Pathology: fibroma of tendon sheath

Fibroma of tendon sheath

  • Hypocellular; spindle-stellate cells with storiform-fascicular pattern

  • Eosinophilic cytoplasm

  • Hyperchromatic ovoid nuclei with occasional multinucleation; rare mitotic activity

  • Dense collagenous stroma; delicate thin-walled vessels

  • RNA-seq: MYH9::USP6 gene fusion

  • PMID: 27125357, 34088995

Fibroma of tendon sheath

  • Circumscribed; spindle-stellate cells with storiform-fascicular pattern

  • Eosinophilic cytoplasm

  • Monomorphic ovoid nuclei with small nucleoli; rare mitotic activity

  • Dense collagenous stroma; delicate thin-walled vessels

Fibroma of tendon sheath

  • Circumscribed; spindle-stellate cells with storiform-fascicular pattern

  • Eosinophilic cytoplasm

  • Monomorphic ovoid nuclei with hyperchromasia and small nucleoli; inconspicuous mitotic activity

  • Dense collagenous stroma; delicate thin-walled vessels

  • IHC: smooth muscle actin


Fibroma of tendon sheath

  • Circumscribed; spindle-stellate cells with storiform-fascicular pattern

  • Eosinophilic cytoplasm

  • Monomorphic ovoid nuclei with hyperchromasia and small nucleoli; inconspicuous mitotic activity

  • Dense collagenous stroma; delicate thin-walled vessels

  • IHC: smooth muscle actin