Pathology: sclerosing epithelioid fibrosarcoma

Sclerosing epithelioid fibrosarcoma

  • Cellular; sheets of epithelioid cells

  • Eosinophilic cytoplasm

  • Monomorphic ovoid nuclei; occasional mitotic activity

  • Bands of sclerotic collagen; ectatic thin-walled vasculature

  • IHC: MUC4

  • RNA-seq: EWSR1::CREB3L1 gene fusion

Sclerosing epithelioid fibrosarcoma

  • Cellular; sheets of epithelioid cells

  • Eosinophilic cytoplasm

  • Monomorphic ovoid nuclei; inconspicuous mitotic activity

  • Thick collagen bands; ectatic thin-walled vasculature

  • IHC: MUC4

  • RNA-seq: FUS::CREB3L2 gene fusion

Sclerosing epithelioid fibrosarcoma

  • Cellular; nests and cords of epithelioid cells

  • Eosinophilic cytoplasm

  • Monomorphic ovoid nuclei; mitotic activity

  • Thin bands of sclerotic collagen; inconspicuous vasculature

  • IHC: MUC4

  • RNA-seq: EWSR1::CREB3L1 gene fusion