Pathology: EWSR1::SMAD3-positive fibroblastic tumour

Lobulated; spindle cell fascicles 

Scant amphophilic cytoplasm with long tapering processes

Monomorphic ovoid and elongated nuclei; inconspicuous mitotic activity 

Collagenous stroma with central hyalinization

IHC: ERG

RNA-seq: EWSR1::SMAD3 gene fusion

Lobulated; spindle cell fascicles 

Scant amphophilic cytoplasm with long tapering processes

Monomorphic ovoid and elongated nuclei; inconspicuous mitotic activity 

Central hyalinization with necrosis and stippled calcification; peripherally there is focal myxoid stroma

IHC: ERG

RNA-seq: EWSR1::SMAD3 gene fusion

PMID: 29309308, 29957732