus. Clinical findings were also collected. Significant findings for malignant ampullary strictures were assessed by univariable and multivariable logistic regression analyses. Based on the results of multivariable analysis, a nomogram to differentiate malignant from benign ampullary strictures was developed and internally validated.

RESULTS

In multivariable analysis, presence of an ampullary mass (odds ratio [OR]: 8.42, p = 0.047), bulging ampulla (OR: 8.32, p = 0.033), diffusion restriction of the ampulla (OR: 42.76, p = 0.004) on MRI, and jaundice (OR: 12.41, p = 0.019) were significant predictors of malignant ampullary strictures. A predictive nomogram was constructed using these findings. Among them, diffusion restriction of the ampulla showed the highest OR and predictor score on the nomogram. The calibration plots for internal validation achieved strong agreement between the predicted probabilities and the actual rates of malignant ampullary strictures.

CONCLUSION

A combination of significant contrast-enhanced MRI and clinical findings of ampullary mass, bulging ampulla, diffusion restriction of the ampulla, and jaundice may be useful in the prediction of malignant ampullary stricture.

Development and Validation of Prognostic Nomograms for Periampullary Neuroendocrine Neoplasms: A SEER Database Analysis

(1) Background: Periampullary neuroendocrine neoplasms (NENs) are rare tumors that lack a prognostic prediction model. We aimed to design comprehensive and effective nomograms to predict prognosis; (2) Methods: Univariate and multivariate Cox analyses were used to screen out significant variables for the construction of the nomograms. The discrimination and calibration of the nomograms were carried out using calibration plots, concordance indices (C-indices), and area under time-dependent receiver operating characteristic curves (time-dependent AUCs). Decision curve analysis (DCA) was used to compare the clinical applicability of the nomograms, TNM (Tumor- Node-Metastasis) stage, and SEER stage; (3) Results: The independent risk factors for overall survival (OS) and cancer-specific survival (CSS) of patients with periampullary NENs included age, tumor size, histology, differentiation, N stage, M stage, and surgery, which were used to construct the nomograms. The calibration curves and C-indices showed a high degree of agreement between the predicted and actual observed survival rates. The AUCs displayed good calibration and acceptable discrimination of the nomograms. Additionally, the DCA curves indicated that the nomograms showed better clinical applicability; (4) Conclusions: We developed and validated nomogram prognostic models for patients with periampullary NENs. The nomograms provided insightful and applicable tools to evaluate prognosis.

Differentiating between benign and malignant ampullary strictures: a prediction model using a nomogram based on CT imaging and clinical findings

OBJECTIVES

To construct a predictive nomogram for differentiating malignant from benign ampullary strictures using contrast-enhanced computed tomography (CT) findings combined with clinical findings.

METHODS

In this retrospective study, 152 patients with ampullary stricture (98 benign and 54 malignant) who underwent contrast-enhanced CT were included. Various imaging findings of the ampulla, bile duct, main pancreatic duct, and periampullary area were evaluated and clinical findings including the presence of jaundice, carbohydrate antigen 19-9 level, and history of cholecystectomy were collected. Among them, statistically significant findings were identified using univariable and multivariable logistic regression analyses. A nomogram was constructed to differentiate benign and malignant ampullary strictures and was internally validated.

RESULTS

Multivariable analysis revealed that jaundice (odds ratio [OR]: 17.33, p < 0.001), presence of an ampullary mass (OR: 24.40, p < 0.001), non-similar enhancement of the ampulla to the duodenum (OR: 31.96, p = 0.003), and proportional dilatation of the bile duct (OR: 7.98, p = 0.001) were independent significant factors for predicting the malignant ampullary stricture, and were used to construct a nomogram. Among them, non-similar enhancement of the ampulla to the duodenum showed the highest OR and predictor point on the nomogram. The calibration plots showed excellent agreement between the predicted probabilities and the actual rates of malignant ampullary strictures, on internal validation.

CONCLUSIONS

Combination of clinical and imaging findings could aid in predicting malignant ampullary strictures using significant findings of jaundice, presence of ampullary mass, non-similar enhancement of the ampulla to the duodenum, and proportional dilatation of the bile duct.

KEY POINTS

• The presence of jaundice, ampullary mass, non-similar enhancement of the ampulla, and proportional bile duct dilatation were significant findings for predicting malignant ampullary strictures. • Non-similar enhancement of the ampulla to the duodenum was a significant feature with the highest odds ratio for differentiating benign and malignant ampullary strictures. • The nomogram constructed using contrast-enhanced computed tomography imaging and clinical findings could aid in predicting malignant ampullary strictures.

Imaging Features of Premalignant Biliary Lesions and Predisposing Conditions with Pathologic Correlation

Biliary malignancies include those arising from the intrahepatic and extrahepatic bile ducts as well as the gallbladder and hepatopancreatic ampulla of Vater. The majority of intrahepatic and extrahepatic malignancies are cholangiocarcinomas (CCAs). They arise owing to a complex interplay between the patient-specific genetic background and multiple risk factors and may occur in the liver (intrahepatic CCA), hilum (perihilar CCA), or extrahepatic bile ducts (distal CCA). Biliary-type adenocarcinoma constitutes the most common histologic type of ampullary and gallbladder malignancies. Its prognosis is poor and surgical resection is considered curative, so early detection is key, with multimodality imaging playing a central role in making the diagnosis. There are several risk factors for biliary malignancy as well as predisposing conditions that increase the risk; this review highlights the pertinent imaging features of these entities with histopathologic correlation. The predisposing factors are broken down into three major categories: (a) congenital malformations such as choledochal cyst and pancreaticobiliary maljunction; (b) infectious or inflammatory conditions such as parasitic infections, hepatolithiasis, primary sclerosing cholangitis, and porcelain gallbladder; and (c) preinvasive epithelial neoplasms such as biliary intraepithelial neoplasm, intraductal papillary neoplasm of the bile duct, intra-ampullary papillary tubular neoplasm, and intracholecystic papillary neoplasm of the gallbladder. Recognizing the baseline features of these premalignant biliary entities and changes in their appearance over time that indicate the advent of malignancy in high-risk patients can lead to early diagnosis and potentially curative management. An invited commentary by Volpacchio is available online. Online supplemental material is available for this article. ^©RSNA, 2022.

Validity of MDCT cholangiography in differentiating benign and malignant biliary obstruction

Background

MDCT cholangiography can be utilized to identify variant biliary anatomy to guide preoperative planning of biliary surgery, and determine the cause and level of biliary obstruction. Early tumor detection and staging of biliary cancer are key factors for a possible cure by surgical resection. Between December 2019 and October 2020, 69 patients with clinically suspected biliary obstruction were enrolled in the study, subjected to clinical assessment (full history taking and clinical examination) and imaging assessment by MDCT cholangiography. Our findings were correlated to standard reference examinations including operative/ERCP/biopsy and histopathology findings.

Results

The most affected age was between 60 and 70 years old, and males were more affected. The commonest clinical presentation was yellowish discoloration of the skin and sclera followed by biliary colic. Right hypochondrial tenderness was the main clinical finding on clinical examination. Our patients were categorized according to the etiology of biliary obstruction into 7 groups: malignant stricture 52.2% (36 patients), calcular 24.6% (17 patients), iatrogenic 5.8% (4 patients), portahepatis lesions 5.8% (4 patients), benign stricture 4.3% (3 patients), inflammatory 4.3% (3 patients), and congenital 1.4% (1 patient). The malignant group shows dominant mass, moderate biliary obstruction, and arterial and venous enhancement. The overall sensitivity was 94% for malignancy.

Conclusion

MDCT cholangiography is non-invasive, fast, and highly sensitive and specific in the diagnosis of different causes and levels of biliary obstruction and is useful in the characterization of the lesion in cases of malignant obstruction and differentiating it from benign stricture. It can be used as an effective alternative to ERCP or PTC.

Imaging of Ampullary and Periampullary Conditions

The ampulla of Vater is formed by the union of the pancreatic duct and the common bile duct and is also known as hepatopancreatic ampulla or hepatopancreatic duct. The ampulla is surrounded by a muscular valve known as the sphincter of Oddi, which controls the flow of bile and pancreatic juices into the duodenum in response to food. The ampulla is also an important embryological landmark as it marks the anatomical transition from foregut to the midgut. Because of this, it is a watershed zone where the blood supply changes from the celiac axis to the superior mesenteric artery. Radiologic evaluation of the ampulla and the periampullary region is challenging because it requires an understanding of the embryology, the normal appearance, and different anatomic variants. Also, a wide variety of pathologies can occur in this region. The purpose of this review is to present the normal anatomy of the ampulla and the periampullary region on different imaging modalities and to summarize the imaging features of the common variants, and benign and malignant ampullary and periampullary conditions. Understanding of the normal anatomical appearance and variants along with the knowledge of common pathologic conditions affecting the ampulla and periampullary conditions can help radiologists in making accurate diagnosis resulting in optimum patient care.

Adenomatous neoplasia in the papilla of Vater endoscopic and/or surgical resection?

BACKGROUND

Adenomatous neoplasia in the papilla of Vater needs to be resected in order not to progress. It can be challenging to distinguish between early ampullary malignant lesions and non-invasive adenomas, due to the overlap in symptoms and radiological findings. This retrospective study describes the different findings and treatment decisions taken prior to endoscopic and/or surgical resection of ampullary adenomatous lesions.

MATERIALS AND METHODS

Patients treated with endoscopic and/or surgical resection for suspected or verified ampullary adenomatous neoplasia, between January 2006 and July 2018, where pre-interventional cross-sectional imaging could not discern an obvious invasive, malignant tumor, were included. Findings were compared against the final diagnosis of the histopathological analysis on the resected specimen.

RESULTS

In total, 172 met the inclusion criteria. Patients were treated with either surgical resection (n = 96), endoscopic papillectomy (EP) (n = 55) or both (n = 21). The final diagnosis was in 48% ampullary adenocarcinoma, and the remaining had either ampullary adenoma (38%) or non-neoplastic lesions (14%). In patients where symptoms and cross-sectional imaging were suspicious for malignancy, but with no tissue samples that confirmed neoplasia prior to surgical resection, only 47% had adenocarcinoma. The remaining had either adenoma (9%) or non-neoplastic lesions (44%). Adenocarcinoma was revealed in 27% of the patients where endoscopic biopsies had shown adenoma. Patients with adenoma, treated with EP, were cured in 59%. However, 28% were after EP sent for further surgery due to ductal invasion or a finding of adenocarcinoma.

CONCLUSIONS

In patients with a suspicion of ampullary neoplasia on imaging, attempts should be made to get endoscopic tissue samples before deciding on a treatment strategy. If biopsies show ampullary adenoma, patients should be considered for EP, unless there are clear radiologic or endoscopic signs of malignancy. Patients with adenocarcinoma on endoscopic biopsies should undergo surgical resection.

Radiographic Features and Clinical Factor for Preoperative Prediction in the Bulging Duodenal Papilla With Malignancy

Background

To investigate characteristic clinical and imaging features and establish a scoring system for preoperative prediction of malignancy in the bulging duodenal papilla.

Methods

A total of 147 patients with bulging duodenal papilla (Benign enlargement n = 67; malignant enlargement n = 80) from our hospital between 2010 and 2020 were retrospectively analyzed. We investigated meaningful clinical and CT imaging features and established the score model through logistic regression and weighted. The calibration test, the ROC, AUC, and cut-off points were performed in score model. The model was also divided into three score ranges for convenient clinical evaluation.

Results

Three clinical and CT imaging features were finally included in the score model including direct bilirubin (DBil) increase >7 umol/L (3 points), pancreatic duct (PD) dilation >5 mm (2 points), and irregular shape (2 points). The AUCs of the primary predictive model and score model were 0.896 (95% CI, 0.835-0.940) and 0.896 (95% CI, 0.835-0.940), respectively. This scoring system presented with a sensitivity of 78.8% and a specificity of 88.1% when using 2.5 points as cutoff value. Three score ranges were also proposed for convenient clinical use as follows: 0-2 points; 3-4 points; 5-7 points. The number of patients with malignant duodenal papillary enlargement increased with the increasing scores.

Conclusions

We proposed a convenient scoring system to preoperative predict malignancy in the bulging duodenal papilla.

A rolling stone: vomiting of a gallstone without the presence of a biliary-enteric fistula

Gallstones may pass into the gastrointestinal tract spontaneously through the ampulla of Vater or through a biliary-enteric fistula. This report describes an extremely rare case of a patient vomiting a gallstone without the presence of a fistula between the gallbladder and the gastrointestinal tract. Furthermore, no imaging findings of gallstones disease appeared. The patient has been treated conservatively and all symptoms subsided. The patient remains asymptomatic 3 months after treatment and an elective laparoscopic cholecystectomy was arranged. Including this reported case, only three cases have been described in the literature worldwide. However, our case is the only one characterized by retrograde flow of the gallstones into the stomach without symptoms of bowel obstruction or other underlying pathologies.

Periampullary duodenal schwannoma mimicking ampullary neoplasm

Schwannomas are neurogenic tumors that arise from Schwann cells in the neural sheath. Gastrointestinal schwannomas occur most often in the stomach, followed by the colon and the rectum. Duodenal schwannomas are rare amongst mesenchymal tumors of the gastrointestinal tract and only a few cases have been reported up to the current date with an incidence of approximately 2%-6%. Duodenal Schwannomas do not have characteristic imaging features thereby cannot be easily differentiated from other submucosal and adjacent extraluminal neoplasms. We present a case of a 76-year old male patient that presented to our hospital with abdominal pain and was diagnosed after an upper gastrointestinal endoscopy with an ampullary duodenal neoplasm that proved to be a periampullary duodenal Schwannoma on histopathology. Duodenal Schwannomas although rare should be considered in the differential diagnosis of ampullary neoplasms.

Exosomal miRNA signatures of pancreatic lesions

BACKGROUND

Pancreatic and peri-pancreatic neoplasms encompass a variety of histotypes characterized by a heterogeneous prognostic impact. miRNAs are considered efficient candidate biomarkers due to their high stability in tissues and body fluids. We applied Nanostring profiling of circulating exosomal miRNAs to distinct pancreatic lesions in order to establish a source for biomarker development.

METHODS

A series of 140 plasma samples obtained from patients affected by pancreatic ductal adenocarcinoma (PDAC, n = 58), pancreatic neuroendocrine tumors (PanNET, n = 42), intraductal papillary mucinous neoplasms (IPMN, n = 20), and ampulla of Vater carcinomas (AVC, n = 20) were analyzed. Comprehensive miRNA profiling was performed on plasma-derived exosomes. Relevant miRNAs were validated by qRT-PCR and in situ hybridization (ISH).

RESULTS

Lesion specific miRNAs were identified through multiple disease comparisons. Selected miRNAs were validated in the plasma by qRT-PCR and at tissue level by ISH. We leveraged the presence of clinical subtypes with each disease cohort to identify miRNAs that are differentially enriched in aggressive phenotypes.

CONCLUSIONS

This study shows that pancreatic lesions are characterized by specific exosomal-miRNA signatures. We also provide the basis for further explorations in order to better understand the relevance of these signatures in pancreatic neoplasms.

Combination of CEUS and MRI for the diagnosis of periampullary space-occupying lesions: a retrospective analysis

Background

The value of magnetic resonance imaging (MRI), contrast-enhanced ultrasound (CEUS), and the combination of CEUS and MRI (CCWM) for the diagnosis of periampullary space-occupying lesions (PSOL) was investigated.

Methods

A total of 102 patients diagnosed with PSOLs by surgery or biopsy were recruited retrospectively. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of MRI, CEUS, and CCWM were analyzed.

Results

MRI, CEUS, and CCWM allowed for the accurate detection of 91.17, 92.15, and 99.01% of PSOLs, respectively. The specificity, PPV, and accuracy of CCWM were significantly different from MRI and CEUS (p < 0.05). However, there the sensitivity and NPV were not significantly different among the three diagnostic technologies. In addition, the specificity, PPV, and accuracy were not significantly different between MRI and CEUS (all p > 0.05).

Conclusions

CCWM is valuable for differentiating benign and malignant PSOL, which provides important guiding significances for the clinic.

MRI evaluation of pancreatic ductal adenocarcinoma: diagnosis, mimics, and staging

The radiologist's role in the evaluation of pancreatic ductal adenocarcinoma remains critical in the management of this deadly disease. Imaging plays a vital role in the diagnosis and staging of pancreatic cancer. Although CT is more commonly used for staging pancreatic cancer, MR is increasingly playing an important role in this regard. In our institution, all pancreatic malignancies undergo staging with MRI. In this pictoral essay, we illustrate the MR imaging features of pancreatic ductal adenocarcinoma and its mimics, and we also discuss pearls and pitfalls in MR staging of pancreatic carcinoma.

[Diagnosis and surgical treatment of duodenal tumors]

AIM

To present the experience in diagnosis and surgical treatment of duodenal tumors.

MATERIAL AND METHODS

The study included 27 patients with different duodenal tumors: adenocarcinoma (AC, n=8), gastrointestinal stromal tumor (GIST, n=13), neuroendocrine tumor (NET, n=6). The examination included computed tomography (in 27 patients), magnetic resonance imaging (12), transcutaneous ultrasound (14), endosonography (16), esophagogastroduodenoscopy (16). All patients were operated. Conventional (18), laparoscopic (4), robot-assisted (4), endoscopic endoluminal (1) surgical interventions were performed. 17 patients were followed up from 8 months to 10 years (median 26 months).

RESULTS

According to the instrumental diagnostic methods, duodenal tumors were verified in 19 cases. Five patients with AC underwent pancreaticoduodenectomy (Whipple procedure), 2 - palliative operations (bypass gastroenteroanastomosis), 1 - explorative laparotomy. Patients with GIST underwent 3 pancreaticoduodenectomies and 10 duodenectomies: traditional (4), laparoscopic (4) and robot-assisted (2) approaches. In case of NET 3 interventions via traditional approach (pancreaticoduodenectomy, duodenal resection, tumor enucleation), 1 endoscopic endoluminal operation, 2 robot-assisted operations (duodenal resection and duodenopancreatectomy, splenectomy, distal gastrectomy) were performed. Postoperative complications occurred in 10 (37%) patients. Postoperative mortality was absent. Long-term results were analyzed in 17 patients. All patients with GIST and NET are alive without disease progression. Two AC patients are alive from those who are available.

CONCLUSION

Duodenal tumors are relatively rare. Radical surgical intervention in accordance with oncological principles is preferred for these patients. Organ-preserving procedures may be applied depending on morphological type of tumor. Examination and treatment of patients with duodenal tumors should be carried out in specialized surgical departments.

Present status and perspectives of endosonography 2017 in gastroenterology

Endoscopic ultrasound has become an essential tool in modern gastroenterology and abdominal surgery. Compared with all other endoscopic methods, it has the most potential for innovation and its future looks bright. Thus, we compiled this summary of established and novel applications of endoscopic ultrasound methods to inform the reader about what is already possible and where future developments will lead in improving patient care further. This review is structured in four parts. The first section reports on developments in diagnostic endoscopic ultrasound, the second looks at semi-invasive endoscopic ultrasound, and the third discusses advances in therapeutic endoscopic ultrasound. An overview on the future prospects of endoscopic ultrasound methods concludes this article.

Paraduodenal pancreatitis: benign and malignant mimics at MRI

Paraduodenal pancreatitis, also known as groove pancreatitis, is a rare form of chronic pancreatitis that masquerades as pancreatic adenocarcinoma affecting the pancreaticoduodenal groove, a potential space between the head of the pancreas, duodenum, and common bile duct. Two forms of groove pancreatitis have been described. The segmental form involves the pancreatic head with development of scar tissue within the groove, whereas the pure form affects the groove only, sparing the pancreatic head. Imaging findings of groove pancreatitis often overlap with primary duodenal, ampullary, or pancreatic neoplasms, which often results in a diagnostic challenge. In addition, paraduodenal pancreatitis can be mistaken for cystic pancreatic lesions, especially when there is involvement of the duodenal wall. Preoperative recognition of this entity is very important in order to avoid unnecessary procedures, although surgery, such as pancreaticoduodenectomy, may still be required to relieve obstructive symptoms. In this article, the pathophysiology and magnetic resonance imaging characteristics of paraduodenal pancreatitis and important benign and malignant mimics are discussed.

Pathologic Subtypes of Ampullary Adenocarcinoma: Value of Ampullary MDCT for Noninvasive Preoperative Differentiation

OBJECTIVE

The purpose of this study was to evaluate the utility of ampullary MDCT in the noninvasive, preoperative differentiation of pancreatobiliary and intestinal subtypes of ampullary adenocarcinoma.

MATERIALS AND METHODS

This retrospective study included 32 patients (20 men, 12 women; age range, 41-81 years) with resected ampullary adenocarcinoma who underwent preoperative contrast-enhanced ampullary MDCT. Two radiologists, blinded to pathologic diagnosis of adenocarcinoma subtype, evaluated the presence of seven MDCT features independently. MDCT findings and ampullary adenocarcinoma subtypes were correlated using chi-square and Fisher exact tests. Interobserver agreement was evaluated using the Cohen kappa statistic.

RESULTS

When evaluated with ampullary MDCT, the intestinal and pancreatobiliary subtypes were significantly different in terms of lesion morphology (p < 0.0001), papillary shape (p < 0.0001), common bile duct (CBD) infiltration and dilatation (p = 0.003 and p = 0.0004, respectively), duodenopancreatic groove infiltration (p = 0.0009), and pancreaticoduodenal artery involvement (p = 0.004). Pancreatobiliary subtype tumors were more often infiltrative in morphology (18/18) and showed retracted papilla (14/18), CBD (18/18) and main pancreatic duct (MPD) infiltration (12/18), dilated CBD (18/18) and MPD (13/18), fixed duodenopancreatic groove appearance (15/18), and pancreaticoduodenal artery involvement (12/18). Intestinal subtype carcinomas were more frequently nodular (14/14) and had a bulging papilla (13/14), a free duodenopancreatic groove appearance (11/14), and no pancreaticoduodenal artery involvement (2/14). When all features were taken into account, MDCT showed sensitivity of 85.7% and specificity of 83.3% in differentiating intestinal and pancreatobiliary subtype tumors. Accuracy, positive predictive value, and negative predictive value of MDCT were 84.4%, 80%, and 88.2%, respectively. Interobserver agreement was almost perfect for the presence of each imaging feature (κ > 0.8).

CONCLUSION

Ampullary MDCT can be useful to differentiate pancreatobiliary and intestinal subtypes of ampullary adenocarcinoma preoperatively, provided the duodenum is optimally distended at imaging.

Optimal Imaging Modalities for the Diagnosis and Staging of Periampullary Masses

Imaging plays a central role in the management of patients with suspected or known periampullary masses, including the initial diagnosis, staging, and follow-up to assess treatment response or recurrence. Use of appropriate imaging tools, application of optimal imaging protocols, and knowledge about imaging findings are essential for the diagnosis and accurate staging of these masses. Structured reporting of the imaging studies offers several advantages over freestyle dictations ensuring completeness of the relevant imaging findings, which would in turn help in deciding the best individual treatment strategy for each patient.

MDCT and MRI of the ampulla of Vater. Part I: technique optimization, normal anatomy, and epithelial neoplasms

The purpose of this two-part article is to review the cross-sectional anatomy of the ampulla and periampullary region, to propose novel and optimized MDCT and MRI techniques that allow accurate evaluation of the ampulla of Vater, and to summarize the cross-sectional imaging features of benign and malignant ampullary conditions. In this first part, we will review the normal anatomy of the ampullary region, provide suggestions on how to optimize evaluation of the ampullary region by MDCT and MRI, and review the imaging features of select epithelial neoplasms of the ampulla. Familiarity with the normal ampullary anatomy and the pathologic conditions involving the ampulla, as well as the use of optimized MDCT and MRI techniques, may improve the diagnostic accuracy of radiologists facing ampullary abnormalities.

Diagnosis, Preoperative Evaluation, and Assessment of Resectability of Pancreatic and Periampullary Cancer

Periampullary region encircles a radius of 2 cm around the ampulla of Vater; accordingly, four distinct neoplasias with overlapping imaging features originate in the region. Each of these lesions has a different long-term prognosis; hence, imaging evaluation to characterize the lesion is important. Further certain specific features pertaining to the vascular invasion and systemic spread may decide about the treatment as well as surgical approach. An understanding of the advances in imaging and image processing technology as well as in the methods of image acquisition, for the purpose, is quite relevant towards etching out a rational pre-treatment evaluation protocol. Further, an evidence-based decision as to the choice of optimum modality for answering specific clinical question is of prime importance in achieving a reasonable post-treatment outcome. Pancreatic adenocarcinoma is the fourth most common cancer and a malignancy with one of the least 5-year survival rates (ranging from 6.8 to 15 % depending on peripancreatic extensions, dropping to 1.8 % for metastatic disease). A survival rate of 15-27 % can be achieved if the lesion is resectable but unfortunately, only 10-15 % of patients are eligible for resection. Cystic tumors of pancreas are a rarer variety of pancreatic neoplasia (5-15 % of pancreatic cysts and 1 % of all pancreatic cancers) which have a much better outcome and chances of resection. Being mostly incidentalomas, a timely differentiation of this lesion from the much more common pseudocyst (which would mandate a medical management and a different surgical protocol) is the key for curability. Lastly, the neuroendocrine tumors of pancreas are equally rare (1 % of all pancreatic tumors), but importantly due to associated clinical syndromes and their capability to metastasize early in the course of disease, a timely detection may hence be the key for successful treatment of these lesions. Imaging plays a vital role in the initial detection and characterization as well as in determination of resectability of each of these pancreatic neoplasias. Further, the differentiation of pancreatic head tumors from other periampullary neoplasias is important; the fact that most recurrences are as a result of surgical intervention in an otherwise inoperable disease while most treatment failures are due to improper characterization of the lesion is notable.

Neuroendocrine neoplasms of the extrahepatic bile duct: radiologic and clinical characteristics

PURPOSE

To retrospectively identify the radiological and clinical features of neuroendocrine neoplasms of the extrahepatic bile duct.

MATERIALS AND METHODS

Institutional review board approval was obtained. Between August 2003 and August 2013, 11 patients (range 41-79 years) who had undergone surgery in our institution for neuroendocrine neoplasms of the extrahepatic bile duct were identified. Clinical features (symptoms, laboratory finding, and medical history) were reviewed. A pathologist reviewed the pathology of 11 patients. CT (n = 11), MRI (n = 10), and PET/CT (n = 8) were reviewed by two radiologists in consensus. They were blinded to the clinical features and pathology report. The tumor location was assessed on CT and was classified as occurring in the common hepatic duct, cystic duct, and common bile duct. The tumor shape was assessed in ten patients using MRI and in one patient using CT. The shape was classified as nodular, intraductal-growing, and periductal-infiltrating type. The FDG activity on PET/CT was also evaluated. Correlation of image findings with pathology was made by a radiologist who didn't participate in the image analysis.

RESULTS

There were five men and six women and their median age was 65 years. On pathology examination, seven patients had neuroendocrine carcinoma (64%), three had mixed adenoneuroendocrine carcinoma (27%), and one had neuroendocrine tumor (9%). CT showed that the tumors were located in the common bile duct in seven patients (64%), the common hepatic duct in two (18%), and the cystic duct in two patients (18%). Five tumors were classified as nodular (45%), five as intraductal-growing (45%), and one as periductal-infiltrating type (9%). PET/CT showed increased FDG activity, ranging from 2.7-15.9, in eight patients with neuroendocrine carcinoma.

CONCLUSION

The most common location of neuroendocrine neoplasms of the extrahepatic bile duct is the common bile duct. Most of them are nodular or intraductal-growing type.