Myxofibrosarcoma-Like Pleomorphic Liposarcoma

Abstract Pleomorphic liposarcoma is the least common subtype of liposarcoma, accounting for less than 5% of cases, but is important to distinguish from other liposarcoma subtypes due to a significantly worse prognosis closer to that of a high-grade sarcoma. A substantial proportion of cases demonstrate histologic features overlapping with myxofibrosarcoma, except for the presence of diagnostic pleomorphic lipoblasts. These lipoblasts are essential to the diagnosis of pleomorphic liposarcoma, in contrast to the other subtypes of liposarcoma, but can be highly focal/variable in extent, mandating extensive gross sampling and thorough histologic examination and representing a pitfall in diagnosis particularly in small biopsies. Awareness of the less common histologic patterns of this uncommon entity will hopefully facilitate correct diagnosis.