Intratumoral pseudoaneurysms in hepatocellular carcinoma: do they occur de novo without any prior intervention? A tertiary care center experience of 6 years

A case of hepatocellular carcinoma with pseudoaneurysm formation upon lenvatinib administration

A 79-year-old man received treatment for multiple intrahepatic hepatocellular carcinoma with atezolizumab + bevacizumab. However, he developed lower back pain attributed to spinal metastases upon tumor enlargement; thus, he was admitted to our hospital for a change from atezolizumab + bevacizumab to lenvatinib and radiation therapy for the spinal metastases. On the 11th day after starting lenvatinib treatment, a pulsatile aneurysm appeared in the tumor, detected using abdominal ultrasonography Micro B-flow imaging, which visualized blood flow at a high frame rate; this was diagnosed as a pseudoaneurysm. The patient refused treatment for the pseudoaneurysm; therefore, he was carefully followed up. Fortunately, the pseudoaneurysm disappeared on the 17th day. One month later, the tumor had become completely necrotic. Lenvatinib demonstrated effectiveness in inhibiting angiogenesis in the tumor, as evidenced by a decrease in tumor blood flow. This case report suggests that pseudoaneurysm formation within the tumor occurs early after the administration of lenvatinib; thus, clinicians must be aware of the potential risk of pseudoaneurysm rupture.

Typical and Atypical Imaging Findings of Hepatocellular Carcinoma on Multiphasic MDCT Scan in Histologically Proved Cases

Objective The purpose of this study was to find out the incidence of typical and atypical radiological imaging findings of hepatocellular carcinoma (HCC) on multiphase multidetector computed tomography (MDCT) scans in histologically proven cases.

Materials and Methods A multiphase computed tomography study of 73 patients with histologically proven HCC was evaluated by a radiologist. Our multiphasic protocol was composed of precontrast, arterial, portal, and delayed venous phases. The reviewers analyzed the CT images for tumor size, enhancement patterns of HCC in different phases, relative timing of washout, internal cystic changes, and presence of dysmorphic intratumoral vessel aneurysms or arteriovenous shunt.

Results Most of the cases (95.9%) showed typical enhancement patterns in MDCT, i.e., enhancements in the arterial phase with the portal or delayed venous phase contrast washout. Three cases (4.9%) out of 73 HCC showed enhancements in the portal phase and washout in the delayed venous phase. Seven cases out of total 73 HCC (9.5%) patients showed heterogeneous enhancements in both arterial and portal phases and contrast washout in the delayed venous phase. Venous thrombosis was noted in about 44 cases (60%) out of total 73 patients, in which portal vein thrombosis was more common than hepatic veins/inferior vena cava.

Conclusion Most of the HCC show typical enhancement patterns, i.e., heterogeneous enhancements in the arterial phase and washout in the portal venous phase when we use MDCT. These findings are higher than those described previously. However, in our study, the main difference with MDCT was lower frequency of intratumoral pseudoaneurysm and bile duct invasion, and intratumoral fat and calcification (atypical character of HCC) were not found which were rare findings in previous study.

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.