Radiologically identifiable intratumoral portal vein in intrahepatic cholangiomas: a diagnostic pitfall

Primary hepatic diffuse large B-cell lymphoma presenting unusual imaging features

Primary hepatic lymphomas are frequently misdiagnosed, due to their rarity and non-specific clinical manifestations. As these tumors can be successfully treated with chemotherapy and/or radiotherapy, early recognition on imaging is essential to avoid unnecessary surgery. We report a case of primary hepatic lymphoma in a 73-year-old woman presenting with a 1-week history of persistent fever and elevated hepatobiliary enzymes. Ultrasound showed a hypoechoic hepatic mass in the anterior segment. Dynamic contrast-enhanced computed tomography (CT) revealed an ill-defined solitary mass showing peripherally dominant slight-to-moderate enhancement contrasting with a hypovascular central area. On magnetic resonance imaging, the mass showed moderate hyperintensity on T2-weighted imaging, hypointensity on T1-weighted imaging, doughnut-like hyperintensity on diffusion-weighted imaging, and an obviously low apparent diffusion coefficient (ADC). The pattern of enhancement resembled that of CT. Neither calcification nor any fat component was observed. Doughnut-like accumulation was seen on ¹⁸F-fluorodeoxyglucose (FDG)-positron emission tomography/CT without other FDG-avid lesions. Imaging findings suggested the possibility of cholangiocellular carcinoma, but the low ADC and extremely high FDG accumulation were suggestive of malignant lymphoma, and diffuse large B-cell lymphoma was pathologically confirmed from percutaneous biopsy. The mass disappeared after radiochemotherapy, and no recurrence has been observed for 3 years.

A case of focal confluent hepatic fibrosis in the patient with hepatitis C virus-related liver cirrhosis: a mimic of cholangiolocellular carcinoma

During routine ultrasound examination, a hyperechoic mass was detected in the anterior segment of the liver in an 80-year-old woman with hepatitis C virus-related cirrhosis. Computed tomography and magnetic resonance imaging findings suggested a malignant tumor with abundant fibrous stroma, similar to cholangiolocellular carcinoma. However, subsequent partial hepatectomy revealed a mass characterized by abundant fibrosis without tumor cells, dilated blood vessels, and marginal ductular reaction. Accordingly, focal confluent fibrosis was diagnosed. Generally, the diagnosis of focal confluent fibrosis is straightforward because of its well-established imaging characteristics. However, its differentiation from a malignant tumor can occasionally be difficult because of variation in presentation depending on the amount of fibrous stroma and the degree of inflammatory cell infiltration. In the present case, diagnosis was difficult because the lesion was more localized than usual, presenting a mass-like shape, and there was obvious hyperintensity on T2-weighted imaging and ring-shaped hyperintensity on diffusion-weighted imaging. Moreover, hepatic capsular retraction was indistinct, which can be one of the key findings of focal confluent fibrosis. When a hepatic mass is associated with a fibrous lesion, focal confluent fibrosis should be considered in the differential diagnosis, even though the lesion is associated with several atypical findings.

Hepatic sarcoidosis with atypical radiological manifestations: A case report

Sarcoidosis is a multisystemic inflammatory disease of unknown origin characterized by the formation of noncaseating granulomas and accumulation of inflammatory cells. Sarcoidosis most commonly affects the lungs and lymphoid system. However, the liver can also be involved in 50%-65% of cases. On magnetic resonance imaging, sarcoidosis lesions usually present as hypointense lesions on all sequences. However, we present a rare case of nodular liver sarcoidosis presenting with T2 hyperintense lesions. In addition, while most cases of hepatic nodular sarcoidosis present with multiple small hepatic nodules, liver masses of our case are larger than usual. Moreover, this case suggested that when intact vascular structures penetrating liver nodular lesions are observed as in the current case, liver sarcoidosis can be included in a list of differential diagnosis.

Intrahepatic Cholangiolocellular and Cholangiocellular Carcinoma - Differences in the 18F-FDG PET/CT Findings

Cholangiolocellular carcinoma is a minor primary cancerous tumor of the liver and its coexistence with intrahepatic cholangiocarcinoma in the liver is rare. We herein report a case of concurrent cholangiolocellular carcinoma and intrahepatic cholangiocarcinoma in the liver, in addition to a rectal G1 neuroendocrine tumor, a so-called carcinoid. The intrahepatic tumors showed a different uptake in the ¹⁸F-fluoro-2-deoxyglucose (FDG) positron-emission tomography (PET)/computed tomography (CT) findings. In addition to conventional dynamic contrast-enhanced CT, we concluded that FDG PET/CT could therefore be a helpful modality to identify the properties of both cholangiolocellular carcinoma and intrahepatic cholangiocarcinoma.

B-flow imaging of vascular structure for the diagnosis of liver tumor

PURPOSE

B-flow is a non-Doppler-based technology for visualizing blood flow and has a high spatial resolution. The aim of this study is to evaluate the blood flow information of liver tumors using B-flow in comparison with color Doppler sonography (CDS).

METHODS

Seventy-nine patients with 82 hepatic nodules were studied using B-flow and CDS. The study group included 45 HCC nodules, 23 liver metastasis nodules, four intrahepatic cholangiocarcinomas (ICC), and 13 hemangiomas. The visualized vascularity and morphological findings of the hepatic tumor vessel were evaluated.

RESULTS

B-flow showed multiple vessels in 48 nodules (58.5 %) and a single vessel in 13 nodules (15.9 %). CDS showed multiple vessels in 44 nodules (53.7 %) and a single vessel in 23 nodules (28.0 %). Multivariate analysis showed basket pattern was significant for HCC (OR 49.263; p = 0.0002), and penetrating vessel was significant for liver metastasis or ICC (OR 14.545; p < 0.0001).

CONCLUSION

B-flow detects hepatic tumor blood flow with sensitivity as high as that of CDS. Vascular structure information obtained using B-flow could be potentially used to diagnose liver tumors.

Imaging of cholangiolocellular carcinoma of the liver

AIM

Cholangiolocellular carcinoma (CoCC) is currently considered to originate from hepatic progenitor cells. The purpose of this study was to evaluate the imaging features of cholangiolocellular carcinoma of the liver.

MATERIALS AND METHODS

Five cases of surgically resected cases of CoCC from 4 institutions were retrospectively evaluated. All of the five patients underwent contrast-enhanced dynamic CT. MRI and angio-CT including CT during arterioportography (CTAP) and CT during hepatic arteriography were performed in 3 and 2 patients, respectively. Histological evaluation was also performed and was correlated with radiographic findings.

RESULTS

On dynamic CT or MRI, the lesions presented hypervascular tumors with delayed washout in 2 cases and in the other 3 cases, the lesions showed peripheral enhancement with concentric delayed filling. On CTAP, the continued existence of portal veins or tiny spots of portal flow was identified in the tumors. Fibrous capsule or tumor necrosis was not observed.

CONCLUSION

CoCC tumors have the dual imaging characteristics of hepatocellular carcinoma and cholangiocarcinoma. The absence of a fibrous capsule, the absence of tumor necrosis, peripheral location within the liver, and the presence of portal venous penetration within the tumor also appear to be characteristic features.