Cystadenomas of the liver and extrahepatic bile ducts: Morphologic and immunohistochemical characterization of the biliary and intestinal variants

Multifaceted involvements of Paneth cells in various diseases within intestine and systemically

Serving as the guardians of small intestine, Paneth cells (PCs) play an important role in intestinal homeostasis maintenance. Although PCs uniquely exist in intestine under homeostasis, the dysfunction of PCs is involved in various diseases not only in intestine but also in extraintestinal organs, suggesting the systemic importance of PCs. The mechanisms under the participation of PCs in these diseases are multiple as well. The involvements of PCs are mostly characterized by limiting intestinal bacterial translocation in necrotizing enterocolitis, liver disease, acute pancreatitis and graft-vs-host disease. Risk genes in PCs render intestine susceptible to Crohn’s disease. In intestinal infection, different pathogens induce varied responses in PCs, and toll-like receptor ligands on bacterial surface trigger the degranulation of PCs. The increased level of bile acid dramatically impairs PCs in obesity. PCs can inhibit virus entry and promote intestinal regeneration to alleviate COVID-19. On the contrary, abundant IL-17A in PCs aggravates multi-organ injury in ischemia/reperfusion. The pro-angiogenic effect of PCs aggravates the severity of portal hypertension. Therapeutic strategies targeting PCs mainly include PC protection, PC-derived inflammatory cytokine elimination, and substituting AMP treatment. In this review, we discuss the influence and importance of Paneth cells in both intestinal and extraintestinal diseases as reported so far, as well as the potential therapeutic strategies targeting PCs.

Mucinous Cystic Neoplasms of the Liver: Epidemiology, Diagnosis, and Management

Mucinous cystic neoplasms (MCNs) are rare tumors of the liver, occasionally seen in the biliary tree. Epidemiologic data are limited by their indolence and recent changes to diagnostic criteria. They are considered premalignant lesions capable of invasive behavior. While their etiology remains unknown, their female predominance, age of onset, and hormonally responsive ovarian-type stroma suggest ectopic organogenesis during embryologic development. MCNs can typically be recognized on imaging; yet, invasiveness is often indeterminate, and percutaneous tissue biopsy has shown limited value. Therefore, complete excision is recommended for all lesions as focal malignant transformation and metastatic disease has been reported.

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.

A rare case of extrahepatic biliary mucinous cystic neoplasm in a middle-aged woman: A case report

Biliary mucinous cystic neoplasms are very rare tumors of the biliary tract with malignant potential. Preoperative diagnosis is challenging, as clinical, biochemical and radiological features are not specific. Surgical resection with negative margins is the gold standard treatment for these uncommon lesions. A 55-year-old woman presented at the Third Department of Surgery (Attikon University Hospital, Athens, Greece) with a history of mild right upper quadrant (RUQ) abdominal pain and jaundice. A 2-cm lesion in the distal common bile was identified by imaging. Following discussion in our multidisciplinary board meeting the patient underwent a pylorus preserving pancreatoduodenectomy, and histopathological examination revealed an ovarian-stromal type intraductal mucinous cystic neoplasm of the extra hepatic biliary. Since biliary mucinous cystic neoplasms are characterized by malignant transformation and high rates of recurrence, surgical resection with negative margins is the treatment of choice for both non-invasive and invasive biliary mucinous cystic neoplasms.

Benign biliary neoplasms and biliary tumor precursors

Benign biliary tumor are common lesions that are often an incidental finding in subjects who undergo medical imaging tests for other conditions. Most are true neoplasms while few result from reactive or malformative proliferation. Benign tumors have no clinical consequences, although the premalignant nature or potential for malignant transformation is of concern in some cases. The main practical problem for pathologists is the need to differentiate them from malignant biliary tumours, which is not always straightforward.

Premalignant lesions of the bile duct have been described, although their incidence has been poorly characterized. These lesions include biliary mucinous cystic neoplasms, intraductal papillary neoplasms of the bile duct, and biliary intraepithelial neoplasia. In this article, histopathology of benign biliary tumors and biliary tumor precursors is discussed, with a focus on the main diagnostic criteria.

Differentiation and management of hepatobiliary mucinous cystic neoplasms: a single centre experience for 8 years

Background

Hepatobiliary mucinous cystic neoplasms (H-MCNs) are relatively rare cystic neoplasms in the liver. The differential diagnosis of H-MCNs remains big challenging, and the management and prognosis between the hepatic simple cyst (HSC) and H-MCNs are quite different. This study aimed to present our experience in the management of H-MCNs and provide a preoperative H-MCNs risk prediction nomogram to differentiating H-MCNs from liver cystic lesions.

Methods

29 patients diagnosed with H-MCNs and 75 patients diagnosed with HSC between June 2011 and June 2019 at Zhejiang University School of medicine, Sir Run-Run Shaw Hospital were reviewed in this study. We analyzed the demographic and clinicopathological variables.

Results

US, CT, and MRI could accurately diagnose only 3.4%, 46.1%, and 57.1% of H-MCNs, respectively. After univariate analysis and multivariate logistic regression analysis, the variables significantly associated with H-MCNs were enhancement after contrast (p = 0.009), tumour located in the left lobe (p = 0.02) and biliary ductal dilation (p = 0.027). An H-MCNs risk predictive nomogram was constructed, which showed excellent discrimination (areas under the receiver operating characteristic curve were 0.940) and consistent calibration between the predicted probability and actual probability.

Conclusion

Among patients with H-MCNs, the location of the tumour, enhancement in CT scan, and biliary duct dilation are significantly independent risk factors. The appropriate treatment of H-MCNs is radical resection. Using our Nomogram could facilitate screening and identification of patients with liver cystic lesions.

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.

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.

Biliary mucinous cystic neoplasm mimicking a hydatid cyst: a case report and literature review

Background

Biliary mucinous cystic neoplasms are rare cystic lesions of the liver which carry pre-malignant potential. Given the scarcity of reports in the literature, they pose a considerable challenge to clinical management, particularly with regards to accurate pre-operative diagnosis.

Case presentation

We present the case of a 37-year-old Tunisian woman who presented with subacute right upper quadrant pain and a large multi-loculated cystic lesion, most consistent with a hydatid cyst. She underwent an open right hepatectomy, and pathology surprisingly revealed a biliary mucinous cystadenoma. Herein, we review the current literature on biliary mucinous cystic neoplasms, with a particular emphasis on diagnostic investigations, key radiological features and optimal treatment modalities.

Conclusion

Biliary mucinous cystic neoplasms require a high index of suspicion and should be managed with complete surgical resection, as conservative techniques are associated with high recurrence rates. Considering the potential for malignant transformation, periodical surveillance imaging is recommended in the post-operative period.

Mucins: the Old, the New and the Promising Factors in Hepatobiliary Carcinogenesis

Mucins are large O-glycoproteins with high carbohydrate content and marked diversity in both the apoprotein and the oligosaccharide moieties. All three mucin types, trans-membrane (e.g., MUC1, MUC4, MUC16), secreted (gel-forming) (e.g., MUC2, MUC5AC, MUC6) and soluble (non-gel-forming) (e.g., MUC7, MUC8, MUC9, MUC20), are critical in maintaining cellular functions, particularly those of epithelial surfaces. Their aberrant expression and/or altered subcellular localization is a factor of tumour growth and apoptosis induced by oxidative stress and several anti-cancer agents. Abnormal expression of mucins was observed in human carcinomas that arise in various gastrointestinal organs. It was widely believed that hepatocellular carcinoma (HCC) does not produce mucins, whereas cholangiocarcinoma (CC) or combined HCC-CC may produce these glycoproteins. However, a growing number of reports shows that mucins can be produced by HCC cells that do not exhibit or are yet to undergo, morphological differentiation to biliary phenotypes. Evaluation of mucin expression levels in precursors and early lesions of CC, as well as other types of primary liver cancer (PLC), conducted in in vitro and in vivo models, allowed to discover the mechanisms of their action, as well as their participation in the most important signalling pathways of liver cystogenesis and carcinogenesis. Analysis of mucin expression in PLC has both basic research and clinical value. Mucins may act as oncogenes and tumour-promoting (e.g., MUC1, MUC13), and/or tumour-suppressing factors (e.g., MUC15). Given their role in promoting PLC progression, both classic (MUC1, MUC2, MUC4, MUC5AC, MUC6) and currently tested mucins (e.g., MUC13, MUC15, MUC16) have been proposed to be important diagnostic and prognostic markers. The purpose of this review was to summarize and update the role of classic and currently tested mucins in pathogenesis of PLC, with explaining the mechanisms of their action in HCC carcinogenesis. It also focuses on determination of the diagnostic and prognostic role of these glycoproteins in PLC, especially focusing on HCC, CC and other hepatic tumours with- and without biliary differentiation.

Intrahepatic biliary cystadenoma mimicking hydatid cyst of liver: a clinicopathologic study of six cases

BACKGROUND

Intrahepatic biliary cystadenomas are rare hepatic neoplasms, which are usually cystic. These tumors are often misdiagnosed as simple liver cysts and hydatid cysts clinically and radiologically owing to nonspecific clinical and radiologic features. These tumors require complete resection, as recurrence and malignant transformation can occur following incomplete excision. It is essential that these tumors be diagnosed accurately so that they can be adequately excised.

METHODS

Clinical and radiological features of six cases of biliary cystadenoma are described.

RESULTS

All of these cases were resected with the clinical and/or radiological impression of simple liver cysts and/or hydatid cysts. Out of the six patients, five were female and one was male. Ages of the patients ranged from 28 to 60 years (mean 45 years). The patients presented with nonspecific symptoms. Internal septations were seen on preoperative imaging (when available). On gross examination, all tumors were cystic; their sizes varied from 5.5 to 14 cm, mean size was 9.0 cm. On histopathologic examination, cystic spaces were lined by cuboidal to columnar mucin-secreting epithelium with underlying ovarian-type stroma. In one case, ovarian-type stroma was not seen. Recurrence was seen in three cases at 1 to 5 years of follow up.

CONCLUSIONS

Owing to their malignant potential and high recurrence rate following incomplete resection, an aggressive surgical approach is recommended. Prognosis is excellent after complete resection.

Nonmucinous Biliary Epithelium Is a Frequent Finding and Is Often the Predominant Epithelial Type in Mucinous Cystic Neoplasms of the Pancreas and Liver

Mucinous cystic neoplasms (MCNs) can occur in the pancreas and liver. Classically, these cystic lesions are lined by columnar mucinous epithelium with underlying ovarian-type stroma. It has been proposed that cysts with ovarian-type stroma and nonmucinous epithelium be considered separate entities in both the pancreas and liver. Using a series of 104 pancreatic and 32 hepatic cases, we aimed to further characterize the epithelium present in MCNs. Mucinous epithelium was defined as pancreatic intraepithelial neoplasia-like columnar cells with pale pink/clear apical mucin. Epithelial cells ranging from flat to cuboidal to short columnar without obvious mucin or goblet cells were classified as nonmucinous/biliary epithelium. A mixture (at least 5%) of mucinous and nonmucinous/biliary epithelium was noted in 81%. Almost half (47%) of the cases had abundant (>50%) nonmucinous/biliary epithelium. Of the 71 cases with ≤50% nonmucinous/biliary epithelium, 8 cases demonstrated high-grade dysplasia (7 pancreas, 1 liver) and 14 demonstrated invasive adenocarcinoma (11 pancreas, 3 liver). Conversely, of the 58 cases with >50% nonmucinous/biliary epithelium, not a single case of high-grade dysplasia (P=0.007) or invasive carcinoma (P<0.001) was identified. In summary, nonmucinous/biliary epithelium frequently occurs in MCNs of the pancreas and liver. As mucinous and nonmucinous/biliary epithelia often occur together, there does not appear to be enough evidence to regard cases with predominantly nonmucinous/biliary epithelium as separate entities. Our findings suggest that mucinous change is a "progression" phenomenon in MCNs of the pancreas and liver, and only when abundant mucinous epithelium is present is there a risk of progression to malignancy.