The orbit (otherwise known as the eye socket) is the bony cavity that contains the eyeball. Orbital tumors are abnormal growths of tissue within the orbit. They may begin in any of the tissues within the orbit, including nerves, blood vessels, connective tissue, and bones. The tumors can also form in nearby tissues and extend into the orbit as they grow. Symptoms can include eye bulging, pain, double vision, decreased vision, and, in some cases, vision loss in the affected eye.

Orbital tumors are rare. Around two-thirds of them are benign (noncancerous) and one-third are malignant (cancerous). Of those that are malignant, approximately 1% to 3% are orbital metastases, meaning they develop when cancer cells from another part of the body spread through the bloodstream to the orbit and form a tumor.

Orbital tumors can affect both males and females, and they can occur in children and adults. However, the types of orbital tumors that most commonly affect children differ from those that are most common among adults.

Treatment for orbital tumors may include observation (for benign tumors that do not cause symptoms), surgery, radiation therapy, chemotherapy, immunotherapy, and targeted therapy—or a combination of two or more of these treatments.

The orbit, or eye socket, is a bony cavity at the front of the skull that houses various important structures, including the eye, muscles, nerves, blood vessels, connective tissue, and the lacrimal gland. Each of these components plays an important role:

• The muscles, technically known as extraocular muscles, are responsible for eye and eyelid movement.
• The nerves carry signals to and from the brain, including pain signals and signals that control the extraocular muscles, among others. At the back of the eye, the optic nerve carries visual messages to the brain, which converts these signals into images.
• The blood vessels supply blood to the eye and other tissues in the orbit, allowing them to work properly and stay healthy.
• The connective tissues support and protect the eye and other tissues in the orbit.
• The lacrimal gland secretes fluid—tears—that protects, lubricates, and cleans the surface of the eye.

The bony structure that forms each orbit is made up of seven bones that protect the eye and provide structural integrity to the tissues within the orbit.

Orbital tumors can arise from any of these components, impairing their ability to function normally.

Tumors located within the orbit are known as orbital tumors. They are broadly classified into three subgroups:

• Primary orbital tumors begin in one of the tissues within the orbit. They can form from cells in any of the structures within the orbit. Primary tumors may be benign or malignant.
  • Benign tumors are noncancerous and cannot spread to other parts of the body.
  • Malignant tumors are cancerous and can invade nearby tissues and spread to distant parts of the body.
• Secondary orbital tumors. Secondary orbital tumors occur when tumors in neighboring structures, such as the eyelid, eye, bone, conjunctiva (the thin membrane that covers the inner surface of the eyelid and the sclera, the white part of the eye), and paranasal sinuses (hollow, air-filled spaces in the bones around the nose), among others, extend into the orbit. Secondary orbital tumors may also be benign or malignant.
• Metastatic orbital tumors. Metastatic orbital tumors occur when cells from a primary cancerous tumor in one part of the body spread through the blood to the orbit, where they form a new cancerous tumor. Though the new tumor is located in the orbit, the cancer is the same as the site where it began. For instance, if cells from lung cancer spread to the orbit and form a tumor, the tumor cells in the orbit are lung cancer cells. Breast cancer, prostate cancer, melanoma, and lung cancer are the most common types of cancer to spread to the orbit.

Orbital tumors may be further categorized based on a number of characteristics, including the type of tissue from which they began (e.g., blood vessels, nerves, etc.) and their location within the orbit.

Some types of benign orbital tumors include:

• Capillary hemangioma (the most common benign orbital tumor in children). This tumor develops from blood vessel tissue.
• Cavernous hemangiomas. These are the most common benign orbital tumors in adults. They develop from blood vessel tissue.
• Lymphatic malformations (also known as lymphangiomas) generally occur during development in the womb. They form from the tissue of lymph vessels.
• Meningiomas develop from the meninges, the membranes that surround and protect the brain and spinal cord.

Some types of malignant orbital tumors include:

• Rhabdomyosarcoma (the most common primary malignant orbital tumor in children. In the United States, rhabdomyosarcomas make up approximately 40% of pediatric orbital tumors. Rhabdomyosarcomas develop from cells that develop into muscles)
• Lymphoma (ocular adnexal lymphoma is the most common primary malignant orbital tumor in adults)
• Lacrimal gland carcinomas
• Osteosarcoma

Some types of secondary orbital tumors include:

• Cancers of the eyelid (such as basal cell carcinoma and squamous cell carcinoma)
• Cancers of the conjunctiva
• Uveal melanoma (cancer that affects cells in the uvea, a part of the eye)
• Retinoblastoma
• Brain tumors

There are many other types of primary benign and malignant orbital tumors.

The exact cause of different orbital tumors is specific to that tumor type. Explanations can include a developmental abnormality, genetic mutation, proliferation of abnormal or normal cells, or other unknown causes.

Tumors may form in the orbit in the following ways:

• Orbital tumors can form from any of the tissues and structures within the orbit.
• Cancer cells from elsewhere in the body can also spread to the orbit, where they form tumors.
• Tumors that form in tissues close to the orbit may expand into the orbit as they grow larger.

Symptoms of orbital tumors vary based on their location, size, and type of tumor.

The orbit is a confined space. When a tumor forms within this space, it can grow large enough to press against nearby structures, impairing their function or damaging them, thereby resulting in a range of symptoms. For example, a tumor can press against the eye, nerves, blood vessels, and/or muscles within the orbit.

Common symptoms of orbital tumors include:

• Outward bulging of the eye (known as proptosis, when the tumor presses against the eye, pushing it outward)
• Pain around the eye
• Double vision
• Decreased visual acuity
• Loss of vision
• Swelling (edema) of the eyelid
• Droopy eyelid (known as ptosis)
• Difficulty or inability to move the eye in certain directions

To diagnose orbital tumors, doctors will review your medical history, perform an eye exam, and order one or more diagnostic tests.

Your primary care physician or another health care provider may perform an initial physical exam that includes an examination of your eye and the area around it. Based on the findings of their initial exam, they will typically refer you to an oculoplastic surgeon, a medical doctor who specializes in the orbit, for diagnosis and treatment.

The oculoplastic surgeon will ask you about your symptoms, including when they began and whether they have worsened over time. The oculoplastic surgeon will conduct a complete exam to check for signs of an orbital tumor. During the exam, the oculoplastic surgeon may assess your visual acuity and eye movement, and use a slit lamp (a microscope equipped with a light) to examine your eyes in detail.

Additional tests are necessary to make the diagnosis. These may include:

• Imaging studies. Computed tomography (CT) and magnetic resonance imaging (MRI) scans allow doctors to visually assess the location and extent of the tumor. Ultrasound may also be used to make a diagnosis.
• Biopsy. In this procedure, a small piece of the tumor is collected for analysis. In most cases, this test involves removing a tissue sample via an incision on the skin. The sample is sent to a laboratory for analysis by a pathologist. The pathologist will examine the tissue sample under a microscope to determine the type of tumor, including whether it is benign or cancerous.
• Other tests. If the doctor suspects certain types of cancer, additional tests, such as blood work or bone marrow tests, may be ordered.

Treatment of orbital tumors is based on the type of tumor and its characteristics, as well as the patient’s general health and treatment preferences.

Treatments for benign orbital tumors include:

• Observation. Observation via serial exams may be recommended for people with benign orbital tumors that do not cause symptoms.
• Medication. Most benign orbital tumors are not treated with medications, though some types of tumors may respond to certain medications, such as beta blockers.
• Surgery. Surgical removal of the tumor or part of it (if the entire tumor cannot be removed) is generally a possibility for the right candidate.
• Radiation therapy. In general, radiation therapy is not used to treat benign orbital tumors. However, it may be used to treat tumors that cannot be surgically removed or tumors that return after treatment.

Treatments for malignant orbital tumors include:

• Chemotherapy. Chemotherapy drugs kill or damage cancer cells, thereby stopping or slowing their growth.
• Immunotherapy. This treatment involves using drugs to stimulate the patient’s immune system, improving its ability to fight the cancer.
• Targeted therapy. In this treatment, the cancer is treated with drugs targeting specific cancer cell components that are not found in noncancerous cells.
• Surgery. Surgery may involve removing the entire tumor or, in cases in which the entire tumor cannot be removed, part of it to reduce its size. Surgically reducing the size of the tumor is known as debulking.
• Radiation therapy. High doses of radiation are used to kill or damage cancer cells, preventing them from growing and spreading.

Often, two or more treatment options are used in combination to treat orbital tumors.

The outlook varies based on a number of factors, including the type of tumor, its location, and the timing of the diagnosis.

In general, the outlook is good for people with benign orbital tumors. Early diagnosis and treatment can help prevent or reduce vision changes and complications due to damage to nearby tissues caused by the tumor.

The outlook for malignant orbital tumors depends on several factors, such as their histologic grade (characteristics of the cancer cells, including how abnormal they are and how quickly they are likely to spread), the stage of the cancer when it is diagnosed, and the type of cancer. Outcomes are usually best when the cancer is diagnosed and treated early.

“What sets Yale apart in the treatment of orbital tumors is its unparalleled integration of cutting-edge research and multidisciplinary care,” says Michelle M. Maeng, MD, a Yale Medicine oculoplastic surgeon. “Our approach combines innovative diagnostics, state-of-the-art surgical techniques, and personalized treatment plans crafted together by experts in oculoplastic surgery, head and neck surgery, neurosurgery, oncology, radiation therapy, interventional neuroradiology, and others. At Yale, we don’t just treat the tumor—we care for the whole patient, offering compassionate support and delivering outcomes that redefine excellence.”