Ultrasound Findings of Intraductal Papillary Neoplasm in Bile Duct and the Added Value of Contrast-Enhanced Ultrasound

SIUMB recommendations on the use of ultrasound in neoplastic lesions of the gallbladder and extrahepatic biliary tract

Extrahepatic biliary tract and gallbladder neoplastic lesions are relatively rare and hence are often underrepresented in the general clinical recommendations for the routine use of ultrasound (US). Dictated by the necessity of updated summarized review of current literature to guide clinicians, this paper represents an updated position of the Italian Society of Ultrasound in Medicine and Biology (SIUMB) on the use of US and contrast-enhanced ultrasound (CEUS) in extrahepatic biliary tract and gallbladder neoplastic lesions such as extrahepatic cholangiocarcinoma, gallbladder adenocarcinoma, gallbladder adenomyomatosis, dense bile with polypoid-like appearance and gallbladder polyps.

Mucin-producing Cystic Hepatobiliary Neoplasms: Updated Nomenclature and Clinical, Pathologic, and Imaging Features

Cystic hepatobiliary neoplasms with mucin-producing epithelium-mucinous cystic neoplasm of the liver (MCN) and intraductal papillary neoplasm of the bile duct (IPNB)-are rare and distinct entities that have unique clinical, pathologic, and imaging features. They are differentiated pathologically by the presence of subepithelial ovarian-like hypercellular stroma (OLS), which is the defining histopathologic feature of MCN. MCN is commonly a benign, large, solitary, symptomatic, multiloculated cystic mass without biliary communication that occurs in middle-aged women. On the other hand, IPNBs are a heterogeneous spectrum of tumors, which are commonly associated with invasive carcinoma, occur in older patients, and can be differentiated from MCN by communication with the biliary tree, intraductal masses, associated biliary ductal dilatation, and absent OLS. Understanding of these rare neoplasms has grown and evolved over time and continues to today, but uncertainty and controversy persist, related to the rarity of these tumors, relatively recent designation as separate entities, inherent clinicopathologic heterogeneity, overlapping imaging features, and the fact that many prior studies likely included MCN and cystic IPNB together as a single entity. Confusion regarding these neoplasms is evident by historical inconsistencies and nonstandardized nomenclature through the years. Awareness of these entities is important for the interpreting radiologist to suggest a particular diagnosis or generate a meaningful differential diagnosis in the appropriate setting, and is of particular significance as MCN and cystic IPNB have overlapping imaging features with other more common hepatobiliary cystic masses but have different management and prognosis. Online supplemental material is available for this article. Work of the U.S. Government published under an exclusive license with the RSNA.

Intrahepatic intraductal papillary cystic neoplasm of the bile duct: A case report

Introduction and importance

Intraductal papillary neoplasm of the bile duct (IPNB) is a tumour with a very low incidence in the Western world, characterised by a high risk of malignant transformation and unknown prognosis. It is a new entity which was adopted by the WHO in 2010 as a precursor lesion of cholangiocarcinoma. Intrahepatic bile duct is the most common site of origin for IPNB.

Case presentation

Hereby, we present a case of an asymptomatic 63- year-old man, referred to our department after routine ultrasonography showing a multifocal cystic lesion on the left hepatic lobe. Further screening modalities (CT, MRI abdo) confirmed a complex cystic liver lesion with atypical features. The patient underwent left hepatectomy. Histopathology showed a cystic type intrahepatic IPNB, which was completely resected (R0). The follow up in 2 yrs post-operation showed no signs of recurrence.

Clinical discussion

The diagnosis and management of IPNB remain challenging. A multimodality imaging approach is essential in order to diagnose IPNB, assess tumour location and extent and plan the optimal treatment strategy.

Conclusion

Complete surgical resection (R0) with close postoperative follow-up offers long-term survival.

Long-term growth of intrahepatic papillary neoplasms: A case report

BACKGROUND

Intraductal papillary neoplasm of the bile duct (IPNB) is a type of tumor that presents in the intra- or extrahepatic bile ducts. Cystic-type intrahepatic IPNB often mimics simple liver cysts, making the diagnosis difficult. Because the growth of IPNB is slow, careful follow-up and timely therapeutic intervention is recommended. There are few reports with a follow-up period longer than a decade; thus, we report the case of a patient with an IPNB that grew for over 13 years.

CASE SUMMARY

A 65-year-old man was diagnosed, 13 years prior with a cystic hepatic tumor with abnormal imaging findings. The targeted tumor biopsy results showed no malignancy. Biannual follow-up examinations were performed because of the potential for malignancy. The cystic lesions showed gradual enlargement over 11 years and a 4 mm papillary proliferation appeared on the cyst wall, which is compatible with IPNB. The tumor was observed for another 2 years because of the patient’s wishes. The imaging findings showed enlargement to 8 mm and a new 9 mm papillary proliferation of the cystic tumor. Contrast-enhanced ultrasonography showed hyperenhancement during the arterial phase in both cyst walls, indicating intraductal tumor progression in both tumors. Thus, liver segment 8 subsegmentectomy was performed. The pathological findings indicated that the tumors contained mucin, and high-grade atypia was observed in the papillary lesions, showing IPNB.

CONCLUSION

The development of IPNB should be monitored in patients with cystic lesions and ultrasonography are useful tool for the evaluation.

Accuracy of Contrast-Enhanced Ultrasound in the Diagnosis of Bile Duct Obstruction

PURPOSE

To investigate the ability of contrast-enhanced ultrasound (CEUS) to differentiate benign from malignant lesions causing biliary duct obstruction.

MATERIALS AND METHODS

Between November 2006 and December 2013, 59 patients with bile duct obstruction of undetermined cause in baseline ultrasound underwent CEUS study. The enhancement and posterior washout were analyzed in real time all along the study duration (5'). The final diagnosis suggested by CEUS was compared with histologic diagnosis (47.5%) or with radiologic follow-up with TC, RM or ERCP.

RESULTS

Final diagnoses included 42 malignant lesions (cholangiocarcinoma n=22, metastases n=6, pancreatic carcinoma n=6, hepatocarcinoma n=4, gallbladder carcinoma n=2, ampullary carcinoma n=1 and lymphoma n=1) and 17 benign lesions (lithiasis or biliary sludge n=15, xanthogranulomatous cholecystitis n=1 and indeterminate n=1). CEUS accuracy compared with final diagnoses based on combined reference standard was 86.4%. CEUS correctly identified 36 of 42 malignant lesions (sensibility 85.7%) and 15 of 17 benign lesions (specificity 88.2%). The positive predictive value of CEUS for malignancy was 94.7%, while the negative predictive value was 71.4%.

CONCLUSION

CEUS is useful to differentiate between benign and malignant causes of obstructive jaundice. This technique improves the detection of bile duct invasion in hepatic neoplasms and permits better evaluation of intra- and extraductal extension of hilar hepatobiliary tumors.