Nests of round cells
Scant eosinophilic cytoplasm with indistinct cell borders
Monomorphic round nuclei; mitotic activity
Intervening fibrous stroma; necrosis
IHC: WT-C
RNA-seq: EWSR1::WT1 gene fusion
Nests of round cells
Scant eosinophilic cytoplasm with indistinct cell borders
Monomorphic round nuclei; mitotic activity
Intervening fibrous stroma; necrosis
IHC: desmin, keratin (AE1/AE3)
RNA-seq: EWSR1::WT1 gene fusion
Nests of polygonal cells
Eosinophilic cytoplasm with indistinct cell borders
Round nuclei with moderate atypia; mitotic activity
Intervening fibrous stroma; necrosis
RNA-seq: EWSR1::WT1 gene fusion
Sheets of round-epithelioid cells
Pale eosinophilic cytoplasm
Round-ovoid nuclei; mitotic activity
Focal myxoid stroma
IHC: desmin
RNA-seq: EWSR1::WT1 gene fusion
Sheets of round-epithelioid cells
Pale eosinophilic cytoplasm
Round-ovoid nuclei; mitotic activity
Focal myxoid stroma
IHC: desmin
RNA-seq: EWSR1::WT1 gene fusion
Sheets and nests of round cells
Scant eosinophilic cytoplasm with indistinct cell borders
Monomorphic round nuclei; mitotic activity
Intervening fibrous stroma
IHC: desmin, keratin (AE1/AE3)
FISH: EWSR1-rearrangement