Planum meningioma

Introduction

Anterior skull base meningiomas include olfactory groove, planum sphenoidale, and tuberculum sellae meningiomas. Planum sphenoidale meningiomas account for 5% to 10% of intracranial meningiomas, and typically arise from arachnoid cells between the frontosphenoidal suture and the chiasmatic sulcus. These lesions often invade the bone and generate an osteoblastic resection, as well as displace critical neurovascular structures, including the optic nerve and chiasm, as well as anterior cerebral artery vessels. In this chapter, we present a case of a patient with planum sphenoidale meningioma.

Example case

Chief complaint: headaches

History of present illness

A 57-year-old, right-handed woman with a history of diabetes, hypertension, and hypercholesterolemia presented with recurrent headaches. She has baseline headaches, but over the past 2 to 3 months complained of worsening bifrontal headaches that worsened with activity and improved with pain medication and rest. She denied any vision problems, loss of smell, nausea, or vomiting. Her primary care physician ordered brain imaging and referred her for evaluation and management ( Fig. 42.1 ).

Medications : Irbesartan, metformin, lovastatin.
Allergies : No known drug allergies.
Past medical and surgical history : Diabetes, hypertension, hypercholesterolemia; cholecystectomy, appendectomy, tonsillectomy.
Family history : No history of intracranial malignancies.
Social history : Business owner, no smoking or alcohol.
Physical examination : Awake, alert, oriented to person, place, and time; Cranial nerves II to XII intact; No drift, moves all extremities with full strength.

	Henry Brem, MD, Johns Hopkins University, Baltimore, MD, United States	Basant K. Misra, MBBS, MS, Hinduja National Hospital, V.S. Marg, Mahim, Mumbia, India	Rodrigo Ramos-Zúñiga, MD, PhD, University of Guadalajara, Guadalajara, Jalisco, Mexico	Theodore H. Schwartz, MD, Cornell University, New York, NY, United States
Preoperative
Additional tests requested	MR angiography	Head CT Neuropsychological assessment Neuroophthalmology (visual fields) Pituitary hormone evaluation	MR angiography Neuroophthalmology (visual fields) Endocrinology evaluation	Head CT Smell test with ENT Neuroophthalmology evaluation with visual fields
Surgical approach selected	Bifrontal bicoronal craniotomy	Right frontotemporal craniotomy	Right supraorbital	Right supraorbital
Anatomic corridor	Left subfrontal	Right lateral subfrontal	Right supraorbital	Right supraorbital
Goal of surgery	Simpson grade I	Simpson grade I	Simpson grade I	Simpson grade I
Perioperative
Positioning	Supine neutral	Spine with 30-degree left rotation	Supine neutral	Right supine with 30-degree left rotation
Surgical equipment	Surgical navigation IOM (MEP/SSEP/EEG) Surgical microscope Ultrasonic aspirator	Surgical microscope Ultrasonic aspirator	Surgical microscope Ultrasonic aspirator	Surgical microscope Endoscope
Medications	Mannitol Steroids Antiepileptics	Steroids Antiepileptics	Steroids	Mannitol Steroids Antiepileptics
Anatomic considerations	Frontal sinus, olfactory nerves, ACA, ICA, optic nerves and chiasm, infundibulum, anterior clinoid	Olfactory nerves, ACA, optic nerves	Frontal sinus, frontal lobe, olfactory nerves, ACOM/A1/A2 and perforators	Frontal sinus, supraorbital nerve, olfactory nerves, ACOM, optic chiasm, A2
Complications feared with approach chosen	Frontal sinusitis, anosmia, visual field deficit, stroke, CSF leak	Bilateral frontal lone injury, venous injury, anosmia	Anosmia, vision loss	Anosmia, CSF leak, vision loss, stroke
Intraoperative
Anesthesia	General	General	General	General
Skin incision	Bicoronal	Right pterional	Eyebrow, ciliary edge	Eyebrow
Bone opening	Bifrontal craniotomy above frontal sinus	Right frontotemporal	Right supraorbital	Right supraorbital
Brain exposure	Left frontal lobe	Right frontal-temporal lobes	Right frontal lobe	Right frontal lobe
Method of resection	Bicoronal craniotomy above frontal sinus, dural opening on left, left subfrontal approach. Internal debulking of tumor on left then bilaterally, dissect capsule free from olfactory and optic nerves with preservation of ACA branches, decompress optic nerves and ICA, watertight dural closure, bone flap rinsed in Betadine	Frontotemporal incision, frontotemporal scalp flap, frontotemporal craniotomy with 3-cm subfrontal extension, semicircular dural opening based anteriorly, release CSF from Sylvian fissure, coagulation of tumor dural attachment, piecemeal excision, dissection of tumor from surrounding brain, watertight dural closure, reinforce suture line with galea and fibrin glue, placement of a subgaleal drain	Ciliary incision, supraorbital craniotomy lateral to frontal sinus, dural opening, drain cisterns under microscopic visualization, intratumoral decompression and biopsy, microvascular disconnection, capsular resection, resection and coagulation of cranial base, watertight dural closure	Ciliary incision from beyond superior temporal line to lateral edge of supraorbital notch, expose keyhole and zygoma, dissect periorbita, one piece craniotomy with removal of orbital rim, drill down skull base, open dura, open cisterns with microscopic visualization, minimize retractor use, devascularize tumor from skull base, decompress tumor, dissect from olfactory nerves/frontal lobe/optic chiasm/A2, endoscope and removal of any residual along cribriform, cement for bony defects
Complication avoidance	Craniotomy above frontal sinus, unilateral approach	Relax CSF from Sylvian fissure, coagulate tumor dural attachment	Tumor debulking, capsular disconnection	CT to evaluate sinuses, removal of orbital rim, limit use of retractor, decompress CSF early, debulk tumor before dissecting from critical structures
Postoperative
Admission	ICU	ICU	Floor	Intermediate care
Postoperative complications feared	Anosmia, visual field deficit, motor weakness	Seizures, anosmia, venous infarct, contusion, CSF leak	Visual decline, olfactory deterioration, psychomotor agitation, CSF leak	CSF leak, anosmia, stroke
Follow-up testing	MRI within 24 hours after surgery	CT with contrast within 24 hours after surgery Hormonal assay Visual field evaluation MRI 3 months after surgery	CT immediately after surgery MRI within 48 hours after surgery	MRI within 48 hours after surgery
Follow-up visits	14 days after surgery 3 months, every 6 months after surgery	8 days after surgery	1 month after surgery	5 days after surgery 3 months after surgery with MRI
Adjuvant therapies recommended for WHO grade	Grade I–observation Grade II–observation and re-resect and radiate if recurs Grade III–radiation	Grade I–observation, repeat resection for recurrence Grade II–radiation if residual Grade III–radiation	Grade I–observation Grade II–observation Grade III–radiation	Grade I–observation Grade II–radiation if not Simpson grade I resection Grade III–radiation