This is a single-center, Phase II study including only patients on whom a decision to conduct radiofrequency ablation (RFA) has already been made. The primary objective of this study assess if quality of life was improved by RFA as assessed at baseline, 3 and potentially 6 and 12 months following RFA for the benign lesions.

RFA is an imaging guided percutaneous or intra-operative procedure that uses a probe on the end of a sharp needle that is inserted directly into the tumor. The tumor is ablated by heating the probe (using an electrical current alternating at radio frequency) which raises the temperature of the tumor potentially causing irreversible cell death.

RF ablation is an alternative for local tumor control when other treatments (surgery, radiotherapy or chemotherapy) are not feasible (less effective or at higher risk). Thermal ablation at times is the only remaining alternative for patient cure, prolonged survival or palliation. Cryotherapy, and microwave, laser and focused ultrasound are alternative thermal ablation techniques used in adults but there has been no experience in children with these alternative methods.

To be eligible for this study, patients must have acquired lesions at < 21 years of age (central nervous system lesions are excluded from this study). Study participants will have the RFA procedure performed at Seattle Children's and will have follow-up evaluations at various time points post-RFA.