Orbital tumor

It is an anatomical region located around the eyeball, delimited by a bony framework in which numerous bones participate. It includes 7 muscles, the lacrimal gland, the eyeball and its optic nerve. All of these tissues are surrounded by orbital fat, itself traversed by vessels and nerves.

It is an abnormal process in its location and nature. This tumor can be benign or malignant. The tumor can develop from a structure of the orbital component (bone, fat, muscle, vessels, nerve), or secondary to metastases. Some grow slowly and go unnoticed while others can grow quickly.

A malignant tumor is a cancer, that is to say a tumor composed of cells multiplying in an anarchic fashion, invading and destroying surrounding structures. It is likely to swarm at a distance in other organs, constituting metastases. The malignant tumor therefore carries a vital risk.

In children, the most common orbital tumors are dermoid cysts and hemangiomas. In adults we find cavernous hemangiomas, orbital metastases and orbital lymphomas.

• - A displacement of the eyeball pushed back according to the position of the tumor, diplopia or double vision (interaction of the tumor with the muscles), a decrease in visual acuity or impairment of the visual field (if the optic nerve is affected), redness, swelling, more or less painful inflammation of the orbital region, skin changes.

• - The palpation or line of sight of an expansive process filling in the hollows above or below the eyelids, or between the eyeball and the eyelids.

These are mainly radiological examinations: CT scan and / or nuclear magnetic resonance imaging (MRI) are in the vast majority of cases essential.

Orbital ultrasound can also be done.

At the end of these examinations, the comparison of the clinical examination and the radiological characteristics will allow in more than 50% of the cases to have a fairly precise idea of the diagnosis.

However, this diagnosis will only be confirmed by direct analysis of a sample (this is the biopsy) or of the entire tumor.

Sometimes your ophthalmologist will not find it necessary to perform this biopsy. Indeed, if the clinical and radiological signs are sufficiently characteristic of a lesion.

The intervention is made necessary to know the exact nature of your tumor, to treat it, and to prevent regional and / or general spread.

Orbital surgery is delicate and must be performed by an oculoplastic surgeon specializing in the orbit. To understand the delicacy and difficulty of the gesture, the tumor must be eradicated from the orbit which represents a solid cone narrow in depth and which is 30 cm3 with a noble and fragile structure in its center, it is the eyeball (7 cm3 ).

Any irreversible injury to the optic nerve and its vasculo-nervous pedicle must be avoided. All the difficulty will therefore depend on the location of the tumor :

A previous tumor will usually be easily cleared. The incision is usually located in a skin area that can be camouflaged : eyelid fold, eyebrow ... There are also approaches which are not cutaneous but conjunctival without visible external scar (the conjunctiva is the mucous envelope that covers the eyeball and the posterior surface of the eyelids).

To access a more posterior tumor, that is to say more at the bottom of the orbit, we can perform an osteotomy (remove part of the bone from the outer walls of the orbit and put it back at the end of the intervention) which will allow a good exposure of the orbit particularly the external region and behind the eye. The incision for this approach will always be hidden at the level of the eyelid crease.

A scar-free conjunctival incision can also be made for deep tumors.

All of these interventions are done under general anesthesia except sometimes for small anterior tumors. Hospitalization time is usually quite short for small anterior tumors, but can be a few days, or two to three days for very complicated cases.

Usual postoperative course After a transient phase of inflammation and hematoma, your orbital region returns to a normal appearance. The skin threads will generally be removed on day 7 after the operation.

The final diagnosis established by the pathologist will be made after a few days. In the event of a malignant tumor, additional treatment after surgery (radiotherapy and / or chemotherapy) will be discussed in a multidisciplinary meeting (with other doctors specializing in oncology). Its purpose is to reduce the risk of local tumor recurrence, and the risk of metastases occurring.

Some tumors have more specific treatment : some vascular tumors can be treated by an eyelid and orbit surgeon who will search for the tumor and inject a sclerosing product (sclerotherapy) which will melt the tumor. In rare cases, it is necessary to take charge of a specialist radiologist. This embolises the tumor, ie closes the vascular malformation to make it regress. To do this, the radiologist takes a vascular probe to access the malformed site and deposit the embolizing substances there.

Complications are rare. It can be either :

• - From a hematoma : you should know that the day after the intervention the eyelids are swollen with a more or less important part of inflammation. All of this is generally transient and regressive. Sometimes the surgical bleeding is more important and the surgeon may have to place a drain that comes out of the skin and which will be removed 2 to 3 days after the operation.
• - From an infection : like any surgery, orbital surgery can be the source of infections. Antibiotic coverage during and after surgery is systematic and makes this type of complication rare.
• - Diplopia (double vision) due to the intraoperative manipulation of the oculomotor muscles; it is generally rapidly regressive; otherwise, it can be compensated by prisms or by surgery later.
• - A decrease in visual acuity by suffering from the optic nerve for example by an orbital hematoma too important. An intraoperative injury to the optic nerve in the event of an adjacent tumor may also be the cause of this loss of visual acuity. Occlusion of the retinal vessels is rare but possible.