Primary angiosarcomas of the kidney are very rare but highly aggressive tumors showing poor prognosis. We present a case of primary renal angiosarcoma occurring in a 60-year-old man with left flank pain. CT images depicted a huge exophytic mass (14 cm in diameter) in the left kidney, exhibiting central extensive hemorrhage or necrosis without contrast enhancement. The mass showed centripetal peripheral nodular enhancement on dynamic contrast-enhanced CT images. We suggest its inclusion in the differential diagnosis of cases of hemorrhagic renal tumors with prominent vasculature.

We report a unique case of paravertebral arteriovenous fistulas (PVAVF) presenting with acute epidural hematoma produced by dilated venous pouch. The involved level in this patient makes this an extremely rare case. The main feeding artery was the right thyrocervical trunk and the dilated venous pouch was the posterior internal venous plexus around the upper thoracic spine. The etiology of this abnormal arteriovenous communication remains unclear. This case demonstrates that a venous ectasic pouch comprises important etiological angioarchitecture of radiculopathy and myelopathy in PVAVF.

To evaluate the feasibility, safety, and efficacy of radiofrequency (RF) ablation using an ablation system (arfa RF ABLATION SYSTEM Ⓡ ; Japan Lifeline Co. Ltd.) for treating solid tumors in various organs.Material and Methods: Between October 2019 and August 2021, 80 patients (29 women, 51 men; median age, 70.0 yr) underwent 107 RF ablation sessions using the ablation system to treat 151 tumors in the liver (n = 86), lung (n = 51), adrenal gland (n = 4), pleura (n = 4), bone (n = 3), lymph node (n = 2), and kidney (n = 1). The maximum tumor diameter was 2-40 mm (median, 11 mm). This study evaluated technical success (defined as the completion of planned RF ablation), technique efficacy (defined as the complete tumor ablation on follow-up images), and adverse events. Local tumor progression in 146 curatively treated malignant tumors was evaluated.Results: The technical success rate was 100% (107/107). Ablation zones in two tumors were insufficient. Therefore, the primary technique efficacy rate was 98.1% (105/107). Grade 3 hepatic infarction (1.6%, 1/64) and grade 4 pleuritis (3.4%, 1/29) occurred respectively after liver and lung RF ablation. During the median follow-up period of 10.2 months (Interquartile range, 4.2 and 16.4 months), local tumor progression developed in two tumors (1.4%, 2/146).Conclusions: The arfa RF ABLATION SYSTEM Ⓡ is a feasible, safe, and effective RF ablation device for managing solid tumors in various organs.

We report a 49-year-old male with castration-resistant prostate cancer (CRPC) with oligometastasis diagnosed by ¹¹C-choline positron emission tomography-computed tomography (PET/CT) and treated with target radiotherapy. In the diagnosis of CRPC (serum prostate-specific antigen [PSA] level of 6.53 ng/mL after maximum androgen blockade (MAB) therapy, high-dose brachytherapy, and external beam radiotherapy), ¹¹C-choline PET/CT detected one tiny obturator lymph node metastasis which fluorodeoxyglucose PET/CT could not detect. He underwent intensity-modulated radiation therapy and MAB was restarted. The PSA value decreased and reached nadir (0.091 ng/mL) after 6 months. The time to PSA progression was 10 months. The choline PET/CT finding and the corresponding local treatment could play an important role in the management sequence of oligoprogressive CRPC.

To clarify the utility of microballoon catheter in renal arterial ethanol embolization of renal angiomyolipoma (AML).Material and Methods: A total of 20 patients (15 women, 5 men) with median age of 45 years (39-60 years) underwent embolization to treat 22 AMLs. A mixture of ethanol and iodized oil was injected into the feeding arteries of 13 tumors using balloon occlusion (the balloon embolization group) with a microballoon catheter and 9 tumors without using balloon occlusion (the non-balloon embolization group). Changes in the maximum tumor diameter, tumor volume, and adverse events were evaluated.Result: The median baseline maximum tumor diameters and volumes were 6.3 cm and 61.4 cm 3 in the balloon embolization group, and 4.6 cm and 40.1 cm 3 in the non-balloon embolization group, respectively. Tumor enhancement disappeared on postembolization angiography in all cases. All tumors shrunk after embolization. There were no statistically significant differences in the percent decrease in the maximum tumor diameter and volume at 10-12 month between balloon occlusion group (31.5% and 67.9%) and control group (34.8% and 62.6%). Fever was significantly more frequent when balloon occlusion was used: 38% vs. 0% (p = 0.03). No major complication was observed in either patient group.Conclusions: Balloon occlusion may not affect tumor shrinkage when embolizing AMLs with a mixture of ethanol and lipiodol.