Liposarcoma, light micrograph. Liposarcoma is one of the most common sarcomas of adulthood. It arises from fat in deep soft tissues of the extremities and retroperitoneum. The patients are usually in their sixth or seventh decades of life. Histologically, liposarcomas are subdivided into well-differentiated, myxoid and pleomorphic subtypes. This image shows myxoid liposarcoma. It bears resemblance to developing foetal fat and consists predominantly of fusiform and round cells in a background of abundant bluish myxoid matrix containing a network of delicate capillaries. Most myxoid liposarcomas contain a reciprocal translocation involving chromosomes 12 and 16; t(12;16)(q13;p11) resulting in fusion of DDIT3 gene on chromosome 12 with the FUS gene on chromosome 16. Magnification: x400.