File 2: Olfactory Groove Meningiomas
To the MGH/Harvard
Meningioma Treatment Homepage
To the Introduction and Contents of Management
of Cranial and Spinal Meningiomas
G. OJEMANN, M.D.
© Congress of Neurological Surgeons
Honored Guest Presentation
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.
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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. 17.1. Olfactory
groove meningioma. This 59-year-old man presented with
a history of a subtle change in personality, less spontaneous
activity, and mild difficulty with memory. Full recovery
followed removal of the tumor. (A) MRI sagittal Tl
image after gadolinium, showing the size of the tumor and
the relationship to the optic nerve and ethmoid sinus. In
this patient there is an unusual superior projection of
the ethmoid sinus but no tumor has invaded the sinus. (B)
MRI axial T2 image, showing the edema in the adjacent
brain areas and the anterior cerebral artery slightly separated
from the posterior capsule of the tumor. Angiography was
OLFACTORY GROOVE MENINGIOMAS
(Meningioma Management, File 2)
MRI clearly defines the extent of
the tumor, the edema in the surrounding brain, the relationship
of the optic nerves and anterior cerebral arteries, and any extension
into the ethmoid sinus (Fig. 17.1) (49). Angiography is rarely needed.
In my experience, there has been no indication for preoperative
The indications for surgical treatment
have been the presence of neurological symptoms, which may include
a change in mental function, headache, disturbance in vision, or
a seizure disorder, an asymptomatic patient with edema in the adjacent
brain areas, or MRI findings that the meningioma is near the optic
nerves (49). Radiation therapy is not recommended as a primary treatment
and would be used only to treat recurrence following radical subtotal
Rarely does the patient report loss
of sense of smell as a symptom, although it is usually documented
on examination. However, if olfaction is still present the patient
should be warned about the loss of this function, since acute loss
may be quite bothersome.
For patients with large tumors, I
prefer a bifrontal craniotomy
| FIG. 17.2. Olfactory
groove meningioma. (A) Incision and bone flap
used for bifrontal cra.rdotomy. (B) The mucosa of
the frontal sinus has been removed, and the sinus is packed
with bacitracin-soaked getfoam and covered with a flap of
peiicranial tissue sewn to the dura. (C) The anterior
sagittal sinus is ligated. (D) The blood supply coming
in through the midline base of the skull is being occluded
and an internal decompression of the tumor done. (E)
The capsule of the tumor is being reflected into the
area of internal tumor decompression and the attachments
to the surrounding brain divided. Minimal retraction is
placed on the surrounding brain. The major trunk of the
anterior cerebral artery is dissected off the tumor (arrow)
but a branch going into the capsule is coagulated and divided.
(F) The posterior inferior capsule is dissected off
the arachnoid over the region of the optic nerve and internal
carotid artery (arrows). (G) The dural attachment
has been excised. The bone usually does not need to be removed.
The area is covered with a graft of perieranial tissue and
(Fig. 17.2A-C) (47-49). This approach
is associated with the smallest amount of retraction on the frontal
lobes, gives direct access to all sides of the tumor, and allows
one to decompress the tumor while working along the base of the
skull to interrupt the blood supply. Guthrie et al. (26) and Long
(38) also prefer the bifrontal exposure. For smaller tumors, a right
subfrontal approach coming laterally over the orbital roof may be
used (49). Hassler and Zentner (29) use a pterional approach. Logue
(37) and Symon (74) use either exposure and may resect part of the
frontal lobe, as do Solero et al. (69).
The key considerations in the operation
Dividing the attachments along the
skull base to interrupt the blood supply (Fig. 17.2D).
Doing an extensive internal decompression
of the tumor (Fig. 17.2D).
Retracting the tumor capsule into the
area of decompression to keep traction on the frontal lobes to a
minimum (Fig. 17.2E).
Carefully separating the tumor from
attachments to the optic nerves and anterior cerebral arteries.
The major branches of the anterior cerebral arteries are usually
separated from the tumor by a rim of cerebral tissue or arachnoid
but in large ineningiomas these arteries can be involved with the
tumor capsule. Frontopolar and small branches of the anterior cerebral
arteries may be adherent to the posterior or superior tumor capsule
and can be taken with the tumor (Fig. 17.2F).
Excising the dural attachment and when
present the hyperostotic bone, with care taken to avoid entering
the ethmoid sinus unless it is known that tumor extends into that
area (Fig. 17.2G). Symon (74) reported that the recurrence rate
of these tumors is so low that there is no need to extensively treat
the bone and I agree.
Covering the region of the dural attachment
with a graft of pericranial tissue and gelfoam.
There were 19 patients with olfactory
groove meningiorna (Table 17.1). This group included 14 women and
five men ranging in age from 23 to 73 years, with three over 70
years of age. Complete removal was done in 18 and one had a radical
subtotal removal with a small fragment left on the internal carotid
artery. In IS patients there was a good result. There was one postoperative
death due to pulmonary embolus. In other reported series the operative
mortality has also been low (29, 74).
The incidence of complications was
low and did not interfere with eventual recovery. In this series
one patient had a cerebrospinal fluid leak through the ethmoid sinus
that required transethmoidal repair, one patient developed a wound
infection that cleared, and one 71-year-old woman required treatment
of a subdural hygroma with a subdural-peritoneal shunt. Disturbance
in mental function and personality changes present preoperatively
|TABLE 17.1 Olfactory
||Cerebrospinal fluid leak
- 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.
in the postoperative period usually
recover completely. Preoperative visual symptoms usually recover
and headache is relieved.
The recurrence rate has been very
low. In this series there has been no evidence of recurrence and
this has been confirmed by scans in 13 of the 19 patients over 1-12
years (mean, 4.4 years). Chan and Thompson (11) reported no recurrence
during an average 9-year follow-up.
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