Intratumoral pseudoaneurysm within a liver metastasis of gastric cancer: a case report.

BACKGROUND: Intrahepatic artery pseudoaneurysms are mostly iatrogenic and result from hepatobiliary interventions. The incidence of intrahepatic artery pseudoaneurysms within liver tumors without prior intervention is extremely rare. We presented herein the first report of a case of an intratumoral pseudoaneurysm within a liver metastasis of gastric cancer without any prior intervention during chemotherapy. CASE PRESENTATION: A 59-year-old male patient underwent a distal gastrectomy and D2 lymph node dissection for gastric cancer. He was treated in the emergency room for right abdominal pain following the 4th cycle of nivolumab administration as second-line chemotherapy after adjuvant chemotherapy with S-1 and first-line chemotherapy for a liver metastasis of gastric cancer with ramucirumab plus paclitaxel. CT showed a 72-mm metastatic liver tumor containing a 9-mm pseudoaneurysm and fluid collection around the hepatic edge. Intrahepatic artery pseudoaneurysm within the metastatic liver tumor was diagnosed, with the surrounding fluid indicating potential, active bleeding. An emergency angiography confirmed the presence of a pseudoaneurysm in the intrahepatic artery, which was embolized using microcoils. The contributory causes of the intratumoral pseudoaneurysm were assumed to be the following: (1) tumor necrosis leading to encasement, erosion of the vessel wall, and subsequent arterial wall weakening; and (2) inhibition of vascular endothelial growth by ramucirumab resulting in a vessel wall breach and pseudoaneurysm formation. CONCLUSION: It is necessary to recognize that pseudoaneurysms can arise within a metastatic liver tumor during chemotherapy.

Percutaneous radiofrequency ablation and transcatheter arterial chemoembolization for hypervascular hepatocellular carcinoma: rate and risk factors for local recurrence.

PURPOSE: To analyze local recurrence-free rates and risk factors for recurrence following percutaneous radiofrequency ablation (RFA) or transcatheter arterial chemoembolization (TACE) for hypervascular hepatocellular carcinoma (HCC). METHODS: One hundred and nine nodules treated by RFA and 173 nodules treated by TACE were included. Hypovascular nodules were excluded from this study. Overall local recurrence-free rates of each treatment group were calculated using the Kaplan-Meier method. The independent risk factors of local recurrence and the hazard ratios were analyzed using Cox's proportional-hazards regression model. Based on the results of multivariate analyses, we classified HCC nodules into four subgroups: central nodules < or =2 cm or >2 cm and peripheral nodules < or =2 cm or >2 cm. The local recurrence-free rates of these subgroups for each treatment were also calculated. RESULTS: The overall local recurrence-free rate was significantly higher in the RFA group than in the TACE group (p = 0.013). The 24-month local recurrence-free rates in the RFA and TACE groups were 60.0% and 48.9%, respectively. In the RFA group, the only significant risk factor for recurrence was tumor size >2 cm in greatest dimension. In the TACE group, a central location was the only significant risk factor for recurrence. In central nodules that were < or =2 cm, the local recurrence-free rate was significantly higher in the RFA group than in the TACE group (p < 0.001). In the remaining three groups, there was no significant difference in local recurrence-free rate between the two treatment methods. CONCLUSION: A tumor diameter of >2 cm was the only independent risk factor for local recurrence in RFA treatment, and a central location was the only independent risk factor in TACE treatment. Central lesions measuring < or =2 cm should be treated by RFA.

[Evaluation of strongly hyperintense area in breast lesions on fat-suppressed T2-weighted images correlated with histopathology].

The purpose of this study was to correlate strongly hyperintense areas(SHI) in breast lesions on FS-T2WI with histopathology and to evaluate the usefulness of the distribution patterns of SHI in the differentiation of benign and malignant breast lesions. MR imaging with pathological correlation was available in 157 breast lesions of 153 patients. The distribution patterns of SHI were classified into seven types. SHI on FS-T2WI was identified in 36 of 157 breast lesions. The irregular and inhomogenous types corresponded to various histological features and were only seen in malignant lesions. The central type corresponded to central necrosis and was only seen in 2 solid-tubular carcinomas. The crescent type corresponded to peripheral fluid collection in the intracystic tumor. The septal type corresponded to fibromyxoid stroma with fibrous septations in the lesions except for one cavernous hemangioma, and was only seen in benign lesions. The smooth type corresponded to mucinous pool, fibromyxoid stroma, and ductal dilatation and did not contribute to differentiation between benign and malignant lesions only on FS-T2WI. SHI in breast lesions on FS-T2WI pathologically corresponded to mucin, fibromyxoid change, necrosis, and ductal dilatation. Evaluation of patterns of SHI is useful in differentiating between benign and malignant lesions.