Waters R, Horvai A, Greipp P, et al. - A total of 116 cases of atypical lipomatous tumor (ALT)/well-differentiated liposarcoma (WDL) (n = 75) and de-differentiated liposarcoma (DDLPS) (n = 41) were recognized, representing fewer than 5% of these tumors noticed in order to understand more precisely the clinicopathological characteristics of these tumors in younger individuals. In individuals aged ≤ 40 years, the occurrence of ALT/WDL and DDLPS were rare, nevertheless, in elderly people, it showed comparable morphological characteristics to its counterparts along with the potential for heterologous and homologous de-differentiation in the latter. However there were a limited number of cases, tumors arising in the head and neck showed high rates of adverse incidents, suggesting more relevance of WDL classification vs ALT classification.