Periorbital and orbital swellings

Swellings related to the supraorbital margin

Dermoid cysts

Dermoid cysts are usually external angular cysts although they may occur medially (Fig. 36.1). They often cause a bony depression by their pressure, and may have a dumb-bell extension into the orbit. They can also erode the orbital plate of the frontal bone, to become attached to dura, and for this reason it is important to do computerised tomography (CT) of the area before excision.

Neurofibromatosis

Neurofibromatosis may also produce swellings above the eye. The diagnosis can usually be confirmed by an examination of the whole body, as there are often multiple lesions. Proptosis can also result (Fig. 36.2).

Swellings of the lids

Meibomian cysts (chalazion)

These are the most common lid swellings (Fig. 36.3). A meibomian cyst is a chronic granulomatous inflammation of a meibomian gland. It may occur on either upper or lower lids and presents as a smooth painless swelling. It can be felt by rolling the cyst on the tarsal plate. It is distinguished from a stye (hordeolum) which is an infection of a hair follicle, usually painful. Meibomian cysts are treated by incision and curettage from the conjunctival surface. Styes are treated by antibiotics and local heat.

Basal cell carcinomas (rodent ulcers)

This is the most common malignant tumour of the eyelids (Fig. 36.4). It is locally malignant, is more common on the lower lids, and usually starts as a small pimple which ulcerates and has raised edges. It is easily excised in the early stages, and can be treated with local radiotherapy if too big to be excised.

Other lid swellings

These can occur, but are less common. These include seba­ceous cysts, papillomas, keratoacanthosis, cysts of Moll (Fig. 36.5) (sweat glands) or Zeiss (sebaceous glands) and molluscum contagiosum. When molluscum contagiosum occurs on the lid margin, they can give rise to a mild kerato­conjunctivitis and should be curetted.

Carcinoma of the meibomian glands and rhabdomyosarcomas are rare lesions; they need to be treated radically. Meibomian cysts that recur frequently should be submitted to biopsy.

Swellings of the Lacrimal system

Lacrimal sac mucocele

This occurs from obstruction of the lacrimal duct beyond the sac, and results in a fluctuant swelling, which bulges out just below the medial canthus. It can become infected to give rise to a painful tense swelling (acute dacryocystitis). If untreated it may give rise to a fistula. Treatment is by performing a bypass operation between the lacrimal sac and the nose [a dacryocystorrhinostomy (DCR)]. 

 Watering of the eye can occur due to eversion of the lower lid (ectropion), which causes loss of contact between the lower punctum and the tear film, and this must be distinguished from a mucocele.

Lacrimal gland tumours

Pathologically these resemble parotid turnouts (Chapter 42). These are swellings of the gland which lie in the upper lateral aspect of the orbit, and eventually they lead to impairment of ocular movements and displacement of the globe forwards, downwards and inwards. They can be pleomorphic adeno­mas with or without carcinomatous change, carcinomas or mucoepidermoid tumours.

Orbital swellings

If these reach any size they result in displacement of the globe and limitation of movement. A full description of these is outside the realm of the text, but some of the most common causes include the following.

  Pseudoproptosis. This results from a large eyeball, as seen in congenital glaucoma or high myopia.

Orbital inflammatory conditions result in orbital cellulitis (Fig. 36.6).

   Haemorrhagic lesions occur in the orbit, after trauma or retrobulbar injections.

Neoplasia affects the lacrimal gland, the optic nerve, the nasal sinuses and glioma (neurofibromatosis) (Fig. 36.6), meningioma and osteoma (Fig. 36.7).

Dysthyroid exophthalmos (Fig 36.8, Fig. 36.9 and 36.10). Often unrelated to active thyroid disease .but can start after thyroidectomy and may need urgent tarsorrhaphy, large doses of steroids or even orbital decompression, if the eyeball is threatened by exposure. This is most easily done into the nasal sinuses (Chapter 44). CT and magnetic resonance imaging (MRI) scans are useful in diagnosis.

   Pseudotumour, or malignant lymphoma.

  Haemangiomas of the orbit (Fig. 36.11).

Tumour secondaries or metastases. These are rare. In children they usually come from neuroblastoma of the adrenal gland, whereas in adults, the oesophagus, stomach, breast and prostate can be sites of primary lesions.

Diagnostic aids

Diagnostic aids include: radiography, tomography, orbital venography, ultrasonography, CT and MRI.

Treatment

Treatment is directed to the cause of the lesion if at all possible, taking care to prevent exposure of the eye and discomfort from diplopia.