What are skull base tumors?

Skull base tumors are rare lesions that form at the base or floor of the skull. They may pose a challenge in management due to their location, being difficult to assess. he skull base is complex because every nerve in the body that carries signals to and from the brain crosses the skull base. Additionally, the large blood vessels that carry blood to and from the brain run through the skull base. Managing these lesions require great skill and additional specialized training.

The estimated incidence of skull base tumors globally is less than 1 per 100 000 of the population.  

Where do they originate from?

Skull base tumors can originate from any normal tissue and structures found primarily in the area. Primary skull base tumors classically originate in the skull bone, paranasal sinuses, ear structures, nerves, blood vessels, and even the covering sac of the brain ( meninges).

They may also originate elsewhere in the body and then spread to the skull base. When cancerous this is referred to as metastasis. In some cases, a skull base lesion may be part of a systemic condition such as an infection, blood disorder, or other diseases.

Skull Base

The presentation of skull base tumors

Unfortunately, a skull base tumor usually presents late. Symptoms vary from nasal complaints such as the blocked nose, bleeding, headache, loss of smell to eye symptoms such as double vision, loss of vision, and swelling of the eye. If the ear structures are involved hearing loss, dizziness, pain, noise in the ear, discharge from the ear may be present. With neurological involvement neurological symptoms such as hoarseness, swallowing difficulty, and speech problems may be present.

How are skull base tumors investigated?

After a physical examination, the diagnosis is made by a computed tomography (CT ) scan which focuses on the bony aspects of the skull base, and magnetic resonance imaging (MRI) scan which concentrates on soft tissue. Other tests like angiography, blood tests, hearing, and balance tests might also be needed.

The management of skull base tumors

Each patient is assessed and then the best treatment option is discussed with the patient and our local head and neck forum. The treatment options may vary from observation (no immediate treatment but follow up surveillance with clinical examination and scans) to radiotherapy (with or without chemotherapy), surgery, or even combination therapy.

 

The surgical approaches to these tumors are from underneath or from the side and in some instances even a combination of the two. Bone and soft tissue are removed or moved to expose the tumor. Thus, the tumor can be exposed with little or no brain retraction. The approach might be through the bone of the ear (lateral skull base) like the trans-temporal or Fisch approach, through the nose or paranasal sinuses (endoscopic, trans-ethmoidal or trans-sphenoidal), from the neck (trans-cervical), or the eye (trans-orbital, orbital-zygomatic or craniofacial).

 

The location of skull base tumors is often close to critical areas (brain, blood vessels, or nerves). This makes the surgery difficult. The monitoring of nerves is usually done in the operating theatre by a neuro-physiologist.

 

A variety of benign tumors such as paragangliomas (glomus tumors), meningiomas, acoustic neuromas, and angiofibromas are treated with surgery utilizing the above approaches. Many malignant tumors are also managed by these approaches and include squamous cell carcinoma (SCC), esthesioneuroblastoma, chondrosarcoma, sarcoma, chordoma, and other malignancies.

Rehabilitation after surgery

Rehabilitation after surgery plays an important role in the management of skull base tumors. Physiotherapy, speech, voice and language therapy, swallowing therapy, dietary consideration, occupational therapy, hearing restoration, and balance rehabilitation can be offered to patients to improve and maximize their quality of life.

To request a consultation

Dr. Moolman has vast experience in managing these conditions. To book an appointment visit our contact page