Needle track seeding after radiofrequency ablation for hepatocellular carcinoma: prevalence, impact, and management challenge

Abstract

Neoplastic seeding may arise after radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). A low risk of seeding after RFA (0-1.1%) has been reported, which may rise up to 2.5% if ablation followed diagnostic biopsy. Needle track seeding presents with one or multiple rounded nodules along the needle track located within the peritoneum, along the abdominal muscles, which were penetrated by the needle, pleural surface, or in the subcutaneous and cutaneous tissues. The most widely used method for the assessment of seeding nodules is ultrasound (US), which usually displays hypoechoic nodules with intralesional vascularization. Fine needle aspiration biopsy of the nodule suspicious for malignant implant is mandatory to confirm the diagnosis and plan therapy. Wide surgical excision is the treatment of choice for neoplastic seeding. Thanks to early diagnosis and prompt treatment, development of needle track seeding is not likely to affect the long-term survival of patients.

Keywords: HCC; ablation; biopsy; liver; seeding.

Figure 1

Three months after RF ablation of a 2 cm HCC nodule in the left lobe, the follow-up US shows a 6 mm hypoechoic nodule (between markers) in the subcutaneous layer of the abdominal wall at the point of the previous insertion of the electrode needle. Note: Malignant HCC cells were shown at FNB. Abbreviations: RF, radiofrequency; US, ultrasound; HCC, hepatocellular carcinoma; FNB, fine needle biopsy.

Figure 2

Subcutaneous HCC seeding shows an intralesional vascular pole at color Doppler examination. Abbreviation: HCC, hepatocellular carcinoma.