Fascicles of spindle-ovoid cells and nests of round cells
Pale amphophilic cytoplasm
Round-ovoid nuclei with vesicular chromatin, small nucleoli and mild pleomorphism; inconspicuous mitotic activity
Myxocollagenous stroma; delicate branching vasculature
IHC: SATB2, CD99
RNA-seq: BCOR::CCNB3 gene fusion
Heterogeneous morphology including spindle cells in loose fascicles, and sheets of ovoid-round cells
Pale eosinophilic cytoplasm
Round-ovoid nuclei with small nucleoli and mild atypia; inconspicuous mitotic activity
Collagenous-myxoid stroma; delicate vasculature
IHC: SATB2
RNA-seq: BCOR::CCNB3 gene fusion
Sheets-nests of epithelioid-ovoid cells
Pale eosinophilic cytoplasm
Round-ovoid nuclei with vesicular chromatin, small nucleoli and mild-moderate pleomorphism; mitotic activity
Prominent sinusoidal vasculature with occasional large thick-walled vessels
RNA-seq: BCOR::CCNB3 gene fusion