Orbital tumours develop in the tissues and structures around the eyeball. The orbit is made up of bony and connective tissue components. Most adults who develop orbital tumours are in their 60s and 70s.
People can have benign tumours or inflammatory diseases of the orbit, as well as malignant tumours. Primary malignant tumours of the orbit are uncommon.
The most common malignant orbital tumours in adults include:
- most common type of malignant orbital tumour in adults
- occurs mainly in the lacrimal gland, but can occur in other orbital structures
- sarcoma – almost any type of sarcoma can involve the orbit
- optic nerve glioma
- extremely rare tumour that begins in the optic nerve and spreads to the orbit
Malignant orbital tumours can also be secondary cancers that have spread to the orbit from nearby structures, such as the eyeball (intraocular tumours), eyelid, conjunctiva, sinuses or nasal cavity.
Cancers from other parts of the body, such as the breast, lung, prostate, brain and kidney, can also spread (metastasize) to the orbit. Melanoma skin cancer can also spread to the orbit, but this is not common.
Rhabdomyosarcoma is the most common orbital tumour in children.
The orbit is a small area. Tumours in the orbit can put pressure on the other structures within the eye, which can cause:
- bulging or protrusion of the eye (called proptosis) – the most important sign
- vision changes (such as double vision, blurred vision or vision loss)
- abnormality of the pupil
- changes to eye muscle function
- pain (due to cancer in the orbital bone or nerves)
Many of the same tests used to diagnose and stage any type of eye cancer are also used to diagnose and stage orbital tumours.
- medical history and physical examination
- Physical exam includes a complete eye examination, neurologicalneurologicalHaving to do with nerves or the nervous system. examination and feeling the lymph nodes around the ear, lower jaw and in the neck (regional lymph nodes).
- ophthalmic ultrasound
- computed tomography (CT) scan of the orbit
- magnetic resonance imaging (MRI) of the orbit
- MRI is also used to look for lymphoma in the brain or meningesmeningesThe membranes that cover and protect the brain and spinal cord..
Grading is a way of classifying orbital tumour cells based on their appearance and behaviour when viewed under a microscope.
The grade of orbital sarcoma is based on how different cancer cells look and act compared with normal cells (differentiation) and their rate of growth. The grading system used is the same as for some other types of eye cancer.
The grade of orbital lymphoma is based on how slowly or quickly the orbital lymphoma is growing and how it is likely to behave.
Staging is a way of describing or classifying a cancer based on the extent of cancer in the body.
The most common staging system for sarcoma of the orbit is the TNM system. The International Union Against Cancer (UICC) uses the TNM system to describe the extent of many solid tumour cancers. Staging for orbital sarcoma applies to cancers that start in the orbital bone or soft tissues and is listed below.
Orbital lymphoma is staged as a non-Hodgkin lymphoma.
TNM stands for tumour, nodes, metastasis. TNM staging describes:
- the size of the primary tumour
- the number and location of any regional lymph nodes that have cancer cells in them
- whether the cancer has spread or metastasized to another part of the body
Primary tumour cannot be assessed
No evidence of primary tumour
Tumour is 15 mm (0.6 inch) or less in size.
Tumour is more than 15 mm in size. It has not spread into the globe of the eye or the bony wall of the orbit.
Tumour is any size and has spread into the orbital tissues or bony walls of the orbit.
Tumour has spread into one or more of the following:
Regional lymph nodes cannot be assessed
No regional lymph node metastasis
Regional lymph node metastasis
Note: Regional lymph nodes include those around the ear (preauricular nodes), lower jaw (submandibular nodes) and neck (cervical nodes).
No distant metastasis
There is no stage grouping for orbital sarcoma.
Recurrent orbital sarcoma
Recurrent orbital sarcoma means that the cancer has come back after it has been treated. It may recur in the same location as the original cancer or it may recur in another part of the body (metastatic orbital sarcoma).
The prognosis for orbital tumours depends on the type and the extent of the tumour. Most malignant orbital tumours tend to grow into (infiltrate) nearby structures.
Treatment for primary orbital tumours often involves surgery. However, surgery for orbital tumours is difficult to perform because of the limited space in the orbital area.
- Surgery on the orbit of the eye is called an orbitotomy. The surgical approach used depends on the location and size of the tumour.
- The surgeon will try to preserve the eye (ocular preservation) whenever possible.
- Enucleation or orbital exenteration may need to be done for more extensive tumours.
- External beam radiation therapy or chemotherapy may be an option after surgery, depending on the particular type of orbital tumour.
Treatment of secondary orbital tumours that have spread into the orbit from nearby structures depends on the location of the original tumour.
- Surgery is often used, but this depends on the extent of the cancer.
- Metastatic tumours to the orbit may be treated with external beam radiation therapy if they cannot be removed by surgery.
- Chemotherapy or hormonal therapy may also be an option, depending on the primary site.