Skull base
Skull base tumors
This section contains information on the following:
1. What are they?
2. Investigations
3. Treatment
1. What are skull base tumors?
These tumors are broadly divided into those that involve the anterior and lateral skull bases. The anterior skull base is the portion between the eyes and undersurface of the brain. Both benign and malignant tumors arise in this anatomic space. Common benign tumors are pituitary adenoma, meningioma and fibro-osseous lesions. Malignant tumors are those that usually arise from the paranasal sinuses and olfactory cleft. Lateral skull base tumors are extremely rare and can also be benign (glomus jugulare) or malignant (temporal bone cancer).
2. What tests are needed?
In general, a scan (CT/MRI/PET) and a biopsy, if necessary, are needed. Additional investigations may be necessary depending on the type of tumor.
3. How are skull base tumors treated?
Whether benign or malignant, skull base tumors in general need surgical removal. The approach (endoscopic vs open) is determined by the nature, location and extent of the tumor. If feasible, endoscopic approach (Expanded Endoscopic Sinus Surgery- see Minimally Invasive Surg) is preferred, as it avoids a scar, lessens pain and leads to faster recovery. This approach is very suitable for pituitary adenomas, small-to-medium anterior skull base tumors and fibro-osseus lesions. For bigger tumors that have destroyed the cribriform plate (bone that separates the brain and nose) with significant extension into the cranial cavity, an open craniofacial approach is usually necessary. Similarly for large tumors with significant extension into the infratemporal fossa, a mandibulotomy approach may be required. For cancer of the ear, a lateral temporal bone resection may be required.