Pathology: glomus tumour

Glomus tumour

  • Circumscribed; sheets of round-polygonal cells

  • Bright eosinophilic cytoplasm

  • Monomorphic round nuclei with small nucleoli; inconspicuous mitotic activity

  • Medium-sized vessels with hyalinized walls

  • IHC: H-caldesmon

Glomus tumour

  • Circumscribed; sheets and anastamosing cords of round-polygonal cells

  • Pale amphophilic cytoplasm

  • Monomorphic round nuclei with small nucleoli; inconspicuous mitotic activity

  • Prominent fibromyxoid stroma

  • IHC: H-caldesmon

Glomangioma

  • Circumscribed; sheets-cords of round-polygonal cells

  • Bright eosinophilic cytoplasm

  • Monomorphic round nuclei with small nucleoli; inconspicuous mitotic activity

  • Prominent medium-large vessels of variable thickness

  • IHC: H-caldesmon

Glomangioma

  • Circumscribed; sheets-cords of round-polygonal cells

  • Pale eosinophilic cytoplasm

  • Monomorphic round nuclei with small nucleoli; inconspicuous mitotic activity

  • Prominent ectatic vessels of variable size and thickness

  • IHC: H-caldesmon

Glomus tumour, symplastic

  • Lobulated; sheets of round-polygonal cells

  • Pale amphophilic cytoplasm

  • Round nuclei with small nucleoli and mild pleomorphism; inconspicuous mitotic activity

  • IHC: CD34, smooth muscle actin, H-caldesmon

Glomus tumour, malignant

  • Infiltrative; sheets of round-polygonal cells

  • Pale amphophilic cytoplasm

  • Round nuclei with small nucleoli and mild pleomorphism; conspicuous mitotic activity

  • Necrosis

  • IHC: H-caldesmon

  • RNA-seq: MIR143::NOTCH1 gene fusion