This document outlines information about sphenoid wing meningiomas (SWM), including: - Background on SWM classification and locations of hyperostosis - Causes of hyperostosis including tumor cell activity and bone stimulation - Presentation of SWM such as headaches, visual changes, and nerve deficits - Workup involving imaging like CT/MRI and surgical planning considerations - Treatment including options for medical management or surgical resection via approaches like pterional or orbitozygomatic to remove tumor and resect bone

1. DR.MUMTAZ ALI
NEUROSURGERY RESIDENT
JPMC,KARACHI

2. outlines
 Background
 Defination
 Classification
 Causes & location of hyperstosis
 Pathophysiology
 Epidemiology
 Presentation
 D/D
 Workup
 Treatment(medical & surgical)
 Complications
 conclusion

3. Background
 In 1614, Felix Plater
 In 1864,John cleland : cribriform plate &
right frontal sinus
 In 1915,Cushing & weed : arachnoid

4. Defination
 Meningiomas :arachnoid cap cells
 SWM : bony crest formed by wings (lesser and greater) the sphenoid bone.
 sphenoid ridge(lesser wing : internal 2/3 & greater wing its external 1/3)

5. Cont…

6. Classification
 En-plaque/spheno-orbital/hyperostotic
 Globoid meningiomas:
(1) deep, inner, or clinoidal
(2) middle or alar
(3) lateral, outer, or pterional

7. Enplaque/spheno-
orbital/hyperostotic
 carpet-like dural growth
 reactive hyperostosis
 extends :
 posteriorly :cavernous sinus
 anteriorly :orbital apex

8. Causes of hyperstosis
 vascular disturbances
 Irritation of bone without actual invasion
 previous trauma
 bone production by tumor cells
 osteoblastic stimulation of normal bone
 bone growth is actually bone invasion by tumor cells.

9. Location of hyperstosis according
to frequency
 lesser wing of the sphenoid bone
 the greater wing of the sphenoid
 The roof of the orbit
 the inferior orbital fissure
 the infratemporal fossa
 the orbital rim

10. GLOBOID MENINGIOMAS
(1) deep, inner, or clinoidal
(2) middle or alar
(3) lateral, outer, or pterional

11. Pathophysiology
 Head injury
 Radiations
 Harmonal (estrogen & progestrerone)
 Genetic(loss of DNA on 22 chromose)
 Androgen receptors(EGF,PDGF)
 Viruses(Inoue-melnick virus )
 Associated(gliomas,abscess & aneurysms)

12. Epidemiology
 Race( Caucasians, Africans, African Americans, and
Asians)
 Sex(Caucasians:75%women & 25% men.Africans show
an equal gender ratio).
 Age(onset is 50 years increases thereafter)
 Mortality(5years:87% & 10 years :58%)

13. Histologic findings
 According to the World Health Organization (WHO)
in 1993, :
 Benign (grade I) 6.9%: do not invade the brain
parenchyma.
 Atypical (grade II) 34.6%: mitosis & increased
nuclear-cytoplasmic ratio.
 Malignant (grade III and IV) 72.7%: greater mitosis,
necrosis, and invasion of brain parenchyma.

14. Presentation
 Headache
 orbital pain
 visual deficit
 Ptosis
 diplopia
 Ectropion
 Conjunctivitis

15. Presentation
corneal ulceration,
scleral hemorrhages
Oculomotor deficit
Facial hypoesthesia.
Memory impairment
olfactory hallucinations
hemiparesis.

16. Differenetial diagnosis
 Fibrous dysplasia
 Osteoma
 osteoblastic metastasis
 Paget’s disease,
 hyperostosis frontalis interna
 erythroid hyperplasia
 sarcoidosis

17. Workup
Endocrine(TSH),FSH &LH)
CT scan and MRI
auscultation of the skull
plain skull films
bone scans

18. Workup
 carotid arteriography
 Tumor markers(C-PiB)
 F-FDG PET scan
 Preoperative visual testing
 Intraoperative radiodetection of somatostatin
receptors is feasible, especially in bone-invasive
meningiomas

19. Medical treatment
 Indications:
 atypical and malignant meningiomas as an adjunct to
surgery
 partially resected benign meningiomas
 recurrence of meningiomas after a surgical resection.

20. Medical treatment
 Drugs:
 Antiestrogen(tamoxifen:nolvadex)
 Antiprogestrone(gastrinone)
 Mifepristone, RU-486 (Mifeprex)
 Antineoplastic(hydo-oxyurea & interferon alpha
2B)
 Anti-PDGF(trapidil)
 Dopamine antagonist(bromocriptine)

21. Surgery
 Indications:
 size of the lesion >2.5cm
 presence of signs or symptoms
 patient’s condition
 changes in the adjacent cerebral tissue (edema) on
imaging studies
 surgeon’s experience.

22. Goal of surgery
 radical excision of the tumor
 resection of the lesion + the dural implant (1-cm
margin) + all hyperostotic bone.

23. Preparation
 intravenous general anesthesia.
 Antiepileptic drugs
 broad-spectrum antibiotics
 Glucocorticoids
 Neurophysiologic monitoring

24. Positioning
 supine decubitus position
 the head fixed in a three-pin head holder
 head is slightly extension
 rotated toward the contralateral side of the tumor
 clinoidal tumors (between 30 and 40)
 alar and pterional lesions(between 40 and 50)

25. Skin incision
 a frontotemporal(pterional) curvilinear
 starting at the root of the zygomatic arch, just 5 mm in
front of the tragus
 runs vertically upward
 Once it passes the ear, it is curved rostrally and
superiorly toward the ipsilateral frontal region.

26. Variation in skin incision
 The midportion of incision can be extended backward,
especially in cases of pterional meningiomas with large
infiltration of the pterion.
 If an orbitozygomatic (OZ) approach is required, it is
necessary to extend the incision vertically down to the
level of the ear lobe.

28. Dissection of epicranial planes
 superficial temporal artery
 a posterior branch has to be coagulated
 Dissection continues until the temporal fascia is
identified
 Avoid wide separation between the temporal fascia
and the skin to avoid injury to the frontotemporal
branch of the facial nerve

29. Cont..
 retrograde direction
 two epicranial planes are created
 skin and temporal fascia (fasciocutaneous flap)
 temporal muscle alone (muscle flap)

30. Craniotomy & tumor resection
 anatomic variety of the meningioma
 Pterional
 Alar
 Clinoidal
 En-plaque

31. Pterional
 If hyperstosis:around the bone infiltration,bone flap of
around 5cm
 If hyperstosis is absent:standard craniotomy
 Section the tumor to elevate/remove the bone flap
 Craneictomy:osseous tumor

32. Pterional craniotomy

33. Alar
 frontotemporal craniotomy
 extradural resection of the lesser wing of the sphenoid
bone.
 Bone removal is continued until complete exposure of
the superior orbital fissure
 The dura mater is then opened following a curvilinear
frontotemporal incision, reflecting the dural flap
forward

35. clinoidal
 a frontotemporal
 resection of the sphenoid ridge
 The superior orbital fissure is also completely opened
 the posterolateral wall of the orbit is also removed in
case of orbital part of tumor
 Anterior clinoidectomy:high speed drill+irrigation
 Tumor involving optic nerve:curvillenier incision

36. Cont..
wide splitting the sylvian fissure
 Retractors are placed on the frontal and temporal
lobes

37. Cont..
 dural implants :coagulated
 distal branches of the MCA
 distal to proximal direction
 initial debulking
 Arterial dissection:proximally
 The optic nerve

40. En-plaque
 it is easier to expose the entire hyperostosis
 pterional craniotomy is combined with an OZ
osteotomy,particularly when the lesion extends into
the inferior orbital fissure, infratemporal fossa, or orbit

43. Reconstruction & closure
 resect a free dural margin
 closure of the dura mater necessarily implies
application of a graft
 Local tissue:aponeurotic galea, pericranium,or
temporal fascia
 Distant tissues fascia:lata or abdominal fascia
 Synthetic & biologic materials, but with a slightly
higher risk of infection.
 Watertight closure is mandatory

44. Cont…
 reconstruction of the pterional defect:
 Autologous materials:split calvarial bone graft or ribs
 synthetic materials:methylmethacrylate and titanium

45. Complications
 Postoperative EDH:due to wide dural detachment
 Csf leak
 Seizures:if grow near epileptogenic areas
 Cosmetic problems:inadequate reconstruction
 Infection:prosthetic material,sinus opened

46. Results
 In general, the short- and midterm follow-up results
after SWM resection are excellent
 In the majority of cases,gross total resection is
accomplished with minimal morbidity.
 However, the critical point is in long-term follow-up
because of the high risk of recurrence, which is
inversely proportional to the degree of tumor resection

47. THANK YOU