Fig. 2: Histopathologic features of myxoid pleomorphic liposarcoma (MPLPS).

MPLPS is characterized by chicken wire-like vasculature seen in myxoid/round cell liposarcoma (MRLPS) admixed with univacuolated signet ring-like lipoblasts in MRLPS (A) or multivacuolated pleomorphic lipoblasts typically seen in PLPS (B, C) (A case 3, 100×. B case 7: 200×. C case 2: 200×). In some cases, the pleomorphic lipoblasts demonstrate foamy cytoplasm (xanthoma-like) (D case 8, 400×. E case 6, 200×). Classic, “pulmonary edema”-like cystic spaces characteristic of MRLPS could be seen in MPLPS (F case 5, 100×). Occasionally, paucicellular lipogenic areas reminiscent of well-differentiated liposarcoma could be seen (G case 3, 100×). Case 1 also demonstrated lipogenic but highly cellular areas with high-grade nuclear atypia (H 200×) that transitions abruptly to non-lipogenic and cellular, undifferentiated pleomorphic sarcoma-like areas (I 200×), suggesting a “dedifferentiated” process.