Tumor seeding complicating radiofrequency ablation of hepatocellular carcinoma

A 77-year-old woman with cryptogenic cirrhosis presented with a 3 cm contrast enhancing mass in the lateral segment of the left hepatic lobe seen on triphasic computed tomographic (CT) examination of the abdomen. Her alpha fetoprotein (AFP) was 48.4 ng/ml (,6 ng/ml). An ultrasound guided transcutaneous single pass radiofrequency ablation (RFA) of the mass was performed without immediate complications. Seven months later the patient presented with upper abdominal pain. A repeat CT scan demonstrated a new lobulated contrast enhancing mass in the subcutaneous fat of the midline anterior abdominal wall (white arrow). A 3 cm hypodense area in the lateral segment of the left hepatic lobe (black arrow), consistent with the site of previous RFA, was also observed. The repeat serum AFP was now 999 ng/ml. The subcutaneous mass represents needle tract seeding complicating the RFA. RFA is a thermal treatment technique designed to produce localized tumor destruction. Its use is particularly attractive in high-risk operative candidates such as our elderly patient with a localized HCC in a cirrhotic liver. RFA can be performed percutaneously, laparoscopically or at the time of laparotomy. Treatment related complications occur in 10% of patients in most series and include pain, hemoperitoneum, capsular hematoma, pneumothorax, infection and portal thrombosis. Local tumor recurrence at the RFA site is infrequent (3.6%) [1]. Needle tract seeding, in up to 12.5% of cases, is now also recognized as a long-term complication of RFA [2]. This particular complication occurs predominantly in surface or immediate subcapsular lesions such as in this patient. Proposed explanations include the larger needles used in RFA compared with other forms of local therapy such as percutaneous ethanol injection. The J-hooks used in the multiple array RFA electrodes can also potentially pierce the capsule in peripheral tumors resulting in local seeding. This case highlights the risk of tumor seeding after RFA of subcapsular HCC.