Pathology: epithelioid sarcoma

Epithelioid sarcoma, distal-type

  • Infiltrative; fascicles of spindle cells

  • Pale amphophilic cytoplasm

  • Ovoid nuclei with prominent nucleoli and moderate pleomorphism; mitotic activity

  • Focal necrosis

  • IHC: CD34, keratin (AE1/AE3), INI-1

Epithelioid sarcoma, distal-type

  • Lobulated; fascicles of spindle-polygonal cells

  • Eosinophilic cytoplasm

  • Ovoid nuclei with vesicular chromatin, prominent nucleoli and moderate pleomorphism; inconspicuous mitotic activity

  • Delicate collagenous stroma

  • IHC: keratin (AE1/AE3), INI-1

Epithelioid sarcoma, proximal-type

  • Lobulated; sheets and nests of epithelioid cells

  • Pale amphophilic cytoplasm

  • Round-ovoid nuclei with macronucleoli, vesicular chromatin and mild pleomorphism; conspicuous mitotic activity

  • Focal necrosis

  • IHC: keratin (AE1/AE3), INI-1

Epithelioid sarcoma, proximal-type

  • Sheets and nests of epithelioid cells

  • Amphophilic cytoplasm

  • Round-ovoid nuclei with occasional clefts, prominent nucleoli, and mild pleomorphism; mitotic activity

  • IHC: keratin (AE1/AE3), INI-1

Epithelioid sarcoma, proximal-type

  • Sheets and nests of epithelioid cells

  • Pale amphophilic cytoplasm

  • Round-ovoid nuclei with macronucleoli, vesicular chromatin and mild pleomorphism; mitotic activity

  • Focal necrosis

  • IHC: INI-1

Epithelioid sarcoma, proximal-type

  • Sheets and nests of epithelioid cells

  • Pale amphophilic cytoplasm

  • Round-ovoid nuclei with macronucleoli, vesicular chromatin and mild pleomorphism; conspicuous mitotic activity

  • Focal necrosis

  • IHC: INI-1