Adenocarcinoid of the liver arising within an area of hamartoma with predominant bile duct component

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.

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.

Hepatocellular carcinoma arising in association with von-Meyenburg's complexes: an incidental finding or precursor lesions? A clinicopatholigic study of 4 cases

Biliary hamartomas or von-Meyenburg complexes form part of a spectrum of ductal plate malformation that includes polycystic liver disease, congenital hepatic fibrosis, and Caroli disease. These lesions are known to have neoplastic transformation. Development of intrahepatic cholangiocarcinoma is well described in these complexes. Rarely, hepatocellular carcinomas (HCCs) have been seen in association with bile duct hamartomas, however; it is not clear whether development of HCC is an epiphenomenon unrelated to the precursor lesion or biliary hamartomas may progress to liver cancers. We herein report 4 interesting cases of hepatitis C virus-, alcohol-, and nonalcoholic fatty liver disease-associated end-stage liver disease with coexisting HCC and multiple large von-Meyenburg complexes.

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.

Cholangiocarcinoma arising in von Meyenburg complexes: report of four cases

Although von Meyenburg complexes (VMC) are largely considered to be innocuous, neoplastic transformations have been described. The present report describes four cases of cholangiocarcinoma (CC) occurring on a background of VMC. The patients were all male and aged 69, 59, 68 and 75 years, respectively. While two patients were asymptomatic, the other two had a history of colon cancer. Radiologically the tumors measured 3, 4, 4.5 and 10 cm and were well enhanced from the arterial to delayed portal phase. Microscopically, the tumor consisted of multiple foci of characteristic VMC, and had a gradual transition from VMC to hyperplasia or dysplasia and well- to moderately differentiated adenocarcinomas. One patient had combined hepatocellular carcinoma (HCC) and CC, occurring in the high grade dysplastic nodule and VMC. On immunohistochemistry the epithelial cells of the VMC and CC were immunopositive for cytokeratin (CK) 7 in three patients, with another patient being focally positive only for CK19. The Ki-67 labeling indices increased from the VMC to the dysplastic areas and then to the carcinomas. As a potentially precancerous lesion, VMC should be carefully followed up in terms of any size increases. Thus, biopsies are essential to determine any proliferative epithelial changes including dysplasia and malignant transformation.

Imaging findings of biliary hamartomas (von Meyenburg complexes)

To evaluate the imaging findings of biliary hamartomas (von Meyenburg complexes, vMCs) and discuss their differential diagnosis from other related diseases, imaging findings of biliary hamartomas on ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), magnetic resonance cholangiopancreatography (MRCP), and hepatobiliary scintigraphy were prospectively analyzed in six patients. On ultrasound images, five of the six cases showed multiple small hyper- and hypoechoic lesions with comet-tail echoes, especially when magnified using the zoom function. In all six cases, multiple tiny hypodense lesions less than 10 mm in diameter were scattered throughout the liver with no enhancement on CT. These tiny lesions were demonstrated to be hyper- and hypointense on T2- and TI-weighted images, respectively, in three patients who underwent MRI examinations. MRCP was performed in two patients, and it clearly showed multiple tiny round and irregular-shaped hyperintense lesions. MRCP and hepatobiliary scintigraphy showed normal appearances of intra- and extrahepatic bile ducts in two and one patients, respectively. Imaging modalities are useful in the diagnosis and differential diagnosis of vMCs. A correct diagnosis might be obtained when typical imaging findings present even without histological confirmation.

Imaging findings of biliary hamartomas

AIM: To evaluate the imaging findings of biliary hamartomas (von Meyenburg complexes, VMCs) and discuss the differential diagnosis with other related diseases.

METHODS: Imaging findings of biliary hamartomas on ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), MR cholangiopancreatography (MRCP)and hepatobiliary scintigraphy were retrospectively analyzed in six patients.

RESULTS: On ultrasound images, five of the six cases showed multiple small hyper- and hypo-echoic lesions with comet-tail echoes, especially when magnified by US with the usage of zoom function. In all the six cases, multiple tiny hypodense lesions less than 10 mm in diameter were revealed as scattered throughout the liver with no enhancement on CT. These tiny lesions were demonstrated to be hyper- and hypo-intensity on T2- and TI-weighed images, respectively, in three patients who underwent MRI examinations. MRCP was performed in two patients, and clearly showed multiple tiny irregular- and round-shaped hyper-intensity lesions. MRCP and hepatobiliary scintigraphy showed normal appearances of intra- and extra-hepatic bile ducts in two and one patients, respectively.

CONCLUSION: Imaging modalities are useful in the diagnosis and differential diagnosis of VMCs. A correct diagnosis might be obtained when typical imaging findings are present even without a histological confirmation.

Hepatic bile duct hamartomas (von Meyenburg Complexes): MR and MR cholangiography findings

Multiple bile duct hamartomas (MBDHs) of the liver, also known as von Meyenburg complexes, are easily confused with diffuse metastatic disease of the liver on US and CT. At present, histologic examination after tissue preevaluation is usually necessary for definite diagnosis. We report four cases in which the MR features, and especially the MR cholangiographic (MRC) findings, were highly suggestive for MBDH. Characteristic findings include multiple markedly hyperintense nodules on T2-weighted imaging, typically measuring <1.5 cm; no communication with the biliary tree; and irregular delineation of the lesions with no or slight rim enhancement following gadolinium administration.