What is Benign Orbital Tumors?
The orbit, or eye socket, contains many vital parts of the eye. Any mass or growth in this compact area can cause serious vision problems very quickly, even total loss of vision. These masses could be caused by cancer, inflammation, or infection. This article will talk about non-cancerous growths in the eye socket in adults, discussing how common they are, how they develop, how they are diagnosed, and how they are treated.
Although they are sometimes mentioned in discussions about eye socket tumors, tumors of the tear gland, the inside of the eye, and tissues around the eye are not covered in this article. In addition to understanding a patient’s medical history, knowing how common these tumors are and what increases the risk of them can help speed up further tests and diagnosis of eye socket tumors.
The orbit is a small, well-defined space. The eye sockets are usually symmetric, with walls on the inside that are parallel to each other, coming to a point at the back. The bones that make up the inside wall of the orbit are the ethmoid, lacrimal, maxillary, and the lesser wing of the sphenoid bones. The thinnest part of the orbit, which separates this area from the ethmoid sinuses, is the lamina papyracea.
The roof of the orbit is composed of a part of the frontal bone and the lesser wing of the sphenoid bone. It contains the tear gland fossa, the trochlear fossa, and the supraorbital notch or foramen.
The thicker wall on the outside of the orbit is composed of the zygomatic bone and the greater wing of the sphenoid bone. This wall extends in front of the globe of the eye, allowing for vision in the temporal field. The outside wall features include the lateral Whitnall tubercle, Whitnall ligament, and frontozygomatic suture.
The bones that make up the floor of the orbit are the maxillary, palatine, and zygomatic bones. The maxillary division of the trigeminal nerve and the infraorbital artery are situated along the infraorbital groove and canal. The optic canal, superior orbital fissure, and inferior orbital fissure contain important nerves and blood vessels of the orbit. The main artery that supplies blood to the orbit is the ophthalmic artery, which is a branch of the internal carotid artery. There are also communicating branches with the external carotid artery which form a network to further provide blood to the region around the orbit. The superior and inferior ophthalmic veins are responsible for draining blood from the orbit.
Therefore, any masses in the orbit can cause a range of cosmetic and functional problems based on their location and size. Knowing the anatomy of the orbit and using careful imaging techniques is crucial in properly diagnosing and managing these tumors.
What Causes Benign Orbital Tumors?
Certain tumors can originate in different types of tissue that make up the eye socket or orbit. Here’s a simple compilation of these tumors:
– Cystic tumors: These include epidermoid cyst, dermoid cyst, mucocele, hematic pseudocyst, meningoencephalocele, apocrine hidrocystoma, and colobomatous cyst.
– Vasculogenic tumors: These grow from blood vessels and include cavernous hemangioma, lymphangioma, orbital varix, and capillary hemangioma.
– Neural tumors: These tumors originate from nerves and include schwannoma, neurofibroma, optic nerve glioma, and paraganglioma.
– Tumors that develop from fibrous or connective tissue and cysts, such as fibrous histiocytoma, giant cell angiofibroma, and myofibroma.
– Osseous and fibro-osseous tumors: You’ll find these from bone or fibrous bone tissue – like fibrous dysplasia and osteoma.
– Lipomatous tumors: These arise from fat tissue and include dermolipoma and lipoma.
– Lymphoid tumors: These types grow from lymph tissue and include plasmacytoma and benign reactive lymphoid hyperplasia.
Moving on to a more detailed discussion, we take a look at cystic tumors. Epidermoid cysts are a rare type of cysts that form in the orbit but they need to be considered when deep orbital cystic lesions are detected. They are different from dermoid cysts, which contain mesodermal elements and are usually found in children.
Mucoceles are cavities filled with sterile mucus, forming due to blocked frontal and ethmoidal sinuses. They grow slowly but can cause symptoms similar to those seen in other orbital masses if they grow large enough. Then, there are hematic pseudocysts which occur rarely but present as a sudden protrusion of the eye following remote trauma.
Next, we have vasculogenic tumors that arise from blood vessels. The cavernous hemangioma is the most common benign primary orbital tumor in adults. Lymphangiomas involve both the blood vessels and the lymphatic system. Orbital varices usually present with intermittent bulging of the eye or double vision during activities that increase pressure in the abdomen and chest like coughing.
Next are the neural tumors that arise from nerves. Schwannomas, also known as neurilemomas, are tumors of the peripheral nerve sheath. Neurofibromas are another peripheral nerve sheath tumor often associated with a genetic disorder called Neurofibromatosis.
Fibrocystic tumors can arise from connective tissue within the orbit. In adults, the most common type is a fibrous histiocytoma. While it’s often harmless, it does have
Risk Factors and Frequency for Benign Orbital Tumors
Primary orbital tumors, which occur in the eye socket, are quite rare, affecting around 1 in 100,000 people. Most of these tumors are benign or non-cancerous. However, people over age of 60 have a higher risk of these tumors being malignant or cancerous. In terms of gender, men and women are diagnosed with these benign orbital tumors equally. However, certain types like cavernous hemangiomas and meningiomas of the optic nerve sheath and sphenoid wing, are more frequent in women. It’s useful to note that at present, there is no evidence to suggest geographical location or race increase the risk of developing these tumors amongst adults.
- In a large study of 2,480 orbital lesions, benign masses were found in 68% of the cases.
- The most common ones were dermoid cysts (14%), followed by cavernous hemangiomas (9%).
The location of the tumor in the eye socket can hint at what kind of tumor it might be. In the upper outer part of the eye socket, dermoid cysts are the most common, while most tumors found in the upper inner part were mucoceles. In the lower outer part, cavernous hemangiomas were common while in the lower inner quadrant, the highest number were basal cell epitheliomas. It’s also worth noting that tumors in the lower inner quadrant often indicated a higher likelihood of the disease being malignant.
In the central part of the eye socket, the most common masses found were meningiomas.
Signs and Symptoms of Benign Orbital Tumors
Orbital tumors, or masses in the eye socket, can cause a range of symptoms. Common signs include bulging of the eye, difficulties in eye movement, swelling of the eye, damage to the eye’s surface, and nerve damage. People often experience eye and surrounding area pain, vision loss, double vision, changes in the eye or eyelids’ appearance, throbbing, irritation, or in rare cases, a visible lump. Slow-growing tumors usually don’t cause pain. However, if the tumor suddenly changes, like through a burst or bleed, this can cause sudden pain and other symptoms.
If doctors suspect an orbital tumor, they will likely recommend a series of eye tests such as:
- Checking vision sharpness and focus for any asymmetry or changes.
- Pupil assessment in various gaze directions to check for defects and optic nerve compression.
- Color vision tests to check for subtle optic nerve damage.
- Checking eye pressure to screen for high pressure due to the mass or impaired venous drainage.
- Testing eye movement to check for restrictive or paralytic muscle limitations.
- Measurement of proptosis (bulging of the eye) for future reference.
- Detailed examination of the back of the eye to check for optic nerve asymmetry, pallor, and choroidal folds.
- Optical coherence tomography (OCT) and Humphrey visual field (HVF) tests to further assess and quantify the degree of optic nerve damage.
Here are common signs and symptoms of orbital tumors and possible reasons why they occur:
- Decreased vision sharpness: Could be due to nerve damage due to compression, eye surface disease, or glaucoma.
- Orbital pain or numbness: Might be caused by mass effect, rapid expansion, nerve compression.
- Swollen eyelid: May be due to inflammation, impaired venous outflow.
- Chemosis (swelling of the conjunctiva): May be a result of impaired venous outflow or inflammation along the surface of the eye.
- High eye pressure: Might be a direct mass effect or secondary tissue swelling with increased pressure around the eye, increased episcleral or pressure in the veins of the eye socket, or rarely secondary angle closure (a type of glaucoma).
- Bulging eye: Could be due to the mass effect causing anterior displacement of the eye.
- Eye displacement: Might be due to the mass effect causing upward displacement of the eye.
- Double vision: Could be due to the mass effect causing displacement of the eye or adhesion to the eye, restrictive or paralytic muscle limitation, symptomatic difference in refraction (focal power) between the eyes.
- Changing eyesight to hyperopia: Might be due to the mass effect causing flattening of the back of the eye and decreased length along the eye’s axis.
- Drooping eyelid: Could be due to the mass effect, neuropathy, changed place of the eye.
- Gaze-evoked amaurosis (vision loss upon looking certain directions): Could be due to gaze-dependent optic nerve compression.
Testing for Benign Orbital Tumors
Orbital tumors, which are growths in the eye socket, can often appear similar and present the same symptoms. While patient history and physical examination can sometimes hint at the type of orbital mass, imaging tests are usually required to confirm a diagnosis. These medical tests help doctors determine the nature of the mass and plan appropriate treatment.
Computed tomography (commonly known as a CT scan) or magnetic resonance imaging (MRI) are key tools that can deliver important information for diagnosis. A CT scan, which uses X-rays to develop a detailed picture of the body, is often the first imaging test performed to assess the position and characteristics of the orbital mass and the surrounding bone structures. It becomes even more helpful when contrast dyes are used. These dyes are injected into the body to highlight certain tissues before taking the scans. This helps doctors distinguish between different types of masses.
In some cases, when a more thorough and detailed view of structures in the body is needed, MRI scans are used. MRI, which uses a magnetic field and radio waves to produce detailed images, is performed with and without contrast for maximum clarity. Ultrasound imaging, while less common, can provide quick diagnostic information, particularly for masses situated in the front part of the eye socket.
Treatment Options for Benign Orbital Tumors
If you have a benign (noncancerous) mass in the eye socket area, your treatment plan often depends on whether or not you’re experiencing symptoms caused by the mass. For smaller signs or symptoms, doctors may just monitor the mass with annual check-ups. However, masses that have a high risk of becoming cancerous are exceptions and would need prompt action.
Most benign masses in the eye socket area can’t be treated with medication. However, some severe types of masses, known lymphatic malformations and lymphangiomas, have reportedly responded to certain drugs like Sildenafil and Sirolimus.
Surgery is typically recommended for eye socket masses that cause symptoms, especially changes in vision, a bulging eye, or restrictions in eye movement. Some types of masses, including lymphangiomas and incompletely removed cavernous hemangiomas, may have a high risk of regrowth after surgery. Meanwhile, hemangiopericytomas, although a rare type of tumor, should be removed surgically due to their potential risk of becoming cancerous.
Certain eye socket masses, such as orbital varices and tumors that grow around the optic nerve sheath, are hard to remove surgically because of their potential to bleed excessively and their proximity to vital structures in the eye. However, a procedure known as embolization, usually performed by an interventionist radiologist, can help decrease the risk of bleeding and enable safer surgical removal of such masses.
Radiation therapy, which uses high-energy particles to destroy tumor cells, is not usually used alone to treat benign eye socket masses. However, it can sometimes be used alongside other treatments to manage tumors that cannot be removed surgically or that might regrow after surgery, such as schwannomas and sphenoid wing meningiomas.
For lesions or tumors located at the orbital apex – the furthest part of the eye socket – surgical removal can be particularly challenging due to its complex anatomy. These lesions can put pressure on the optic nerve, causing progressive, permanent vision loss. In some cases, a procedure known as orbital decompression can be used to relieve pressure and preserve vision, without the need for complete tumor removal. This procedure can often be a safer option compared to a complex surgery in this part of the eye socket.
What else can Benign Orbital Tumors be?
There are several conditions that can look similar to orbital tumors based on their symptoms. These can be grouped into three main categories: infectious diseases, inflammatory diseases, and other conditions to consider.
The infectious diseases include:
- Orbital cellulitis
- Orbital tuberculosis
- Orbital sarcoidosis
- Histoplasmosis
- Coccidioidomycosis
- Mucormycosis/zygomycosis
The inflammatory diseases include:
- Thyroid orbitopathy (also known as thyroid eye disease)
- Idiopathic orbital inflammation (IOI)
- IgG4-related disease
- Amyloidosis
- Giant cell myositis
- Optic neuritis
Other conditions to consider are:
- Orbital fat prolapse
- Lacrimal gland prolapse
- Orbital metastasis
What to expect with Benign Orbital Tumors
The outlook for non-cancerous tumors located around the eye (known as benign orbital tumors) is generally good. However, this can change based on factors like where the tumor originates and where exactly it’s located. One of the main long-term problems associated with these tumors is the effect they can have due to the space they take up, especially if they’re near vital parts like the optic nerve (which connects the eye to the brain).
Some benign orbital tumors may be small and found by accident during a routine doctor’s visit, and others may not cause any problems for a long time (this is what we mean when we say they have an ‘indolent course’). However, if certain tumors grow big enough, they can cause a range of issues like proptosis (bulging eyes), direct pressure on the eyeball, optic neuropathy (damage to the optic nerve), or diplopia (double vision) caused by restriction to the muscles controlling eye movement. In addition, the location of the tumor and how close it is to important structures has a significant impact on the vision outlook.
As an example, when it comes to optic nerve sheath meningiomas (tumors that grow from the protective layers around the optic nerve), surgery is often avoided because there is a risk of blindness after the operation.
Possible Complications When Diagnosed with Benign Orbital Tumors
The issues and complications that arise from benign (non-cancerous) orbital tumors, or tumors in the eye socket, come about mainly because they take up space in the eye socket. Some blood vessel tumors, like orbital varices, can cause sudden bleeding in the eye socket. Surgery to take a biopsy or to remove these eye tumors can lead to bleeding in the eye socket or injury to important nearby structures.
The complications that can happen after surgery can vary. It depends on the kind, size, and where in the eye socket the tumor is. If some types of orbital tumors, like cavernous hemangiomas, are not completely removed, they can come back.
Main Problems of Benign Orbital Tumors:
- Taking up too much space in the eye socket
- Potential sudden bleeding in the eye socket (in the case of certain blood vessel tumors)
- Bleeding in the eye socket from surgery
- Injury to vital structures near the tumor because of surgery
- Possibility of tumor recurrence if not completely removed during surgery
Preventing Benign Orbital Tumors
The early signs of a non-cancerous eye tumor can be similar to symptoms from a variety of other illnesses, like inflammation, infections, or even malignant (cancerous) eye diseases. So, when a doctor is trying to diagnose the condition, it’s important that they communicate with the patient in a careful and understanding manner. In situations where there’s a small tumor that’s not causing any symptoms, doctors may discuss the option of simply monitoring the condition and the importance of the patient returning for regular check-ups.
If treatment is necessary, doctors should thoroughly explain the potential risks and benefits of the procedure, as well as any other possible options. This is to ensure the patient can make an informed decision about their health care. Remember, it’s important to adhere to your follow-up appointments and to discuss any concerns or questions you might have with your doctor.
