Skin Atypical Lipomatous Tumor

**Semantic type:** Neoplastic Process

**Definition:** A rare, locally aggressive cutaneous mesenchymal neoplasm characterized by the presence of an adipocytic proliferation exhibiting at least focal nuclear atypia in both adipocytes and stromal cells. Amplification of MDM2 and/or CDK4 is almost always present.

**Synonyms:** - Skin ALT - Skin ALT/WDLPS - Skin Atypical Lipomatous Tumor/Well Differentiated Liposarcoma - Skin Atypical Lipomatous Tumor/Well-Differentiated Liposarcoma