File 2: TUBERCULUM SELLAE MENINGIOMAS
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G. OJEMANN, M.D.
© Congress of Neurological Surgeons Honored
Originally Published Clinical Neurosurgery, Volume 40, Chapter
17, Pages 321-383, 1992
Used with permission of the Congress of Neurological Surgeons.
HTML Editor: Stephen
B. Tatter, M.D., Ph.D.
The information and reference materials contained herein are intended
solely to provide background information. They were written for an
audience of physicians. They are in no way intended to constitute
medical advise. For medical advise a physician must, of course, be
| FIG. 17.3. Tuberculum
sellae meningioma. This 36-year-old presented with decreased
vision. After operation, vision was normal. (A) CT
axial images, showing a large meningioma. (B) MRI
axial TI image after gadolinium, showing the small residual
tumor adherent to the anteiior cerebral arteries after a
radical subtotal removal. When the residual tumor started
to grow on follow-up MRI, radiation therapy was given, with
arrest of the growth.
TUBERCULUM SELLAE MENINGIOMAS
(Meningioma Management, File 3)
MRI outlines the tumor and its relationship
to the optic nerves, chiasm, and internal carotid artery and its
branches (48). In most patients angiography is not needed and there
is no indication for embolization.
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 curing the patient. Surgery should also be considered in an asymptomatic
patient because of the likely probability of future visual symptoms.
When large tumors involve the optic apparatus, internal carotid,
or anterior cerebral arteries with dense adherence, it may be wise
to leave a small amount of tumor (radical subtotal removal). Radiation
therapy is recommended when there has been a subtotal removal with
an inadequate decompression or there is evidence of recurrence on
MRI after radical subtotal removal (Fig. 17.3). 1 have tended to
wait on this recommendation for evidence of regrowth unless the
operation has been done for recurrence.
In general, I prefer a right subfrontal
exposure, elevating the frontal lobe just in front of the sphenoid
wing (Fig. 17.4A and B) (47, 54, 55). A left subfrontal exposure
is utilized when the tumor bulk is greater on that side and occasionally
a bifrontal exposure is used for large tumors. Guthrie et al. (26),
Andrews and Wilson (7), and Grisoli et al. (22) have also used the
right subfrontal approach unless the visual loss is greater on the
left side. Logue (37) and Symon (74) use a unilateral right subfrontal
exposure but approach the tumor along the midline. Al-Mefty and
Smith (5) use a unilateral supraorbital exposure. For large tumors,
Al-Mefty et al. (3) use a bifrontal craniotomy. Symon (74) resects
a portion of the frontal lobe.
| FIG. 17.4. Tuberculum
sellae meningioma. (A) Incision and bone flap for unilateral
subfrontal exposure. (B ) The tumor may surround
a portion of the right optic nerve, displace the internal
carotid artery laterally, and involve the anterior cerebral
arteries. (C) The tumor is opened along its attachment
to the tuberculum, the blood supply is interrupted, and
an internal decompression is done. The attachments to the
right optic nerve are being separated. (D) The left
optic nerve is exposed after the decompression. The tumor
is being separated from the anterior cerebral artery complex.
The key considerations in the operation
- Internal decompression of the tumor
and interruption of the blood supply along the tuberculum (Fig.
- Careful microsurgical dissection.
As the tumor grows, it elevates and displaces the optic nerves
laterally and may surround the nerves (Fig. 17.4B). The internal
carotid artery is also displaced laterally and may be engulfed
by tumor. Growth may extend posteriorly above the chiasm to involve
the anterior cerebral arteries (FIG. 17.4D) and in large tumors
compresses the hypothalamus.
- Awareness that if the tumor is large
the pituitary stalk is displaced posteriorly and the tumor may
extend into the interpeduncular cistem but there is usually an
intact arachnoid membrane.
- Removal of the involved dura.
- If needed, exposure of the optic
canals to remove an extension of tumor.
Table 17.2 records the results for
21 patients with tuberculum sella meningioma. There were 18 women
and three men ranging in age from 20 to 77 years, with five over
70 years of age. The indication for surgery in all but two patients
was worsening vision. In one of these it was a frontal lobe syndrome
and in the other an asymptomatic recurrence seen on 'CT of an atypical
meningioma previously operated on at another hospital. In 18 of
the 21 patients there was a good outcome. The fair result was in
a lady who had already had four operations for her tumor before
we saw her. Mild frontal lobe symptoms did not improve and vision
was worse. The two poor results were in a 73-year-old woman with
a severe frontal lobe syndrome that did not improve and in a 61-year-old
dentist with an atypical meningioma who had tumor growing under
his optic nerve into the optic canal. He did well for 5 years after
radical subtotal removal and radiation therapy and then the tumor
recurred with rapid growth; he did improve with further surgery.
After operation vision was improved
in 12 patients, the same in seven, and worse in only two. Two patients
had transient changes in mental function that recovered. When diabetes
insipidus occurred, it was transient.
The patients with radical subtotal
removal had a small area of tumor left adherent to the internal
carotid or anterior cerebral arteries or under the optic nerves
(Fig. 17.3B). Subtotal removal
|TABLE 17.2 Tuberculum
||2 after RST
||1 after ST
- aT, total removal
- RST, radical subtotal removal
- ST, subtotal removal
- bGood, free of
major neurological deficit
and able to return to previous activity level
- Fair, independent but not
able to return to full activity
because of new neurological deficit or significant
preoperative deficit that did not fully recover
- Poor, dependent.
was done in two patients with recurrent
tumors in whom the optic and arterial structures were encased in
tumor. One elderly patient also had a subtotal removal.
Radiation therapy was used in six
patients, one with subtotal removal, two with radical subtotal removal
in whom postoperative scans showed beginning regrowth of tumor,
and 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 2-8 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.
The series of Symon and Rosenstein
(75), Andrews and Wilson (7), and Al-Mefty and Smith (5) also reported
good results from surgery. A long history of visual impairment does
not preclude good recovery but improvement is more likely when the
history is of relatively short duration (21).
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