Tumours, masses and neoplasia


  • Most common primary orbital malignancy in childhood

    • Third most common solid extracranial tumour of childhood (after Wilm’s tumour and neuroblastoma)
  • Relatively good prognosis

  • M>F

  • Can affect the orbit, eyelids, conjunctiva and rarely the uveal tract

  • Originates from primitive pluripotent mesenchymal cells

  • Generally well circumscribed with occasional areas of haemorrhage

  • Usually intraconal or within superior orbit

Histological types

  • Embryonal (84%): good prognosis

    • Cellular and myxoid areas, central nucleus and highly eosinophilic cytoplasm
  • Alveolar (9%): worst prognosis

    • Loosely adherent eosinophilic rhabdomyoblasts
  • Pleomorphic (very rare, typically occurs in adults)

    • Best prognosis
  • Botyroid (4%)

Immunohistochemical stains

  • Desmin
  • Muscle-specific actin
  • Myoglobin

Clinical features

  • Presents as non-axial proptosis which can be rapid onset, chemosis, eyelid discolouration, ophthalmoplegia. Only 10% experience pain


  • CT/MRI: well-defined mass with bony destruction


  • Biopsy
  • Systemic workup
  • Surgical excision: only if small and encapsulated lesion
  • Combined radio/chemotherapy: mainstay

Was this page helpful?