Subcutaneous Tumor Tract Seeding After Percutaneous Ablation for Clear Cell Renal Cell Carcinoma: A Case Report and...

Background and Clinical Significance: Percutaneous ablation is an increasingly used nephron-sparing treatment for small renal masses (SRMs). Although generally considered safe, tumor seeding along the applicator tract is rare (<0.1%) and may be underreported. This study reviews the existing literature to synthesize patterns, potential risk factors, and clinical presentation of this complication following percutaneous thermal ablation of renal cell carcinoma (RCC). Case Presentation: We report the case of an 84-year-old man who developed late subcutaneous abdominal-wall tumor seeding more than ten years after nephron-sparing surgery for a T1a renal mass and following three sessions of percutaneous cryo- and microwave ablation for recurrent clear-cell renal cell carcinoma (ccRCC). The lesion was surgically excised, and histology confirmed ccRCC with negative margins. A descriptive literature review was conducted using PubMed and ScienceDirect to identify English-language case reports and case series (CS) documenting tumor seeding after RCC percutaneous ablation. Eight studies involving nine patients met the inclusion criteria. The median age was 66 years (interquartile range [IQR] 64-74; range 47-84). The median follow-up duration was 11 months (IQR, 4.5-18.5; range 3-60), and the median interval to tumor seeding was 11 months (IQR, 6-18.5; range 3-60). Management included surgical excision (50%), repeat cryoablation (25%), and systemic therapy or supportive care (25%). Conclusions: Tumor tract seeding following percutaneous ablation for RCC is rare, with variable latency and presentation. Procedural factors such as the absence of tract ablation, multiple probe passes, and intra-procedural biopsy may increase risk. Awareness of this complication and long-term surveillance should be incorporated into follow-up protocols. Despite this risk, percutaneous ablation remains a safe and effective option for appropriately selected patients.