Tuberculum Sellae Meningioma

by Robert G. Ojemann, M.D.
Stephen B. Tatter, M.D., Ph.D., HTML editor

These meningiomas usually arise in the midline from the region of the tuberculum sellae and planum sphenoidale. As the tumor enlarges, it compresses the optic nerves and chiasm (fig 1). The most common initial symptom is asymmetric loss of visidn starting with unilateral decreased acuity or blurring in the visual field followed by progression to bilateral involvement. When the tumor is large there can be a frontal lobe syndrome. On examination there is usually a reduction in visual acuity and often an asymmetric bitemporal field defect

Figure 1: Tuberculum Sellae Meningioma As the tumor grows, it compresses the optic nerves and chiasm, displaces the internal carotid artery laterally and involves the anterior cerebral artertes.

Magnetic resonance imaging (MR1) outlines the tumor (Fig 2) and its relationship to the optic nerves, chiasm, and internal carotid artery and its branches. In most patients angiography is not needed.

The indication for surgical treatment is usually worsening vision Surgical removal of the tumor gives the best chance for relief of symptoms and the best possibility of cure in the majority of patients. Surgery should be considered in an asymptomatic patient because of the likely probability of future visual symptoms. When large tumors involve the optic nerves, internal carotid, or anterior cerebral arteries and there is dense adherence, it may be wise to leave a small amount of tumor. Radiayion therapy is recommended when there is evidence of recurrence on MRI after radical subtotal removal.

For most patients a right subfrontal exposure is used, elevating the frontal lobe just in front of the sphenoid wing. Careful microsurgical dissection is done after internal decompression of the tumor and interruption of the blood supply along the tuberculum. The involved dura is removed and, if needed, the optic canals are opened to remove any extension of tumor.

Figure 2: Tuberculum Sellae Meningioma This 32 year old woman had this MRI with gadolinium enhancement because of a history of non-localizing headache. Neurophthalmologic examination was normal. Operation was recommended because of the proximity of the tumor to the optic nerves and chiasm, her age, her wish to become pregnant and the low risk associated with surgical removal. Total removal using a right subfrontal approach was followed by complete recovery with normal vision.

In my series of 23 patients there were 20 females and three males ranging in age from 20-77 years with five over 70 years of age. The indication for surgery in all but three patients was worsening vision. In one it was a frontal lobe syndrome, in one an asymptomatic recurrence and in the other patient there were no symptoms (See Figure). In 20 of the 23 patients there was a good outcome. In two patients a preoperative frontal lobe syndrome did not improve and one patient had recurrence of an atypical meningioma.

After operation vision was improved in 13, the same in eight and worse in only two. Two patients had transient changes in mental function that recovered. When diabetes insipidus occurred, it was transient.

Radiation therapy was used in six patients, one with subtotal removal and two with radical subtotal removal in whom postoperative scans showed beginning regrowth of tumor and in three patients where operation had been done for recurrence. In five of these six patients there has been no evidence of further growth during a follow-up period of three to nine years. One, who had the optic nerve and chiasm encased in tumor, has shown reduction in size of the tumor and dramatic improvement in vision in one eye. In the last patient, an atypical meningioma continued to recur in spite of radiation therapy and further surgery.

REFERENCES

1. Ojemann RG. Management of cranial and spinal meningiomas. Clin Neurosurg 1993; 40:321-383.
2. Ojemann RG. Surgical management of olfactory groove, suprasellar and medial sphenoid wing meningiomas. In: Schmidek HH, ed. Meningiomas and Their Surgical Management, Philadelphia: WB Saunders Co 1991:242-259.
3. Ojemann RG. Meningiomas: Clinical features and surgical management. In: Wilkins RH, Rengachary SS, eds. Neurosurgery, New York: McGraw-Hill 1985:635-654.

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