Pathology: pleomorphic liposarcoma

Pleomorphic liposarcoma

• Sheets of adipocytes admixed with spindle cells

• Clear-eosinophilic cytoplasm

• Round-ovoid, hyperchromatic, and pleomorphic nuclei; mitotic activity conspicuous

• Pleomorphic lipoblasts interspersed

• Necrosis often present

• FISH: MDM2 non-amplified

Pleomorphic liposarcoma

• Sheets of adipocytes admixed with epithelioid cells

• Clear-eosinophilic cytoplasm

• Round-ovoid, hyperchromatic, and pleomorphic nuclei; mitotic activity conspicuous

• Pleomorphic lipoblasts interspersed

• Necrosis often present

• FISH: MDM2 non-amplified

Pleomorphic liposarcoma

• Sheets of adipocytes admixed with spindle cells

• Clear-eosinophilic cytoplasm

• Round-ovoid, hyperchromatic, and pleomorphic nuclei; mitotic activity conspicuous

• Pleomorphic lipoblasts interspersed

• Necrosis often present

• FISH: MDM2 non-amplified

Pleomorphic liposarcoma

• Sheets of adipocytes admixed with polygonal cells

• Clear-eosinophilic cytoplasm

• Round-ovoid, hyperchromatic, and pleomorphic nuclei; mitotic activity conspicuous

• Pleomorphic lipoblasts interspersed

• Necrosis often present

• FISH: MDM2 non-amplified

Pleomorphic liposarcoma

• Sheets of adipocytes admixed with spindle cells

• Clear-eosinophilic cytoplasm

• Round-ovoid, hyperchromatic, and pleomorphic nuclei; mitotic activity conspicuous

• Pleomorphic lipoblasts interspersed

• Necrosis often present

• FISH: MDM2 non-amplified

Pleomorphic liposarcoma

• Sheets of polygonal cells

• Clear-eosinophilic and vacuolated cytoplasm

• Round-ovoid, hyperchromatic, and pleomorphic nuclei; occasional mitotic activity

• IHC: negative for MDM2 and CDK4 (not shown)

Pleomorphic liposarcoma

• Sheets of polygonal cells with peritheliomatous pattern

• Eosinophilic and vacuolated cytoplasm

• Round-ovoid, hyperchromatic, and pleomorphic nuclei; occasional mitotic activity

• Abundant necrosis

• FISH: MDM2 non-amplified

Pleomorphic liposarcoma

• Sheets of epithelioid-spindle cells

• Eosinophilic cytoplasm

• Round-ovoid, hyperchromatic, and pleomorphic nuclei; mitotic activity conspicuous

• Sheets of pleomorphic lipoblasts 

• Necrosis often present

• FISH: MDM2 non-amplified

Pleomorphic liposarcoma

• Fascicles of epithelioid-spindle cells

• Abundant eosinophilic cytoplasm

• Round-ovoid, hyperchromatic, and pleomorphic nuclei; mitotic activity conspicuous

• Focal myxoid stroma; interspersed nests of pleomorphic lipoblast-like cells 

• FISH: MDM2 non-amplified

(reasonable to wonder: is this a discrete entity, or perhaps heterologous adipocytic differentiation in myxofibrosarcoma, or another high grade sarcoma?)