Approach to Diagnosis of Orbital Tumours

Although the most common orbital disease is thyroid orbitopathy, neoplasia accounts for one fifth of orbital patients. Most orbital tumours tend to present in a sub-acute to chronic fashion, but some malignant neoplastic disorders may present acutely and must be ruled out quickly. Displacement of the globe is the main orbital tumour symptom, and a complete ocular examination should be done including exophthalmometry. Ancillary tests are useful in orbital disease diagnosis. Computed tomography is the main orbital imaging technique, and allows the clinician to distinguish between solid and cystic lesions, evaluate size and location, and suspect malignancy. Bone destruction indicates aggressive neoplasia, while moulding indicates slow-growing benign tumours. Magnetic resonance imaging is useful in studying the orbital apex and soft tissues. Clinical and imaging suspicions are usually confirmed by orbital biopsy. The main orbital tumour categories include lymphoma, vascular tumours, epithelial lacrimal gland tumours, neural tumours and metastases. Cavernous haemangioma is the most common benign orbital tumour in adults and can be seen as a well-circumscribed ovoid orbital mass occupying the intraconal space. A downward and nasal displacement of the eye is seen in lacrimal gland tumours. Pleomorphic adenoma is the most common, and it should be excised intact without previous biopsy due to the risk of malignant transformation. Most orbital metastases present as painful and rapidly growing unilateral and solitary masses.