Atypical lipoma: well-differentiated liposarcoma of the orbit with dedifferentiated areas.

Primary orbital liposarcoma is a very rare orbital tumor and dedifferentiation in the liposarcomas occurs rarely. Dedifferentiation is defined by development, in a well-differentiated tumor, of poorly differentiated, high-grade areas. The dedifferentiated liposarcomas (DDLS) have a better prognosis than pleomorphic sarcomas as a whole.