Giant cell tumour of frontal bone in a patient with bilateral retinoblastoma.

A case is presented of a 5 year-old patient with bilateral hereditary retinoblastoma treated with radiotherapy in the right eye and enucleation of the left eye. After three years without evidence of progression, the patient presented with a right orbital mass that compromised the frontal bone. After surgical excision, the histology analysis was consistent with a diagnosis of giant cell tumour. Primary orbital bone neoplasms, such as giant cell tumours, are extremely rare. Both radiological and histopathology studies are essential to establish the differential diagnosis of orbital mass lesions.