Stratégie diagnostique devant une tumeur graisseuse des tissus mous de l'adulte

Benign tumors containing fat, in particular lipoma, are the most common soft tissue tumors. Liposarcoma, though much rarer, is the second most common soft tissue sarcoma. Image-based identification of the fatty nature of a soft tissue tumor is relatively easy. On the other hand, the distinction between a lipoma or its variants, and an atypical lipomatous tumor/well-differentiated liposarcoma can be much more challenging. However, this differentiation is fundamental to the prognosis and management of patients, and the radiologist must know the indications for biopsy. This consensus statement by a group of French experts, including those of the national sarcoma group, aims to answer frequently-asked questions about fatty tumors and to develop recommendations for the various specialists involved in their management. The first part of this article is devoted to a diagnostic algorithm for fat-containing, soft tissue masses discovered on MRI and/or CT. The second part focuses on recent advances that are evolving the diagnostic and therapeutic strategy for these tumors.