Orbital tumour and proptosis

Proptosis is forward displacement of the globe within the orbit. Other masses move the eye sideways or vertically, sometimes with little apparent forward prominence. A patient's report that one eye looks different may therefore reveal an orbital disorder even when they do not use the word bulging. Compare both eyes, establish whether the appearance is new and distinguish displacement from lid retraction, globe enlargement or longstanding facial asymmetry. Old photographs can clarify the history but should not delay assessment of a concerning change.

The orbit contains muscles, fat, nerves, vessels, the lacrimal gland and connective tissue in a confined bony space. Lesions may originate in any of these structures, spread from adjacent sinuses or skull, or represent metastatic or haematological disease. Benign lesions can cause serious disability through compression; malignancy cannot be inferred from pain or prominence alone. Clinical assessment should answer two parallel questions: whether visual function is at risk now, and what process is producing the displacement.

Tempo is particularly useful. Sudden painful proptosis suggests haemorrhage, infection or another acute orbital event. Enlargement over days or weeks raises concern about aggressive tumour or inflammation, while a slow painless course can occur with a benign mass, lymphoma or other neoplasm. These patterns guide the differential without providing a tissue diagnosis. A tumour may also bleed, so an abrupt presentation does not remove neoplasia from consideration. Ask about trauma, procedures, sinus symptoms, thyroid disease and anticoagulants as well as previous cancer.

Localisation helps organise further investigation. A lesion within the muscle cone may displace the globe forwards, whereas a mass outside it often moves the globe away from its site. Superolateral fullness can point towards the lacrimal region. Deep apical disease may affect the optic nerve before there is striking external swelling. Assess acuity, colour discrimination, pupils, fields, eye movements, corneal exposure and the visible optic disc, documenting what can and cannot be reliably tested. No single normal finding establishes that the orbit is safe.

Common diagnostic categories include thyroid eye disease, inflammatory disease, vascular malformations, benign encapsulated lesions, lymphoma, lacrimal tumours and secondary malignancy. In children, congenital cysts and vascular lesions coexist in the differential with aggressive processes such as rhabdomyosarcoma, neuroblastoma-related disease and haematological infiltration. Newly apparent proptosis in a child warrants immediate hospital assessment rather than a period of observation based solely on the child's general wellbeing.

Specialist orbital imaging maps the lesion, its relation to the optic nerve and muscles, and any extension beyond the orbit. MRI is useful for soft tissue and the orbital apex; CT may be preferable when bone, sinuses, calcification or an acute process needs assessment. The clinical question determines the protocol, contrast and any vascular study. Imaging sometimes provides a sufficiently characteristic diagnosis for observation, but many lesions require tissue sampling. This decision belongs with the orbital team because the safest access and the consequences of biopsy vary substantially.

Treatment follows the diagnosis, visual risk and patient's priorities. An established benign lesion may be monitored or removed if growing or symptomatic. A suspected lymphoma needs an appropriately handled specimen and subsequent haematological assessment; treatment can involve radiotherapy or systemic therapy according to subtype and extent. Other tumours require their own surgical or oncological plan. Avoid promising that every orbital mass can be cured by simple excision. An early discussion of uncertainty, anticipated tests and the clinician responsible for results helps patients navigate a potentially distressing referral.