What should be done if a cryoablation of renal cell carcinoma (RCC) is performed successfully but follow-up imaging demonstrates a possible pseudoaneurysm? Here, Nassir Rostambeigi (Mallinckrodt Institute of Radiology, St Louis, USA) shares details of a case in an attempt to answer this question.
Renal cryoablation is a well-established technique for treating renal masses, offering comparable outcomes to partial nephrectomy while minimising morbidity. However, careful consideration of its safety profile, including both common and rare adverse events, is essential for care providers.
This case report highlights a rare and significant scenario. An 81-year-old woman with stage three chronic kidney disease initially presented with a left renal mass measuring 2.7cm. Follow-up imaging revealed an increase to 3.1cm, prompting a multidisciplinary decision to proceed with computed-tomography (CT)- guided biopsy and cryoablation. The procedure was successful, but subsequent imaging uncovered a suspicious arterially enhancing lesion, initially suspected to be a pseudoaneurysm.
Detailed evaluation of contrast-enhanced CT phases revealed a round structure at the ablation site, exhibiting contrast uptake similar to the aorta—raising concerns about a pseudoaneurysm. Then, coil embolization was performed to treat this suspected pseudoaneurysm, which initially seemed effective. However, persistent and recurrent enhancement on CT scans soon raised the possibility of residual or recurrent renal cell carcinoma.
Further investigation involved ultrasound evaluation, which identified the lesion as a solid mass without internal vascular pulsatility, ruling out a pseudoaneurysm. To confirm the diagnosis and for planning, an angiogram was performed, and, using lipiodol, the lesion was stained to enhance visualisation under CT guidance. Then, a percutaneous biopsy followed by cryoablation of the focal recurrence, was then carried out under CT guidance.
Pathological examination confirmed recurrent clear-cell renal cell carcinoma. The patient has maintained baseline urinary function and, 30 months after repeat cryoablation, remains free of recurrent disease.
This case underscores the importance of thorough post-ablation imaging, as recurrence can mimic vascular abnormalities like pseudoaneurysms. Careful evaluation with ultrasound or magnetic resonance imaging (MRI) is crucial in differentiating tumour recurrence from benign post-procedural changes, ensuring timely and appropriate intervention is provided.
Nassir Rostambeigi is an interventional radiologist at the Mallinckrodt Institute of Radiology, in St Louis, USA.
