Pathology: alveolar soft part sarcoma

Alveolar soft part sarcoma

  • Nests of polygonal cells, surrounded by delicate fibrovascular septa

  • Abundant granular eosinophilic cytoplasm

  • Monomorphic round-ovoid nuclei with prominent nucleoli; inconspicuous mitotic activity

  • IHC: TFE3

  • FISH: TFE3-rearrangement

Alveolar soft part sarcoma

  • Nests of polygonal cells, surrounded by delicate fibrovascular septa

  • Abundant granular eosinophilic cytoplasm

  • Monomorphic round-ovoid nuclei with prominent nucleoli; inconspicuous mitotic activity

  • IHC: TFE3

  • FISH: ASPSCR1 and TFE3 rearrangement

Alveolar soft part sarcoma

  • Epithelioid cells with nested-pseudoalveolar pattern surrounded by delicate fibrovascular septa

  • Abundant granular eosinophilic cytoplasm

  • Monomorphic round nuclei with prominent nucleoli; inconspicuous mitotic activity

  • IHC: TFE3

  • RNA-seq: ASPSCR1::TFE3 gene fusion

Alveolar soft part sarcoma

  • Epithelioid cells with nested-pseudoalveolar pattern surrounded by delicate fibrovascular septa

  • Abundant amphophilic cytoplasm

  • Round-ovoid nuclei with moderate pleomorphism, occasional binucleation and prominent nucleoli; inconspicuous mitotic activity

  • IHC: TFE3

  • FISH: TFE3-rearrangement