Pathology: CIC-rearranged sarcoma

Sheets-nests of epithelioid-round cells

Pale eosinophilic cytoplasm with occasional vacuoles

Round nuclei with small nucleoli and mild pleomorphism; mitotic activity

Collagenous-hyalinized stroma

IHC: EMA, S100, WT-1

RNA-seq: CIC::DUX4 gene fusion

Sheets of round-epithelioid cells

Pale amphophilic cytoplasm

Round-ovoid nuclei with coarse chromatin, small nucleoli and mild-moderate pleomorphism; mitotic activity

Necrosis

IHC: WT1, CD99

RNA-seq: CIC::DUX4L2 gene fusion

Sheets-nests of round cells

Pale eosinophilic cytoplasm

Round nuclei with small nucleoli and mild pleomorphism; mitotic activity

Delicate thin-walled vasculature

IHC: CD99

FISH: CIC-rearrangement

Sheets-nests of round cells

Pale eosinophilic cytoplasm

Round nuclei with small nucleoli and mild pleomorphism; mitotic activity

Delicate thin-walled vasculature

IHC: CD99, WT1

FISH: CIC-rearrangement