Comparative radiological pathological study of biliary intraductal tubulopapillary neoplasm and biliary intraductal papillary mucinous neoplasm

Beyond cholangiocarcinoma: imaging features of mimicking pathologies in the biliary tract

Cholangiocarcinoma (CCA) is the second most common primary malignancy of the hepatobiliary system and presents as a heterogeneous disease with three distinct morphological subtypes: mass-forming, periductal-infiltrating, and intraductal-growing, each characterized by distinguishing imaging features. Accurate diagnosis of CCA is challenging due to the overlap of imaging findings with a broad range of benign and malignant conditions. Therefore, it is essential for radiologists to recognize these mimickers and offer a reasonable differential diagnosis, as this has a significant impact on patient management. Although histopathological confirmation is often required for a definitive diagnosis, understanding specific imaging characteristics that differentiate CCA from its mimickers is crucial. This article highlights a variety of benign and malignant conditions that resemble CCA on imaging, emphasizing features that enhance diagnostic accuracy in clinical practice.

A Review of Type 1 and Type 2 Intraductal Papillary Neoplasms of the Bile Duct

Intraductal papillary neoplasm of the bile duct (IPNB) is a heterogeneous disease similar to intraductal papillary mucinous neoplasm of the pancreas. These lesions have been recognized as one of the three major precancerous lesions in the biliary tract since 2010. In 2018, Japanese and Korean pathologists reached a consensus, classifying IPNBs into type l and type 2 IPNBs. IPNBs are more prevalent in male patients in East Asia and are closely related to diseases such as cholelithiasis and schistosomiasis. From a molecular genetic perspective, IPNBs exhibit early genetic variations, and different molecular pathways may be involved in the tumorigenesis of type 1 and type 2 IPNBs. The histological subtypes of IPNBs include gastric, intestinal, pancreaticobiliary, or oncocytic subtypes, but type 1 IPNBs typically exhibit more regular and well-organized histological features than type 2 IPNBs and are more commonly found in the intrahepatic bile ducts with abundant mucin. Due to the rarity of these lesions and the absence of specific clinical and laboratory features, imaging is crucial for the preoperative diagnosis of IPNB, with local bile duct dilation and growth along the bile ducts being the main imaging features. Surgical resection remains the optimal treatment for IPNBs, but negative bile duct margins and the removal of lymph nodes in the hepatic hilum significantly improve the postoperative survival rates for patients with IPNBs.

MRI features of intraductal papillary mucinous neoplasm of the bile ducts, "The myth about the cyst": A systematic review

Rationale and objectives

Intraductal papillary mucinous neoplasm of the bile ducts (IPMN-B) is a true pre-cancerous lesion, which shares common features with pancreatic IPMN (IPMN-P). While IPMN-P is a well described entity for which guidelines were formulated and revised, IPMN-B is a poorly described entity.We carried out a systematic review to evaluate the existing literature, emphasizing the role of MRI in IPMN-B depiction.

Materials and methods

PubMed database was used to identify original studies and case series that reported MR Imaging features of IPMN-B. The search keywords were "IPMN OR intraductal papillary mucinous neoplasm OR IPNB OR intraductal papillary neoplasm of the bile duct AND Biliary OR biliary cancer OR hepatic cystic lesions". Risk of bias and applicability were evaluated using the QUADAS-2 tool.

Results

884 Records were Identified through database searching. 12 studies satisfied the inclusion criteria, resulting in MR features of 288 patients. All the studies were retrospective. Classic features of IPMN-B are under-described. Few studies note worrisome features, concerning for an underlying malignancy. 50 % of the studies had a high risk of bias and concerns regarding applicability.

Conclusions

The MRI features of IPMN-B are not well elaborated and need to be further studied. Worrisome features and guidelines regarding reporting the imaging findings should be established and published. Radiologists should be aware of IPMN-B, since malignancy diagnosis in an early stage will yield improved prognosis.

Intraductal tubulopapillary neoplasms of the bile ducts: identity, clinicopathologic characteristics, and differential diagnosis of a distinct entity among intraductal tumors

Among the mass-forming preinvasive (tumoral intraepithelial) neoplasms of the biliary tract, intraductal tubulopapillary neoplasms (ITPN-Bs) are increasingly being recognized as a separate category. By being intramucosal polypoid proliferations of dysplastic/neoplastic cells, they are highly similar to other members of the "intraductal neoplasms (IDNs)" category (namely, intraductal papillary neoplasms [IPNBs], and intraductal oncocytic papillary neoplasms [IOPNs]); however, they are distinguished by MUC6-expressing nonmucinous cells that lack intestinal differentiation and form striking tubular configuration. Their molecular/genetic profile is also proving to be different with frequent alterations in cell cycle and chromatin remodeling genes, which are quite uncommon in other IDNs and cholangiocarcinomas. Despite the conceptual overlaps, they are also very different from intracholecystic nonmucinous tubular neoplasms (ICTN) of the gallbladder with the latter being associated with Wnt/beta-catenin pathway alterations, and almost never invasive. In contrast, ITPN-Bs are invasive in an estimated 80% of the cases, although even invasive examples often exhibit a protracted course. Invasive carcinomas arising from ITPN-Bs are overall similar to cholangiocarcinomas (including small duct and large duct patterns) but also often have peculiar characteristics such as more nodular-compact (blunt invasion) pattern. Like other IDNs, the ITPN-Bs have also been classified in the past as intraductal-spreading type of cholangiocarcinomas (and they are still regarded as such in some publications). In small biopsies, they are prone to be mistaken as ordinary adenocarcinomas because of their tubular pattern and pancreatobiliary cytology although their relatively monotonous cytology and zones of back-to-back tubule formation can help in their correct identification. Clinical presentation of ITPN-Bs is generally similar to other intraductal neoplasms; however, in the intrahepatic component, they tend to be more nodular than cystic, and their snake-like intraductal growth pattern is often more striking. In the management (diagnosis and treatment) of these tumors that are in essence adenoma-carcinoma sequence, the invasive and noninvasive components ought to be evaluated separately. Minimally invasive examples are commonly curable, and even those more extensively invasive may have a surprisingly good prognosis. In summary, biliary ITPNs form a distinct category not only clinicopathologically, immunophenotypically, and molecular-wise but regarding their biological behavior as well.

Intraductal tubulopapillary neoplasms of the pancreas and biliary tract: The black swan of hepatobiliary surgery

Intraductal tubulopapillary neoplasms (ITPNs) of the pancreas and biliary tract are rare pre-malignant entities of the biliary tract and pancreas that are difficult to diagnose preoperatively. While there are imaging characteristics that can differentiate these lesions from more common entities like adenocarcinoma or intraductal papillary mucinous neoplasms (IPMN), ITPNs are not always distinctive. Herein we present two cases of ITPN, one of biliary and the other of pancreatic origin, which had a preoperative diagnosis of cholangiocarcinoma and IPMN, respectively. We discuss our findings in these cases, patient presentation and course, review the radiographic and pathologic findings, and propose a more effective approach to the preoperative workup and diagnosis of ITPN based on our review of the contemporary literature.

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.

Cystic biliary tumors of the liver: diagnostic criteria and common pitfalls

With major advancements and frequent use of abdominal imaging techniques, hepatic cysts are increasingly encountered in clinical practice. Although the majority of cysts are benign, a small subset represents neoplastic precursors to cholangiocarcinoma. These cystic precursors include intraductal papillary neoplasms of the bile duct (IPNB) and mucinous cystic neoplasms of the liver (MCN-L), and bear striking pathologic resemblance to corresponding cystic neoplastic precursors within the pancreas. This review examines the salient clinical, gross, microscopic and molecular features of IPNBs and MCN-Ls, and, in particular, provides histopathologic comparison to their pancreatic counterparts. Considering these neoplasms may be diagnostically challenging, we also discuss other hepatic lesions within the differential diagnosis, and the potential for molecular methods to improve their preoperative evaluation and the early detection of cholangiocarcinoma.

Balloon Extraction of an Intraductal Tubulopapillary Neoplasm of the Bile Duct During Endoscopic Retrograde Cholangiopancreatography

Intraductal tubulopapillary neoplasm (ITPN) of the bile duct is a rare type of intraductal neoplasm of the bile duct that has mainly been described in the literature in case reports and small case series. Only within the past decade has ITPN of the bile duct been identified as its own entity and have definitive diagnostic criteria been established. Given its rarity, there is no standard of care for treatment. Here, we describe a case report of biliary ITPN diagnosed in a unique manner.

Cystic liver neoplams: A single centre experience and literature review

INTRODUCTION

The hepatic cystic tumour is a very rare neoplasm, representing about 5% of all cystic liver neoplasms. The preoperative diagnosis is difficult and can lead to confusion. The aim of this study is to analyze a number of cases operated at our centre with an histologic diagnosis of liver cystic neoplasms and also to describe the sintomathology, diagnosis and management as per the recent classification.

METHODS

A retrospective analysis was performed including all the cystic liver neoplasms operated between January 2000 and December 2019. The study was performed based on the pre-existing pathology archives. The 2010 previous cases were reclassified following the new 2010 OMS classification.

RESULTS

The study sample was of 10 patients, identifying 6 of them as mucinous cystic liver neoplasms, and the other 4 as intraductal papillary biliary neoplasms. The majority of the patients were women (8/10) and the median age was 47 years. Regarding the treatment, 3 hepatectomy and 7 enucleations were performed. Frozen section intraoperatively was not required in any case. In one case, variable cellular atypia with areas of adenocarcinoma was observed, and the patient received neoadyuvant chemotherapy with taxol and carboplatin. In all cases the resection margins were negative.

CONCLUSION

Cystic liver neoplasms are infrequent tumours with a difficult differential diagnosis. Therefore, with a high radiological suspicious, the treatment should be a complete resection to avoid recurrences and malignancies.

Magnetic Resonance Imaging versus Computed Tomography for Biliary Tract Intraductal Papillary Mucinous Neoplasm (BT-IPMN): A Diagnostic Performance Analysis

BACKGROUND In most cases, biliary tract intraductal papillary mucinous neoplasm (BT-IPMN) is depicted by pathological features rather than on imaging modalities, but fine-needle aspiration cytology cannot provide complete information on tumor(s). Computed tomography (CT) has the advantage of high spatial resolution and multiplanar capabilities, while magnetic resonance imaging (MRI) has greater contrast resolution than CT. The purpose of this study was to compare the diagnostic performance of CT vs. MRI for the diagnosis of BT-IPMN using surgical pathology as the reference standard. MATERIAL AND METHODS Data from CT, MRI, and surgical pathology of 210 patients with complaints of abdominal discomfort, vomiting, and/or jaundice for at least 6 months were included in the analysis. Intra-observer agreements for diagnosis of neoplasm was evaluated by kappa statistics. RESULTS CT and MRI respectively detected 171 and 33 patients with BT-IPMN, 6 and 176 with biliary intraductal tubulopapillary neoplasms (BT-ITPN), and 28 and 6 with inconclusive results. Surgical pathology reported 179 patients with BT-IPMN and 25 patients with BT-ITPN. CT and MRI both had the same accuracy (97.14%) for BT-IPMN. The sensitivities for diagnosis of BT-IPMN were 87.75%, 83.81%, and 81.43% for the surgical pathology, MRI, and CT, respectively. Intra-observer agreements for diagnosis of neoplasm were substantial (k=0.79), perfect (k=0.81), and perfect (k=0.85) for CT, MRI, and surgical pathology, respectively. CONCLUSIONS MRI appears to be a more accurate and reliable method than CT for depicting BT-IPMN.

Premalignant Lesions of the Biliary Tract

Although the most common presentation of biliary disorder in North America is secondary to gallstone disease, an awareness of benign biliary cystic neoplasms is important because of the risk of malignant transformation. The incidence of premalignant cystic neoplasms of the bile duct is not well characterized and they often are detected incidentally for suspicion of other abdominal disorders. This article describes the 4 most common premalignant biliary cystic neoplasms: biliary mucinous cystic neoplasms, intraductal papillary mucinous neoplasms of the bile duct, intraductal tubular papillary neoplasms of the bile duct, and choledochal cysts.

Uncommon Intraluminal Tumors of the Gallbladder and Biliary Tract: Spectrum of Imaging Appearances

Intraluminal pathologic conditions of the bile ducts and gallbladder are common, most frequently consisting of calculi and adenocarcinoma. In recent years, intraductal papillary neoplasm of the bile ducts (IPN-B), which is analogous to intraductal papillary mucinous neoplasm of the pancreas, has been recognized as a distinct pathologic entity and a precursor lesion to adenocarcinoma of the bile ducts. Intraductal tubulopapillary neoplasm (ITPN) of the bile duct was subsequently described as a distinct pathologic entity. With increased awareness and advances in imaging techniques, these lesions are diagnosed with increased frequency at preoperative imaging. A similar neoplasm in the gallbladder is referred to as intracholecystic papillary neoplasm. These lesions are often diagnosed at a preinvasive stage and have a better prognosis than invasive cholangiocarcinoma when treated with curative resection, underscoring the importance of an accurate imaging diagnosis. The most common causes of polypoid lesions of the gallbladder are cholesterol polyps and adenomyomatosis. These lesions need to be differentiated from the less common but clinically important adenocarcinoma of the gallbladder. Imaging is crucial to identify polyps that are at high risk for malignancy so that the appropriate management choice between imaging follow-up and cholecystectomy can be made by the treating physicians. Other less common gallbladder tumors, such as gallbladder adenomas, lymphoma, and metastases to the gallbladder, can manifest as intraluminal tumors; and awareness of these lesions is also important. In this article, the recent literature is reviewed; and the imaging appearances, histopathologic findings, and management of uncommon intraluminal tumors of the bile ducts and gallbladder and their mimics are discussed. ^©RSNA, 2019.

Intraductal papillary neoplasm of the bile duct: a single-center retrospective study

Objective Intraductal papillary neoplasm of the bile duct (IPNB) has been increasingly recognized and reported. However, its clinical features are still controversial because of its low incidence. In the present study, we investigated the characteristics of IPNB. Methods In total, 28 patients with IPNB were treated at our institution from January 2000 to December 2016. Clinical data were collected and a retrospective accurate database was constructed. Demographic characteristics, perioperative management, and prognosis were retrospectively analyzed. Results Abdominal discomfort was the most common symptom. Preoperative imaging revealed biliary tract dilatation in 23 patients. Left lateral or left hepatic lobectomy was the most frequently performed surgical procedure. Histological analysis revealed malignancy in 17 patients. Eighty-eight lymph nodes were swept from the patients with malignant disease, but only three were metastatic. Twenty-one patients were followed up for 3 to 60 months (mean, 29.4 ± 18.2 months). Seven patients died during the follow-up period. Patients with benign tumors had significantly greater disease-free survival. Conclusions IPNB is a rare biliary disease that occurs mainly in patients of advanced age. The most common symptom is abdominal discomfort. Lymphatic metastasis is uncommon. Patients with benign tumors may have a better prognosis than those with malignant tumors.