Intraductal papillary cholangiocarcinoma associated with von Meyenberg complexes: a case report

von Meyenburg complexes are more frequently associated with cholangiocarcinoma

AIM

There is some evidence that von Meyenburg complexes (VMCs) can progress to cholangiocarcinoma (CC). This study aimed to evaluate the prevalence of VMCs in CC cases.

METHODS

All hepatic resections and explants with intra-hepatic CC (I-CC) and hilar-CC (H-CC) from 1985 to 2020 were studied. Hepatic resections (n=68) for benign lesions or metastatic colonic carcinoma and 15 cases with cirrhosis without any cancer were used as controls.

RESULTS

A total of 118 cases of CC (88 I-CC, 30 H-CC) were identified. Of these, 61 (52%) patients had no known background liver disease, and 20 (17%) had cirrhosis. Associated liver disorders included metabolic dysfunction-associated steatohepatitis (23), chronic viral hepatitis B or C (13), biliary disease (primary or secondary sclerosing cholangitis) (8), polycystic kidney disease (6), cryptogenic cirrhosis (5) and others miscellaneous disorders (7). VMCs were present in 34 (39%) of 88 I-CC cases and 7 (23%) of 30 H-CC cases. VMCs were present within the tumour (20 cases), outside the cancer (21 cases) or at both locations (10 cases). VMCs with dysplasia/carcinoma in situ were seen in 19 of 41 (46%) cases with CC and VMCs. In addition, bile duct adenomas were identified in 6 (5%) of CC. 7% of controls showed the presence of VMCs compared with 35% of CC cases (p<0.05).

CONCLUSIONS

VMCs are seen far more frequently in patients with CC than in the control group. The findings support the hypothesis that VMCs could represent a precursor of CC or a marker for a higher risk of developing CC.

Biliary Duct Hamartomas: A Systematic Review

Biliary duct hamartomas are benign intrahepatic bile duct lesions. Despite being primarily incidental findings on imaging, these lesions can provide a diagnostic conundrum due to their shared characteristics with malignant tumors. The goal of this systematic review is to offer a thorough clinical profile of biliary duct hamartomas. There were 139 cases of biliary duct hamartomas identified in a structured systematic review of the literature. Patient demographics, clinical presentation, significant laboratory and imaging data, diagnostic modalities, treatment choices, and outcomes were all studied and reported. Biliary duct hamartomas present with mild symptoms and laboratory abnormalities, and while being visible on imaging, the results are non-specific and may require biopsy in case of red flag signs such as weight loss and a progressive increase in the size of the lesion. Furthermore, there are currently no published guidelines for the treatment of biliary duct hamartomas, and many people have had surgery despite the clinically benign nature of these abnormalities. As per the findings of the study, individuals who exhibit signs of malignancy should be investigated further. Eyeballing for red flag symptoms, followed by a specialized imaging scan and invasive treatment, is the three-step approach to biliary duct hamartomas. Since our recommendations include a shift in strategy and do not contradict existing rules, there are likely to be few roadblocks to improvement; the key barriers being technological equipment and image quality. In this study, we intended to pave the way for future research in the field. In our opinion, the next decade will bring a better understanding of the characteristics of biliary hamartomas, disease symptoms, and better recognition of any suspicious features. These indications will aid in reducing the number of unneeded surgical or invasive operations. Finally, the findings of these future studies will allow the medical community to improve and provide the best care possible.

Malignant Transformation in Von-Meyenburg Complexes: Histologic and Immunohistochemical Clues With Illustrative Cases

Benign developmental defects known as Von-Meyenburg complexes (VMCs) have been postulated to progress to cholangiocarcinoma (CC) in rare instances. Although a gradual, sequential histologic transition from VMCs to CC has been described in some of these cases, the underlying genetic mechanism is yet to be elucidated. Here, we review the literature to put together a report on the clinicopathologic features and immunohistochemical changes associated with such transformation. We also review the documented association between CC and p16 inactivation, and discuss a possible role for this mechanism to contribute in VMCs to CC progression. In addition, using 2 illustrative cases encountered at our institute, we provide morphologic and immunohistochemical clues that can be used to detect such progression from hamartoma to malignancy. These cases and the accompanying review of literature further solidify the association between VMCs and CC.

Tumoral Versus Flat Intraepithelial Neoplasia of Pancreatobiliary Tract, Gallbladder, and Ampulla of Vater

Context.—The identification of a precursor lesion is important to understanding the histopathologic and genetic alterations in carcinogenesis. There are a plethora of terminologies that describe precursor lesions of the pancreatobiliary tract, ampulla of Vater, and gallbladder. The current terminologies for precursor lesions may make it difficult to understand the tumor biology. Here, we propose the concept of tumoral and flat intraepithelial neoplasia to improve our understanding of precursor lesions of many epithelial organs, including the pancreatobiliary tract, ampulla of Vater, and gallbladder.

Objective.—To understand the dichotomous pattern of tumoral and flat intraepithelial neoplasia in carcinogenesis of pancreatobiliary tract, ampulla of Vater, and gallbladder.

Data Sources.—Review of relevant literatures indexed in PubMed.

Conclusions.—Tumoral intraepithelial neoplasia presents as an intraluminal or intraductal, mass-forming, polypoid lesion or a macroscopic, visible, cystic lesion without intracystic papillae. Microscopically, tumoral intraepithelial neoplasia shows various proportions of papillary and tubular architecture, often with a mixed pattern, such as papillary, tubular, and papillary-tubular. The malignant potential depends on the degree of dysplasia and the cell phenotype of the epithelium. Flat intraepithelial neoplasia presents as a flat or superficial, spreading, mucosal lesion that is frequently accompanied by an invasive carcinoma. Tumoral and flat intraepithelial neoplasias are not homogeneous entities and may exhibit histopathologic spectrum changes and different genetic profiles. Although intraepithelial neoplasia showed a dichotomous pattern in the tumoral versus flat types, they can coexist. Tumoral and flat intraepithelial neoplasia can be interpreted as part of a spectrum of changes in the carcinogenesis pathway of each organ.

Clinical and biological significance of precursor lesions of intrahepatic cholangiocarcinoma

Cholangiocarcinoma (CC) is primarily a malignant tumor of older adults most prevalent in Southeast Asia, where liver fluke infestation is high. However the etiology in western countries is unknown. Although the incidence of extrahepatic cholangiocarcinoma has remained constant, incidence of intrahepatic CC (ICC) which differs in morphology, pathogenesis, risk factors, treatment and prognosis is increasing. While this increase is associated with hepatitis C virus infection, chronic nonalcoholic liver disease, obesity, and smoking, the pathogenesis of ICC and molecular alterations underlying the carcinogenesis are not completely elucidated. Benign biliary lesions such as biliary intraepithelial neoplasia, intraductal papillary neoplasm of the bile duct, von Meyenburg complex or bile duct hamartoma, and bile duct adenoma have been associated with ICC. For each of these entities, evidence suggests or supports a role as premalignant lesions. This article summarized the important biological significance of the precursor lesions of ICC and the molecular mechanisms that may be involved in intrahepatic cholangiocarcinogenesis.

Molecular evidence for the neoplastic potential of hepatic Von-Meyenburg complexes

Von-Meyenburg complexes (VMCs) have been shown to progress to cholangiocarcinoma (CC) in some cases. Histologic examination in such cases reveals a gradual transition of VMCs to intermediate lesions and finally to CC. The goal of this study was to determine if this histologic progression was also accompanied by sequential genetic alterations. Two cases that showed many VMCs with a transition to cholangiocarcinoma through intermediate lesions were analyzed. Multiple VMCs (away from the tumor), intermediate lesions and areas of frank CC were microdissected under stereoscopic guidance and were analyzed for allelic imbalance [loss of heterozygosity (LOH)] using a panel of 20 polymorphic microsatellite markers by polymerase chain reaction/electrophoresis. The 2 cases of CCs revealed LOH at 5 and 7 different genomic loci specific for each patient, respectively. Coexisting VMCs also exhibited LOH ranging from 0 to 3 loci in each case. Intermediate lesions showed LOH at a single locus in case 1, whereas the assay could not be performed in case 2 due to inadequate DNA yield. In case 2, the earliest acquired mutations were present in the VMCs supporting a causal relationship for neoplastic progression. Discordant LOH mutations were also present in the VMCs and the adenomatous lesions providing support that LOH detected at these sites did not passively migrate or reflect contamination. The results of the present study show that the histologic progression observed through these stages is also accompanied by LOH at loci harboring key oncogenes. The findings also support that VMCs are preneoplastic lesions that could progress to CC with time.

Intrahepatic cholangiocarcinoma arising in multiple bile duct hamartomas: report of two cases and review of the literature

Multiple bile duct hamartomas (BDHs)/von Meyenburg complexes, are tumor-like lesions of the liver. Malignant transformation in BDHs has been previously reported in very rare instances, and the most common tumor arising in this clinical setting is cholangiocarcinoma. Herein, we report on clinicopathological findings in two cases of cholangiocarcinoma occurring in liver with multiple BDHs. Histopathologically, multiple BDHs showed morphologic transition from clearly benign to dysplasia or carcinoma in situ, then to invasive carcinoma sequence of the biliary epithelium. The neoplastic epithelium showed positivity for cytokeratin 19, CA 19-9, and epithelial membrane antigen. Staining for Hep Par 1, alpha-fetoprotein, cytokeratin 20, and alpha1-antitrypsin was negative. All sections from the non-neoplastic liver in each specimen showed multiple BDHs. Any other clinically detectable primary tumor was not found. These two neoplasms were interpreted as a cholangiocarcinoma arising in BDHs. This suggested BDHs might be a risk factor of development of cholangiocarcinoma.