Parasellar tumors are growths near the part of the brain known as the sella turcica. The most common surgical treatments for parasellar tumors are craniotomy and transsphenoidal surgery; the nonsurgical treatment is stereotactic radiosurgery.
The sella turcica is a depression in the skull base where the pituitary gland resides. The hypothalamus, optic chiasm, and carotid arteries are all located nearby. Parasellar tumors are a diverse group of brain tumors that share only one common trait: They arise near the sella turcica. They include, but are not limited to:
- Germ cell tumors
- Epidermoid and dermoid cysts
- Metastatic tumors
- Rathke cyst
- Chordomas and chondrosarcomas, collectively called clival tumors
Symptoms vary depending on tumor type, size, and precise location. Common symptoms include headache, nausea, vomiting, and visual loss. Tumors that block the cycling of cerebrospinal fluid may cause hydrocephalus. Also, endocrine disruption, which includes conditions like diabetes insipidus, hyperprolactinemia, and hypopituitarism, may occur. There are many possible symptoms of endocrine disruption, a few of which include fatigue, weight loss, and infertility.
A neurological examination is typically performed to identify symptoms. This exam includes evaluation of eye movements, hearing, sensation, motor function, swallowing, sense of smell, balance, and coordination.
Diagnosing parasellar tumors relies largely on imaging studies.
Computed tomography (CT) scan and magnetic resonance imaging (MRI) can be used to visualize the tumor. The imaging test of choice is MRI because of its superior ability to provide detail, but CT scans provide a good alternative for certain patients. MRI or CT scans may be performed with or without contrast enhancement.
To confirm a diagnosis, most of the time a biopsy is required. The tissue sample may be obtained either before or during surgery.
The causes of parasellar tumors are not fully understood.
Most tumors arise sporadically, but some tumors, depending on type, are familial and associated with certain rare genetic conditions. For instance:
- Individuals with neurofibromatosis type 1, Li-Fraumeni syndrome, or Turcot syndrome have an increased likelihood of developing gliomas.
Individuals with neurofibromatosis type 2 are predisposed to having acoustic neuromas and meningiomas.
- Individuals with tuberous sclerosis complex are at increased risk to develop a chordoma or glioma.
- Individuals with Ollier disease, Maffucci syndrome, or Paget disease have a greater-than-average chance of developing chondrosarcomas.
Individuals who have been exposed to radiation—such as that from X-rays, CT scans, or gamma rays used during tumor treatment—may have elevated risk of glioma or acoustic neuroma.
Parasellar tumors can occur at any age.
At Columbia, our neurosurgeons use the latest surgical techniques to treat parasellar tumors, providing the best possible outcomes.
The standard treatment under most circumstances is surgical resection. This can be done by performing either a craniotomy, in which a small piece of skull bone is temporarily removed to access the tumor, or by transsphenoidal surgery, in which the tumor is accessed by operating through the mouth or nose. Transsphenoidal surgery is often performed with the aid of an endoscope or a microscope.
Our neurosurgeons resect as much tumor as possible during surgery. But because parasellar tumors are near—and often connected to—vital structures, subtotal resection is sometimes achieved and followed with adjuvant treatment. Residual tumor may be treated effectively with stereotactic radiosurgery, in which a highly focused beam of radiation targets the tumor cells specifically and leaves the surrounding brain largely unaffected.
Some parasellar tumors are small enough that stereotactic radiosurgery alone may be sufficient to treat them, rendering open and endoscopic surgery unnecessary.