An osteoma is a benign growth that is most commonly found in the skull when new bone grows on old bone or on tissue.

When an osteoma grows on bone it is called a homoplastic osteoma and when it grows on tissue it is called a heteroplastic osteoma. The cause of osteoma is not known, but they have been linked to trauma and also to infection.

Osteoma is also a symptom of Gardner’s syndrome. Large tumors can cause pain, headaches and severe and recurring sinus infections. While most of the tumors are slow growing and present no symptoms, severe complications can occur as a result of the tumor compressing other areas in the skull.

There are two main types of osteoma – compact and spongy. A compact osteoma is made up of bone and a spongy osteoma is made up of bone with bone marrow.

Signs & Symptoms

Since osteoma are such slow growing benign tumors they often show no signs or symptoms. When they begin to grow larger they can start to affect a person’s vision and hearing. They can physically make a person’s eye bulge out of their eye socket.

The tumors can also compress nerves and get in the way of things functioning properly. Sinus infections and other problems associated with the sinuses are common. As the osteoma grows patients may begin to experience general pain or headaches. At first pain caused by osteoma can come and go, but after awhile it becomes more constant.

Diagnosis

An osteoma is usually discovered by x-ray. The cells are tested and looked at under a microscope.

Treatment

An osteoma is generally only treated if and when it becomes a problem. They can be surgically removed using a type of surgery called endoscopic endonasal approach (EEA) that uses the nasal passages’ natural opening to perform minimally invasive surgery.

Prognosis

Since osteoma is such a slow-growing cancer it can sometimes be managed for many years with just pain medication. If they are removed surgically the prognosis is quite good. In approximately 10% of the cases they do recur after three to seven years.