Spindle-polygonal cells with patternless distribution
Pale aeosinophilic cytoplasm
Round-ovoid nuclei with prominent nucleoli and moderate pleomorphism; mitotic activity
Collagenous stroma; inflammatory infiltrate; necrosis
IHC: MDM2, CDK4
FISH: polysomy
Spindle-polygonal cells with patternless distribution
Pale aeosinophilic cytoplasm
Round-ovoid nuclei with prominent nucleoli and moderate pleomorphism; mitotic activity
Necrosis
IHC: MDM2, CDK4
FISH: MDM2 amplified
Polygonal cells with patternless distribution
Pale amphophilic cytoplasm
Round-ovoid nuclei with prominent nucleoli and marked pleomorphism; mitotic activity
Collagenous stroma; prominent ectatic vessels lined by atypical cuboidal endothelial cells; mild chronic inflammation, and eosinophils; necrosis
IHC: MDM2, CDK4
FISH: MDM2 amplified
Sheets and fascicles of spindle-epithelioid cells
Pale amphophilic cytoplasm
Round-ovoid nuclei with irregular membranes, small nucleoli, moderate pleomorphism and occasional multinucleation; mitotic activity
Myxoid-collagenous stroma; necrosis
IHC: MDM2
FISH: MDM2 amplified
Spindle-stellate cells with storiform pattern
Pale amphophilic cytoplasm with delicate processes
Ovoid nuclei with small nucleoli and mild pleomorphism; inconspicuous mitotic activity
Focal collagenous stroma; mild chronic inflammation
FISH: MDM2 amplified
Spindle-stellate cells with loose fascicular-storiform pattern
Pale eosinophilic cytoplasm with delicate processes
Ovoid nuclei with small nucleoli and mild pleomorphism; inconspicuous mitotic activity
Loose myxoid-collagenous stroma; mild chronic inflammation; necrosis
IHC: MDM2
FISH: MDM2 amplified