• Subject (male or female) with extra-peritoneal desmoid tumor (confirmed by prior biopsy by an experienced pathologist within the RRePS network)

• 13 years of age or older

• Measurable viable tumor (according to the mRECIST criteria using MRI. The baseline MRI imaging is mandatory in the 2 months prior to treatment initiation (D0).

• Progressive disease (according to the mRECIST criteria) after the watchful waiting period or significant increase in symptoms requiring an active therapy, as advised in a multidisciplinary sarcoma tumor board

• Tumor deemed accessible for cryoablation procedure by the operator in a type I center. (In pediatric cases, a careful site tumor analysis will be performed with interventional radiologist to ensure for limited consequence of cryoablation in pediatric patients especially regarding growth plates).

• 100 % of destruction of the tumor achievable in one procedure of cryoablation with 1cm security margin according to assessment by referral center (type 1) for cryoablation

• ECOG performance status 0-2 at inclusion visit

• Biological and hematological parameters (neutrophils ≥ 1,5.109/L ; platelet count ≥ 100.109/L ; no significant hemostatic abnormalities) in the 4 weeks prior to treatment initiation (D0)

• Subject able to understand the objectives and risks of the research and to give dated and signed informed consent. For minors, the consent of the 2 parents must be obtained.

• Subject affiliated to a social health insurance plan

• For a woman of childbearing age: negative blood pregnancy test at screening/inclusion visit

• Subject agreeing to use a contraceptive method: