Epithelioid-spindle-stellate cells
Eosinophilic cytoplasm
Ovoid nuclei with small nucleoli; inconspicuous mitotic activity
Abundant myxoid stroma
RNA-seq: EWSR1::NR4A3 gene fusion
Lobulated; cords of epithelioid-spindle cells
Eosinophilic cytoplasm
Ovoid nuclei with small nucleoli; inconspicuous mitotic activity
Abundant myxoid stroma
RNA-seq: EWSR1::NR4A3 gene fusion
Lobulated; cords of epithelioid-spindle cells
Eosinophilic cytoplasm
Ovoid nuclei with small nucleoli; mitotic activity
Abundant myxoid stroma
RNA-seq: EWSR1::NR4A3 gene fusion
Lobulated; nests and cords of epithelioid-spindle cells
Eosinophilic cytoplasm
Ovoid nuclei with small nucleoli; mitotic activity
Abundant myxoid stroma
RNA-seq: EWSR1::NR4A3 gene fusion
Anastomosing cords of epithelioid-spindle cells
Pale amphophilic cytoplasm with delicate processes
Ovoid nuclei with small nucleoli and mild pleomorphism; inconspicuous mitotic activity
Abundant myxoid stroma; small blood vessels with occasional perivascular hyalinization
RNA-seq: EWSR1::NR4A3 gene fusion
Lobulated; sheets and cords of epithelioid-spindle cells
Eosinophilic cytoplasm
Ovoid nuclei with inconspicuous nucleoli; inconspicuous mitotic activity
Abundant myxoid stroma
RNA-seq: EWSR1::NR4A3 gene fusion
Anastomosing cords of epithelioid-spindle cells
Pale eosinophilic cytoplasm with delicate processes
Ovoid nuclei with small nucleoli and mild pleomorphism; inconspicuous mitotic activity
Abundant myxoid stroma
RNA-seq: EWSR1::NR4A3 gene fusion
Nests, chains and isolated round-rhabdoid cells
Eosinophilic cytoplasm
Eccentric reniform hyperchromatic nuclei with mild pleomorphism; mitotic activity
Abundant myxoid stroma
RNA-seq: EWSR1::NR4A3 gene fusion
Sheets, nests, and cords of round-rhabdoid cells
Eosinophilic cytoplasm
Round-reniform nuclei with small nucleoli and mild pleomorphism; mitotic activity
Abundant myxoid stroma
IHC: S100
RNA-seq: FUS::NR4A3 gene fusion
Sheets of round-epithelioid cells, with peritheliomatous pattern; loose fascicles of spindle cells
Eosinophilic cytoplasm
Round-ovoid nuclei with macronucleoli and mild pleomorphism; mitotic activity
Abundant necrosis
RNA-seq: TAF15::NR4A3 gene fusion
Anastomosing cords of epithelioid-stellate cells
Pale amphophilic cytoplasm with delicate processes
Small ovoid hyperchromatic nuclei with mild pleomorphism; inconspicuous mitotic activity
Abundant myxoid stroma
RNA-seq: EWSR1::NR4A3 gene fusion
Sheets of round-epithelioid cells
Dense eosinophilic and granular cytoplasm
Round-ovoid nuclei with macronucleoli and mild pleomorphism; mitotic activity
RNA-seq: EWSR1::NR4A3 gene fusion
Sheets of round-epithelioid cells
PAmphophilic cytoplasm with indistinct cell borders
Round-ovoid nuclei with prominent nucleoli and mild pleomorphism; rare mitotic activity
Delicate thin-walled vasculature
RNA-seq: EWSR1::NR4A3 gene fusion
Nests and broad anastomosing cords of epithelioid-stellate cells
Pale amphophilic cytoplasm
Round-ovoid nuclei with prominent nucleoli and mild pleomorphism; inconspicuous mitotic activity
Abundant myxoid stroma
RNA-seq: EWSR1::NR4A3 gene fusion
Anastomosing cords of epithelioid-spindle cells
Pale amphophilic cytoplasm with delicate processes
Small ovoid hyperchromatic nuclei with mild pleomorphism; inconspicuous mitotic activity
Abundant myxoid stroma
RNA-seq: EWSR1::NR4A3 gene fusion