Pathology: dedifferentiated liposarcoma
Liposarcoma, "low-grade" dedifferentiation
Hypocellular; spindle-stellate cells arranged in loose fascicles
Dense eosinophilic cytoplasm
Ovoid and hyperchromatic nuclei with moderate pleomorphism; inconspicuous mitotic activity
Scattered epithelioid cells, some with multinucleation
Abundant fibrillary collagenous stroma; low power fields lacking adipocytes
IHC: MDM2
FISH: MDM2 amplified
Liposarcoma, "low-grade" dedifferentiation
Hypocellular; spindle-stellate cells arranged in loose fascicles
Dense eosinophilic cytoplasm
Ovoid and hyperchromatic nuclei with moderate pleomorphism; inconspicuous mitotic activity
Scattered epithelioid cells, some with multinucleation
Abundant fibrillary collagenous stroma; low power fields lacking adipocytes
IHC: MDM2
FISH: MDM2 amplified
Liposarcoma, "low-grade" dedifferentiation
Hypocellular; spindle-stellate cells arranged in loose fascicles
Dense eosinophilic cytoplasm
Ovoid and hyperchromatic nuclei with moderate pleomorphism; inconspicuous mitotic activity
Abundant fibrillary collagenous stroma; low power fields lacking adipocytes
FISH: MDM2 amplified
Dedifferentiated liposarcoma
Moderately cellular; spindle-polygonal cells with patternless distribution
Dense eosinophilic cytoplasm with occasional clear vacuoles
Ovoid and hyperchromatic nuclei with moderate pleomorphism and frequent multinucleation; rare mitotic activity
Prominent collagenous-myxoid stroma
IHC: MDM2
FISH: MDM2 amplified
Dedifferentiated liposarcoma, undifferentiated pleomorphic sarcoma (UPS)-like
Cellular; spindle-polygonal cells with vague storiform pattern
Dense eosinophilic cytoplasm with occasional clear vacuoles
Ovoid and hyperchromatic nuclei with moderate pleomorphism and occasional multinucleation; conspicuous mitotic activity
IHC: MDM2, CDK4
FISH: MDM2 amplified
Dedifferentiated liposarcoma, undifferentiated pleomorphic sarcoma (UPS)-like
Cellular; spindle-polygonal cells with vague storiform pattern
Dense eosinophilic cytoplasm with occasional clear vacuoles
Ovoid and hyperchromatic nuclei with moderate pleomorphism and occasional multinucleation; mitotic activity
Prominent lymphoplasmacytic inflammatory infiltrate
IHC: MDM2, CDK4
FISH: MDM2 amplified
Dedifferentiated liposarcoma, undifferentiated pleomorphic sarcoma (UPS)-like
Cellular; spindle-polygonal cells with vague storiform pattern
Dense eosinophilic cytoplasm with occasional clear vacuoles
Ovoid and hyperchromatic nuclei with moderate pleomorphism and occasional multinucleation; mitotic activity
IHC: MDM2
FISH: MDM2 amplified
Dedifferentiated liposarcoma, myxofibrosarcoma-like
Hypocellular; spindle-polygonal cells with patternless distribution
Dense eosinophilic cytoplasm with occasional clear vacuoles
Ovoid and hyperchromatic nuclei with moderate pleomorphism and frequent multinucleation; mitotic activity
Prominent myxoid stroma with arcing thin-walled vasculature
FISH: MDM2 amplified
PMID: 15832195
Dedifferentiated liposarcoma, with meningothelial-like whorls and metaplastic bone formation
Variable cellularity; spindle-stellate cells arranged in loose fascicles punctuated by whorls-storiform patterns
Eosinophilic cytoplasm with long tapering processes
Ovoid nuclei with vesicular chromatin, small nucleoli and mild pleomorphism; inconspicuous mitotic activity
Scattered epithelioid cells, some with multinucleation and moderate pleomorphism
Abundant collagenous stroma; metaplastic bone; background of well-differentiated liposarcoma
FISH: MDM2 amplified
PMID: 21317707
Dedifferentiated liposarcoma, with meningothelial-like whorls and metaplastic bone formation
Variable cellularity; spindle-stellate cells arranged in loose fascicles punctuated by whorls-storiform patterns
Eosinophilic cytoplasm with long tapering processes
Ovoid nuclei with mild pleomorphism; inconspicuous mitotic activity
Scattered epithelioid cells, some with multinucleation and marked pleomorphism
Abundant collagenous stroma; calcified nodules
Mild chronic inflammatory infiltrate
FISH: MDM2 amplified
PMID: 21317707
Dedifferentiated liposarcoma, with heterologous rhabdomyoblastic differentiation
Cellular; spindle cell fascicles with clusters of polygonal cells
Spindle cells have scant eosinophilic cytoplasm and occasional clear vacuoles; ovoid and hyperchromatic nuclei with moderate pleomorphism; mitotic activity
Polygonal cells have abundant eosinophilic cytoplasm; eccentric nuclei
IHC: desmin, myogenin, MDM2
FISH: MDM2 amplified
Dedifferentiated liposarcoma, with heterologous leiomyosarcomatous differentiation
Cellular spindle cell fascicles arising in well-differentiated background
Eosinophilic cytoplasm with fibrillary processes and occasional clear vacuoles
Ovoid and elongated nuclei with mild pleomorphism; mitotic activity
IHC: H-caldesmon, MDM2
FISH: MDM2 amplified
PMID: 7943536
Dedifferentiated liposarcoma, with heterologous osteosarcomatous differentiation
Spindle-polygonal cells arranged in sheets
Eosinophilic-amphophilic cytoplasm with occasional vacuoles
Ovoid and hyperchromatic nuclei with moderate pleomorphism and occasional multinucleation; mitotic activity
Areas of chondroid and osteoid matrix
Mild chronic inflammatory infiltrate
FISH: MDM2 amplified
PMID: 7943536
Dedifferentiated liposarcoma, with epithelioid features
Sheets of epithelioid-spindle cells
Abundant amphophilic cytoplasm
Central-eccentric round-ovoid nuclei with macronucleoli and moderate pleomorphism; brisk mitotic activity
IHC: MDM2, CDK4
FISH: MDM2 amplified
Dedifferentiated liposarcoma, with epithelioid features
Sheets of epithelioid-spindle cells
Abundant amphophilic cytoplasm
Central-eccentric round-ovoid nuclei with macronucleoli and moderate pleomorphism; brisk mitotic activity
Mild acute and chronic inflammatory infiltrate
IHC: MDM2, CDK4
FISH: MDM2 amplified
PMID: 28719466
Dedifferentiated liposarcoma, with "homologous" lipoblastic (pleomorphic liposarcoma-like) differentiation
Sheets of adipocytes admixed with spindle-epithelioid cells
Clear-eosinophilic cytoplasm
Round-ovoid, hyperchromatic, and pleomorphic nuclei; inconspicuous mitotic activity
Interspersed pleomorphic lipoblasts; necrosis
FISH: MDM2 amplified
PMID: 20588177