Pathology: myxoid pleomorphic liposarcoma

Hypocellular spindle-stellate cell fascicles, with admixed adipocytes

Spindle-stellate cells have eosinophilic cytoplasm with delicate processes; nuclei are ovoid and hyperchromatic with moderate pleomorphism

Adipocytes have abundant clear cytoplasm with frequent multivacuolation; nuclei are hyperchromatic and scalloped, with moderate pleomorphism

Interspersed there is abundant myxoid stroma; prominent arcing and thick-walled vasculature

IHC: CD34

FISH: MDM2 non-amplified; RNA-seq: negative

Variably cellular sheets of stellate-polygonal cells, with admixed adipocytes

Stellate-polygonal cells have eosinophilic cytoplasm with delicate processes; nuclei are round-ovoid and hyperchromatic with moderate pleomorphism

Adipocytes are variably sized with abundant clear cytoplasm and frequent muclevacuolation; nuclei are hyperchromatic and scalloped, with moderate pleomorphism

Interspersed there is abundant myxoid stroma with a delicate arborizing vasculature

FISH: MDM2 non-amplified; RNA-seq: negative