Orbital Tumours

Primary and secondary tumours of the orbit. They present with proptosis, displacement of the globe, pain, diplopia and visual loss, and are classified by age, location and histology.

• Children: capillary (infantile) haemangioma, lymphangioma (lymphatic malformation), dermoid cyst, rhabdomyosarcoma, optic nerve glioma, plexiform neurofibroma, neuroblastoma metastasis, leukaemic infiltrate (chloroma), Langerhans cell histiocytosis, teratoma.
• Adults: cavernous haemangioma (most common benign adult tumour), lymphoproliferative disease (lymphoma, 10 to 15 percent of orbital masses), idiopathic orbital inflammation, optic nerve sheath meningioma, solitary fibrous tumour, schwannoma, neurofibroma, lacrimal gland tumours (pleomorphic adenoma, adenoid cystic carcinoma), metastases (breast, lung, prostate), secondary extension (sinus carcinoma, basal and squamous cell carcinoma of lids, conjunctival and uveal melanoma, retinoblastoma, intracranial meningioma).
• Location: intraconal (cavernous haemangioma, schwannoma, optic nerve lesions), extraconal (lymphoma, lacrimal gland, dermoid, metastasis), muscle (metastasis, myositis, lymphoma), bone (fibrous dysplasia, osteoma, meningioma).

• Slowly progressive painless axial proptosis (cavernous haemangioma, schwannoma, meningioma); rapid proptosis with pain or inflammation (rhabdomyosarcoma, metastasis, adenoid cystic carcinoma, lymphoma in aggressive types).
• Globe displacement away from the mass (inferomedial for lacrimal gland tumour, downward for frontal lesion), palpable mass (anterior tumours), ptosis or S-shaped lid, diplopia, optic nerve compromise (reduced vision, relative afferent pupillary defect, disc swelling, choroidal folds), hypoglobus, infraorbital numbness (perineural infiltration), and pulsation.
• Intermittent proptosis on Valsalva: varix; blue discolouration or salmon patch: lymphoma or capillary haemangioma; fluctuating swelling and sudden haemorrhage ("chocolate cyst"): lymphangioma.

• Orbital CT (bone remodelling, calcification, phleboliths, destruction) and MRI with fat suppression and gadolinium (soft tissue, optic nerve, intracranial extent); orbital ultrasound for anterior cystic lesions; PET-CT for lymphoma and metastasis; chest imaging and abdominal imaging for staging.
• Haematology and serum markers: full count, LDH, protein electrophoresis, thyroid function, IgG4, urine catecholamines in children, tumour markers when metastasis suspected.
• Tissue diagnosis: fine needle aspiration or incisional biopsy with fresh tissue for immunohistochemistry and flow cytometry (lymphoma); excisional biopsy for encapsulated lesions (cavernous haemangioma, schwannoma, dermoid); avoid biopsy of suspected pleomorphic adenoma and optic nerve sheath meningioma.

• Cavernous haemangioma: observation if asymptomatic; surgical excision (lateral orbitotomy or transcranial) for compressive optic neuropathy, diplopia, or significant proptosis.
• Dermoid cyst: complete excision with the capsule intact (rupture causes severe inflammation); orbital rim and lacrimal fossa lesions.
• Capillary haemangioma: oral propranolol 2 to 3 mg/kg/day in two or three divided doses for 6 to 12 months (with glucose and heart rate monitoring), topical timolol 0.5 percent twice daily for small lesions.
• Lymphatic malformation: sirolimus (0.8 mg/m2 twice daily, target trough 10 to 15 ng/mL), sclerotherapy (bleomycin, OK-432, doxycycline), surgical debulking for haemorrhage.
• Orbital lymphoma: low grade (marginal zone) radiotherapy 24 to 30 Gy in 12 to 15 fractions or rituximab 375 mg/m2 weekly for 4; doxycycline 100 mg twice daily for 3 weeks for Chlamydia associated disease; high grade: R-CHOP chemotherapy.
• Pleomorphic adenoma: complete en bloc excision with the capsule, avoiding biopsy.
• Malignant tumours: multimodal therapy (surgery, radiotherapy, chemotherapy) at a specialist centre; exenteration for locally invasive disease with no globe sparing option.
• Fibrous dysplasia: observation and treat only complications.
• Follow up with imaging for recurrence and visual function.