Tuberculum Sellae Meningioma
by Robert G. Ojemann, M.D.
Stephen B. Tatter, M.D., Ph.D., HTML
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.
- Ojemann RG. Management of cranial
and spinal meningiomas. Clin Neurosurg 1993; 40:321-383.
- 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.
- 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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