Liposarcoma: New entities and evolving concepts

摘要: Liposarcoma is the most common soft tissue sarcoma and accounts for approximately 20% of all mesenchymal malignancies. In last decade, results several studies have led to delineation new variants as well introduction concepts, mainly a result fruitful interactions between genetics pathology. Spindle cell liposarcoma represents an uncommon variant well-differentiated liposarcoma. It tends occur in adults often involves subcutaneous tissue. However, from observation larger number cases, anatomic distribution spindle seems be comparable that other subtypes. recur locally may dedifferentiate. Morphologically it composed fairly bland neural-like proliferation set fibrous and/or myxoid background associated with atypical lipomatous component. Great debate has been generated by term lipoma emphasize fact shows risk local recurrence but no potential metastasis. our opinion should considered synonyms describe lesions identical both morphologically kayotypically. Dedifferentiated distinct type which transition low-grade high-grade nonlipogenic morphology within observed. The usually occurs abrupt fashion; however, rare cases can more gradual. Recently, also proposed dedifferentiated further classified into low high grade. rarely exhibits heterologous (most myoid) differentiation. A peculiar “neural-like whorling pattern” dedifferentiation described recently. Surprisingly, clinical outcome less aggressive pleomorphic sarcomas genetic molecular data exist partially justify such discrepancy. Myxoid round liposarcoma, even if still World Health Organization two subtypes, share morphologic features. Lesions combining patterns are very frequent wide agreement exists considering counterpart Furthermore, same characteristic chromosome change. Albeit rare, recently shown indeed primary skin lesion. presents clinically dome-shaped or polypoid lesion that, histologically, frequently features carries comparatively good prognosis. Considering currently available data, logical classification three main groups: (1) (including adipocytic, sclerosing, inflammatory, spindle-cell, variants), characterized ring long markers chromosomes derived arm 12; (2) (poorly differentiated myxoid) reciprocal translocation t(12;16)(q13;p11); (3) complex karyotypes. Ann Diagn Pathol 4:252-266, 2000.