Imaging presentation of biliary adenofibroma: A case report

BACKGROUND

Biliary adenofibroma (BF) is a rare benign epithelial tumor with the possibility of malignant transformation. Its main pathological feature is a well-defined cystic or honeycomb mass. BF has no specific clinical manifestations or laboratory and imaging findings; thus, it is easily misdiagnosed before surgery. This report describes a case in which biliary cystadenoma was misdiagnosed preoperatively and BF was diagnosed postoperatively. The imaging features, particularly the magnetic resonance imaging (MRI) features, were analyzed and summarized.

CASE SUMMARY

A 68-year-old Chinese man was admitted to our hospital with a 2-mo history of abdominal discomfort. Following admission to our hospital, laboratory examinations showed normal tumor marker concentrations and liver function. Hepatocellular carcinoma was considered after contrast-enhanced ultrasound examination. MRI suggested the possibility of cystadenoma of the bile duct. However, postoperative pathological examination confirmed the diagnosis of BF. No local recurrence was found 1 mo after surgery.

CONCLUSION

Our objective is to highlight the imaging diagnostic value of BF, especially on an MRI enhanced scan with gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid.

[Value of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid enhanced magnetic resonance imaging and diffusion-weighted MR imaging in predicting microvascular invasion in hepatocellular carcinoma and the prognostic significance]

Objective: To investigate the combined value of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) enhanced magnetic resonance imaging (MRI) and diffusion-weighted imaging (DWI) in predicting pathological microvascular invasion (pMVI) preoperatively, and to determine the relationship between prediction results and prognosis in hepatocellular carcinoma (HCC) patients. Methods: A total of 181 newly diagnosed HCC patients were enrolled in this study. Imaging characteristics and the apparent diffusion coefficient (ADC) value of DWI were analyzed. The differences of imaging characteristics and ADC values between different pMVI groups were analyzed.Multivariate logistic regression and receiver operating characteristic (ROC) curve were used to analyze the value for pMVI prediction by using significant parameters. The patients were grouped based on MRI predicted MVI (mrMVI), and the relationship between mrMVI and recurrence free survival time (RFS) was analyzed. Results: Fifty-one patients were pMVI positive and 130 patients were pMVI negative. The ADC value in pMVI positive group were (1.10±0.17)×10(-3) mm(2)/s, significantly lower than (1.27±0.22)×10(-3) mm(2)/s of pEMVI negative group (P<0.001). The incidence rates of incomplete enhancing "capsule" , non-smooth tumor margin, arterial peritumoral enhancement, mosaic architecture and peritumoral hypointensity on hepatobiliary phase (HBP) in pMVI positive group were significantly higher than those of negative group (all P<0.05). Multivariate logistic regression analysis showed that tumor margin, arterial peritumoral enhancement, peritumoral hypointensity on HBP and ADC value were independently associated with pMVI. ROC analysis showed that the area under curve, sensitivity and specificity of pMVI predicted by combined parameters were 0.830, 76.5% and 81.5%, respectively. The median RFS of mrMVI positive group was 23.6 months, significantly lower than 38.2 months of mrEMVI negative group (P=0.004). Conclusion: Tumor margin, arterial peritumoral enhancement, peritumoral hypointensity on HBP and ADC value are independent predictors of pMVI in HCC, and mrMVI is related with RFS.

Direct-Acting Antiviral Agents Reduce the Risk of Malignant Transformation of Hepatobiliary Phase-Hypointense Nodule without Arterial Phase Hyperenhancement to Hepatocellular Carcinoma on Gd-EOB-DPTA-Enhanced Imaging in the Hepatitis C Virus-Infected Liver

BACKGROUND AND AIMS

Hepatobiliary phase-hypointense nodules without arterial phase hyperenhancement (HHNs without APHE) on gadolinium-ethoxybenzyl-diethylenetriamine-enhanced magnetic resonance imaging (Gd-EOB-DTPA-enhanced MRI) are considered to be dysplastic nodules or early hepatocellular carcinoma (HCC) and have high risk of undergoing malignant transformation and progression to hypervascular HCC. The aim of this study was to evaluate the clinical outcome of HHNs without APHE diagnosed by Gd-EOB-DTPA-enhanced MRI before the eradication of HCV by direct-acting antiviral agents (DAAs).

METHODS

We retrospectively investigated 221 consecutive patients with HCV infection who were treated with DAAs. Thirty patients with 65 HHNs without APHE were enrolled in a sustained virologic response (SVR) cohort and 22 with 43 HHNs without APHE who did not receive DAAs or had failed HCV eradication therapy were enrolled in a non-SVR cohort. Fifty-seven percent of patients in the SVR group and 64% of those in the non-SVR group had a history of HCC. The primary endpoint of this study was the development of hypervascular HCC from HHNs without APHE detected on imaging. The cumulative incidence and relative risk of progression to hypervascular HCC in relation to clinical characteristics were compared between the two cohorts.

RESULTS

The 2-year cumulative incidence of progression to hypervascular HCC was 8.5 and 21.9% in the SVR and non-SVR cohorts, respectively. There was a significant reduction in progression of HHNs without APHE to HCC after the eradication of HCV (p = 0.022, log-rank test). Multivariate Cox regression analysis identified hyperintensity on T2-weighted images (relative risk 14.699, p < 0.001) and achieving SVR (relative risk 0.290, p = 0.043) as independent factors associated with the risk of HCC. During follow-up, 6 (9.2%) of the HHNs without APHE in the SVR cohort became undetectable on hepatocyte-phase images.

CONCLUSIONS

Eradication of HCV by DAAs could reduce the hypervascularization rate of HHNs without APHE, and some of these nodules disappeared.

Staging of liver fibrosis using Gd-EOB-DTPA and Gd-BOPTA enhanced magnetic resonance imaging

The severity of cirrhosis is closely related to its clinical treatment. Therefore, it is important to stage liver fibrosis accurately. Although liver biopsy can accurately stage the degree of cirrhosis, it has certain limitations in clinical application because of its invasive nature. Magnetic resonance imaging (MRI) has been used in the diagnosis of liver diseases. In recent years, two new contrast agents, gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) and gadobenate dimeglumine (Gd-BOPTA), have been successfully used for noninvasive liver imaging. They can be used for liver fibrosis staging and assessment of liver function. Cirrhotic patients with different liver function levels have a statistical difference in the liver parenchyma enhancement after giving contrast agents. This article briefly summarizes the progress of Gd-EOB-DTPA and Gd-BOPTA enhanced MRI in staging liver fibrosis stage.

3D T2-weighted and Gd-EOB-DTPA-enhanced 3D T1-weighted MR cholangiography for evaluation of biliary anatomy in living liver donors

PURPOSE

To investigate whether the addition of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced 3D T1-weighted MR cholangiography (T1w-MRC) to 3D T2-weighted MRC (T2w-MRC) improves the confidence and diagnostic accuracy of biliary anatomy in living liver donors.

METHODS

Two abdominal radiologists retrospectively and independently reviewed pre-operative MR studies in 58 consecutive living liver donors. The second-order bile duct visualization on T1w- and T2w-MRC images was rated on a 4-point scale. The readers also independently recorded the biliary anatomy and their diagnostic confidence using (1) combined T1w- and T2w-MRC, and (2) T2w-MRC. In the 23 right lobe donors, the biliary anatomy at imaging and the imaging-predicted number of duct orifices at surgery were compared to intra-operative findings.

RESULTS

T1w-MRC had a higher proportion of excellent visualization than T2w-MRC, 66% vs. 45% for reader 1 and 60% vs. 31% for reader 2. The median confidence score for biliary anatomy diagnosis was significantly higher with combined T1w- and T2w-MRC than T2w-MRC alone for both readers (Reader 1: 3 vs. 2, p < 0.001; Reader 2: 3 vs. 1, p < 0.001). Compared to intra-operative findings, the accuracy of imaging-predicted number of duct orifices using combined T1w-and T2w-MRC was significantly higher than that using T2w-MRC alone (p = 0.034 for reader 1, p = 0.0082 for reader 2).

CONCLUSION

The addition of Gd-EOB-DTPA-enhanced 3D T1w-MRC to 3D T2w-MRC improves second-order bile duct visualization and increases the confidence in biliary anatomy diagnosis and the accuracy in the imaging-predicted number of duct orifices acquired during right lobe harvesting.