2. • A meningioma is, in many ways, the soul of neurosurgery
“ The progress in meningioma treatment mirrors advances in neurosurgery, and
advancements in neurosurgery are put to maximal use to improve the treatment of
meningiomas ”
3. • Meningioma is the most common benign skull base tumor
• 40% to 50% of meningiomas involve the skull base
• Constitute 32% of brain tumors
Morita A, Piergras DG. Tumors of the skull base. In: Vecht CJ, ed. Handbook of Clinical Neurology, 68
Revised Series 24 Neuro-OncologyPart II. Amsterdam: Elsevier;
4. • Incidence of meningiomas is 7.6 per 100,000 per year
• Incidence of skull base meningiomas is approximately 3.5 per 100,000 per year
Ostrom QT, Gittleman H, Liao P, et al. CBTRUS statistical report:primary brain and central nervous
system tumors diagnosed in the United States in 2007-2011. Neuro Oncol. 2014;16(suppl 4):iv1–iv63.
5. • The female-to-male ratio is about 2:1
• Equal incidence of the tumor between girls and boys
• Male predominance (71%) has been reported among infants
Sutherland GR, Florell R, Louw D, et al. Epidemiology of primaryintracranial neoplasms in Manitoba,
Canada. Can J Neurol Sci.
6. Pathology
• Originate from arachnoidal cap cells, cells forming the outer lining of the
arachnoidal membrane.
• Arachnoid villi protrude into the venous sinuses
• Venous endothelium is in contact with all or a portion of the arachnoid villi
• These cells are referred to as arachnoid cap cells.
7.
8. • Globular, encapsulated tumor
• Attached to the dura and compress the underlying brain without invading it.
• Even though invasion of the dura and dural sinuses is common, meningiomas are
usually easily separated from the pia mater
10. En plaque meningioma
• Occur as a flattened sheath of tumor, taking the shape of the underlying bone.
• More common in the area of the sphenoid bone
• Hyperostosis is a characteristic finding in en plaque meningioma
11. WHO recognizes three grades based on pathologic criteria , the risk of recurrence
and aggressive growth
12. Genetic aspect
• Genetic alterations in the long arm of chromosome 22
• Monosomy of chromosome 22 has been observed in up to 50% of patients with
meningiomas
13. • “A total of 40 specimens from primary tumors and multiple recurrences in the
nine patients were analyzed. … Loss of heterozygosity (LOH) at 22q was observed
in all meningioma cases at the earliest time point. … While allelic loss at 22q
appears to be an early event in aggressive meningioma disease ”
• Lamszus K, Kluwe L, Matschke J, et al. Allelic losses at 1p, 9q,10q, 14q, and 22q in the progression
of aggressive meningiomas and undifferentiated meningeal sarcomas. Cancer Genet Cytogenet.
14. Etiology
• Trauma
• A meningioma that contained a metal wire that had been driven into the patient’s
skull 20 years earlier by a boiler explosion.
• Preston-Martin and associates found that patients with meningiomas had a
significantly increased recall of prior head trauma relative to a corresponding
control group
Reinhardt G. Trauma-fremdkörper-hirngeschwulst. Munch Med Wochenschr
Preston-Martin S, Pogoda JM, Schlehofer B, et al. An international case-control study of adult glioma
and meningioma: the role of head trauma. Int J Epidemiol
15. “ It is suggested that trauma with resultant meningeal injury with implantation of
foreign bodies or granulomatous reactions is a contributing cause of meningioma in
a small group of patients ”
Barnett GH, Chou SM, Bay JW. Post-traumatic intracranial meningioma:a case report and review of
the literature. Neurosurgery.
16. Virus :
• One strong contender is the Inoue-Melnick virus (IMV), a DNA virus
In work reported by Inoue, IMV was isolated from six of seven human meningioma-
derived cell cultures but was not isolated from six other brain tumor cell cultures
Inoue YK. Inoue-Melnick virus and associated diseases in man: recent advances. Prog Med Virol
18. • The method, referred to as the Kienböck-Adamson technique, delivers 450 to
850 rad to the scalp and 70 to 175 rad to the surface of the brain for the
treatment of tinea capitis
“ A statistical analysis of 11,000 children and found that meningiomas were 4 times
more common in irradiated patients than in the control group”
Modan B, Baidatz D, Mart H, et al. Radiation-induced head and neck tumours. Lancet
19. Associations
• Schoenberg and associates were the first to suggest that the concomitant
occurrence of breast cancer and meningioma was higher than could be expected
from pure coincidence
• Sawaya and Rämö demonstrated a higher rate of venous thrombosis of the legs in
patients with meningiomas than in those with glioblastomas or brain metastasis
Schoenberg BS, Christine BW, Whisnant JP. Nervous system neoplasms and primary malignancies of
other sites: the unique association between meningiomas and breast cancer. Neurology
Sawaya R, Rämö OJ. Systemic and thromboembolic effects of meningiomas. In: Al-Mefty O, ed.
Meningiomas. New York: Raven
20. Distribution
• Intracranial meningiomas :
• Convexity (35%), parasagittal (20%), sphenoid ridge (20%), intraventricular (5%),
tuberculum sellae (3%), infratentorial (13%), and others (4%)
• Cushing and Eisenhardt6 subclassified convexity meningiomas as precoronal,
coronal, postcoronal, paracentral, parietal, occipital, and temporal.
21. Therapeutic plan
Surgical excision is the treatment of choice and only definitive cure
Radiation therapy is considered :
1. After surgery for a malignant meningioma
2. Following incomplete resection of a meningioma
3. For patient with multiple recurrent tumors for whom the surgeon judges
repeat surgery to be too risky
4. As a sole therapy of a progressively symptomatic patient judge by the
surgeon to be inoperable
22. • Simpson introduced a five-grade classification of the surgical removal of
meningiomas
23. • Recurrence rate for grade I is 9%; the rate for grade II is twice as high
• The inclusion of an additional 2-cm dural margin has been denoted grade 0
removal
“ In one study no recurrences were seen in patients with convexity meningiomas in
whom grade 0 resection was achieved ”
• Kinjo T, Al-Mefty O, Kanaan I. Grade zero removal of supratentorial convexity meningiomas
25. • In 1992 Kobayashi and associates revised the Simpson grading system from a
microsurgical perspectively by introducing a classification system based on the
extent of microscopic resection
29. Recurrence rate
• 5-year recurrence rate for a totally removed(grade I) meningioma is 5%
• 40% for totally removed atypical (grade II) meningiomas
• 50% to 80% for malignant (grade III) meningiomas
Riemenschneider MJ, Perry A, Reifenberger G. Histological classification and molecular genetics of
meningiomas. Lancet Neurol. 2006;
Sade B, Chahlavi A, Krishnaney A, et al. World health organization grades II and III meningiomas are
rare in the cranial base and spine.Neurosurg Online.
30. • The highest recurrence rates (>20%) - sphenoid wing meningiomas
• Parasagittal meningiomas (8%–24%)
• Convexity and suprasellar meningiomas - 5% to 10%
31. • 54 patients with supratentorial convexity meningiomas were examined at least 3
years after surgery or until tumor recurrence
• All patients had undergone Simpson grade I resection
Yamasaki F, Yoshioka H, Hama S, et al. Recurrence of meningiomas
32. • The correlation between recurrence and the following factors was statistically
analyzed: Age, sex, tumor volume, tumor shape, bone changes, brain edema,
vascular supply, histologic subtype and vascular endothelial growth factor (VEGF)
“ High levels of expression of VEGF constituted the most useful predictor of
recurrence ”
Yamasaki F, Yoshioka H, Hama S, et al. Recurrence of meningiomas
33. • Nakasu and coworkers studied 101 patients who underwent macroscopically
complete removal of meningiomas
• Patients were monitored postoperatively for at least 5 years(maximal duration, 18
years) or until tumor recurrence
Nakasu S, Nakasu Y, Nakajima M, et al. Preoperative identification of meningiomas that are highly
likely to recur. J Neurosurg.
34. • Fifteen meningiomas recurred during the follow-up period. Multivariate analysis
revealed that only the shape of the tumor was significant;“mushrooming” and
lobulated meningiomas were more likely to recur than round ones
• The extent of surgical removal has been and remains the most influential factor
in recurrence
DeMonte F, McDermott MW, Al-Mefty O. 1 Meningiomas: A Personal Perspective. Al-Mefty’s
Meningiomas F. M. DeMonte,Michael W.; Al-Mefty,Ossama. Stuttgart, Georg Thieme Verlag
Mirimanoff RO, Dosoretz DE, Linggood RM, et al. Meningioma:analysis of recurrence and progression
following neurosurgical resection.J Neurosurg.
35. Medical Therapy
“ Have been tried over the decades with only limited effect on the natural history of
meningiomas ”
• Hormone receptor based therapy :
Retrospective data suggesting somatostatin analogues like octeotride have some
stabilizing properties
BUT Prospective trials fails to confirm its significant effects
36. • Immunotherapy :
• The combination of nivolumab and pembrolizumab : showed some efficacy in
stabilizing the tumor in a subset of patient in a multicentre study
• A retrospective study ,VEGF therapies Bevacizumab showed stabilizing effects in
refractory meningioma
Lou E, Sumrall AL, Turner S, et al. Bevacizumab therapy for adults with recurrent/progressive
meningioma: a retrospective series. JNeuro Onco
Nayak L, Iwamoto FM, Rudnick JD, et al. Atypical and anaplastic meningiomas treated with
bevacizumab. J Neuro Oncol
37. Combined strategies
• Immuno plus Radiation Therapy
• Ongoing trial (NCT 02648997)
• Nivolumab versus Nivolumab plus External beam radiation therapy
38. • No significant efficacy has been achieved so far, and much detailed and arduous
work remains.
39. Asymptomatic Meningioma
• Treatment of asymptomatic incidentally discovered meningiomas is individualized
based on :
1. Tumor location,
2. Size,
3. MRI appearance (e.g., edema),
4. Patient’s age
5. Patient’s preference
40. Operative considerations
• “ Some die from meningiomas, others with them ”
• Surgeon must then weigh the risks and benefits of surgery against the natural
history of the disease
41. • Total removal based on circumstances encountered during surgery
• Invasion of neurovascular structures by the tumor or tight pial adhesions in vital
areas such as the brainstemor hypothalamus.
42. • Intraoperative finding of an en plaque meningioma.
• This carpet-like encasement of the skull base makes the value of surgical
resection questionable if the tumor encases vital neurovascular structures.
• En plaque meningiomas are found in the region of the sphenoid ridge, anterior
clinoid, and cavernous sinus areas.
• Lee CC, Wu HM, Chung WY, et al. Microsurgery for vestibular schwannoma after Gamma Knife
surgery: challenges and treatment strategies: clinical article. J Neurosurg. 2014;121(suppl 2):150–
159.
43. • Surgery in patients in whom radiotherapy or radiosurgery has failed
• More challenging because of diffuse scarring of the arachnoidal planes and diffuse
inflammatory changes
44. Surgical considerations
• Routine CT and MRI data sets for surgical navigation
• Bone CT - when extensive bone removal is needed
• CT angiography, MR angiography, or both when the tumor is closely related to
major arterial vessels or abuts or involves major dural sinuses
45. Addressing the vascular pedicle of the tumor early in the operation
This concept is more theoretical than practical
Because the vascular pedicle is often located at the base of the skull and at the
base of the tumor
A caveat to this biologic feature is when endoscopic transsphenoidal approaches to
skull base meningiomas are used and the base of the tumor and its vascular supply
are the first structures encountered.
46. • Meningiomas are extra-arachnoidal tumors
• Possible to remove the tumor without entering the subarachnoid space to any
significant extent
47. • Meticulous intra tumoral debulking alternated with separation of the tumor-
arachnoid interface
• Separation is accomplished either by peeling the tumor off the arachnoid or by
peeling the arachnoid off the tumor
48. Coagulation & precautions
Interface (tumor-arachnoid) coagulation : should be used Sparingly
coagulation tends to obliterate the tumor-arachnoid interface make separation
problematic
• Plus overzealous coagulation of small vessels before they are fully dissected
maybe detrimental by interrupting the vascular supply to the brain parenchyma.
49. • Control of intra tumoral oozing with topical agents such as Flosealor, Surgicel
• Intra tumoral use of hydrogen peroxide (H2O2) and its use inside the oltrasonic
aspirator
50. Extended endoscopic endonasal approaches
(EEEAs)
• Proposed for Skull base meningiomas
• Anterior skull base locations : olfactory groove and tuberculum sellae
meningiomas.
51. Even in expert hands operating in specialized centers :
• a lower resection rate,
• a higher recurrence rate
• a higher rate of cerebrospinal fluid (CSF) leak
53. Right anterior clinoidal meningioma in a 56-yearold woman evaluated because of
decreased vision in the right eye for the past couple of years.
• Preoperative scans showing involvement of the right internal carotid artery
bifurcation and the right optic nerve
54. • Navigation screen shots: during tumor removal and at the end of tumor removal
55. Microscope’s focal point is at the basilar artery bifurcation, as demonstrated by the
intraoperative photograph.
Postoperative scan showing total tumor removal.
56. Preoperative scans showing cord compression and encasement of the vertebral
artery by this en plaque type of meningioma.
57. Preoperative MR angiogram showing narrowing and encasement of the right
vertebral artery. The patient underwent balloon test occlusion of the right vertebral
artery.
Intraoperative photograph showing the vertebral artery dissected from the tumor.
64. Intraoperative pictures showing the tumor being removed
Resection cavity after tumor removal
Lower cranial nerves well demonstrated after resection
65. The tumor was completely resected through a retrosigmoid approach
Postoperative scans showing complete resection of the meningioma
66. A hypoglossal meningioma seen in a 54-year-old woman presenting with recurrent
headaches, gait difficulties and dysphagia.
• Preoperative MR images showing the extra-axial tumor with brainstem
compression
