Optic nerve breast metastasis mimicking meningioma

Purpose: We report on an optic nerve breast metastasis masquerading initial ly as a central retinal vein occlusion and later as an optic nerve meningio ma. Methods: A 60-year-old female presented with a left central retinal vein oc clusion (CRVO). She represented 7 months later with left upper ptosis, prop tosis and painful rubeotic glaucoma. Computed tomography (CT) and magnetic resonance imaging suggested an optic nerve meningioma. On referral to the r egional orbital unit, a mild left external ophthalmoplegia was noted and, i n view of previous right mastectomy and chemotherapy 3 years earlier, the l eft optic nerve war biopsied simultaneously with left enucleation of her pa inful eye. Results: Histopathology showed infiltration of the optic nerve and meningea l sheath spreading into the subretinal space and vitreous by malignant epit helial cells, consistent with breast origin. Further CT imaging and bone sc ans revealed no other metastases. Single field left orbit radiotherapy of 2 0 Gy was given in five fractions and Arimidex (Zeneca Pharmaceuticals, Ches hire, England) was commenced with the cessation of tamoxifen. The patient w as also given an ocular prosthesis. Sadly, st-ie lost vision in her other e ye due to retrograde malignant invasion of her optic chiasm and died 6 week s later. Conclusions: Orbital and choroidal metastases are relatively common but iso lated optic nerve metastases are extremely rare. Progressive infiltration o f the nerve is likely to enhance CRVO ischaemia and resultant rubeotic glau coma. in the diagnosis of CRVO, proptosis or external ophthalmoplegia, the presence of pre-existing malignant disease should raise concerns, as delay in diagnosis may affect outcome, particularly if the metastases are sensiti ve to pharmacological therapy.