Olfactory groove meningioma

Introduction

The most common tumors along the anterior skull base are meningiomas. Among midline anterior skull base tumors, the most common locations in order of frequency are the olfactory groove, planum sphenoidale, and tuberculum sellae. Olfactory groove meningiomas account for 5% to 15% of intracranial meningiomas, and typically arise from arachnoid cells of the cribriform plate of the ethmoid bone or the frontoethmoidal suture. These lesions often frequently invade the bone and generate an osteoblastic resection. In this chapter, we present a case of a patient with an olfactory groove meningioma.

Example case

Chief complaint: malodorous sensations with decreased smell

History of present illness

A 50-year-old, right-handed woman with a history of hypertension presented with malodorous sensations with decreased smell. For the past several years, she has noted decreased smells with intermittent periods in which she sensed malodorous sensations. She was seen by an ear, nose, and throat doctor who recommended imaging. A brain lesion was seen, and this was followed with a follow-up imaging that showed progressive growth and edema over 6 months ( Fig. 41.1 ). She was referred for evaluation and management.

Medications : Lisinopril.
Allergies : No known drug allergies.
Past medical and surgical history : Hypertension.
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; Absence of smell to camphor and alcohol.

	Francesco DiMeco, MD, Massimiliano Del Bene, MD, Carlo Besta Neurological Institute, Milan, Italy	Ricardo J. Komotar, MD, University of Miami, Miami, FL, United States	Daniel M. Prevedello, MD, Ohio State University, Columbus, OH, United States	Hirofumi Nakatomi, MD, PhD, University of Tokyo, Tokyo, Japan
Preoperative
Additional tests requested	Head CT to evaluate bony involvement and lesion density/calcifications	Head CT to evaluate frontal sinuses	CT angiography University of Pennsylvania smell test Neuropsychological assessment	Cerebral angiogram ENT evaluation for possible biopsy DWI for sinusitis Alinamin test for smell detection Neuropsychological assessment
Surgical approach selected	Right fronto-temporal craniotomy	Right transpalpebral supraorbital craniotomy	Endoscope endonasal transcribriform	Bifrontal craniotomy
Anatomic corridor	Right subfrontal	Right subfrontal	Transcribriform	Basal interhemispheric/subfrontal
Goal of surgery	Near total resection with residual in ethmoid, Simpson grade 4	Gross total resection, Simpson grade I	Gross total resection, Simpson grade I	Near total resection, Simpson grade 2, SRS of nasal component
Perioperative
Positioning	Right supine with 30-degree left rotation	Right supine slight left rotation	Supine, right head turn and left tilt in pins	Supine neutral
Surgical equipment	Surgical navigation Chisel Surgical microscope Ultrasound Ultrasonic aspiration	Surgical navigation Surgical microscope Ultrasonic aspirator	Surgical navigation Ultrasonic aspirator Tissue cutting device Endoscopes	Lumbar drain Surgical navigation IOM (VEP, SSEP) Surgical microscope Ultrasonic aspirator Weck and AVM clips Microanastamosis set
Medications	Mannitol Steroids Antiepileptics	Mannitol Steroids	Mannitol Steroids Antiepileptics	Steroids Antiepileptics
Anatomic considerations	Orbital roof, frontal sinus, inferior frontal gyrus, orbital gyrus, gyrus rectus, ACA and branches, olfactory groove, falx, basal cisterns	ACA, optic nerves, frontal sinus	ACA/ICA, optic nerves, orbits, frontal lobes	Olfactory nerves, ACA and branches
Complications feared with approach chosen	CSF leak, rhinorrhea	CSF leak, frontal sinus violation	Brain retraction, tumor recurrence	Olfactory nerve and ACA injury
Intraoperative
Anesthesia	General	General	General	General
Skin incision	Right fronto-temporal curvilinear	Right eyebrow	None	Bicoronal
Bone opening	Right frontal	Supraorbital, lateral to frontal sinus	Bilateral middle turbinectomies/anterior and posterior ethmoidectomies, sella/tuberculum/planum/bilateral fovea ethmoidalis, crista galli and cribriform	Bifrontal
Brain exposure	Right frontal pole, temporal lobe, sylvian fissure	Right frontal pole	Anterior cranial fossa	Bilateral frontal
Method of resection	Right fronto-temporal craniotomy eccentric to the frontal side avoiding frontal sinus and paralleling orbital roof, craniotomy without burr hole, drill down lesser sphenoid wing, S-shaped dural opening with first limb paralleling orbit, as well as paralleling middle fossa floor, open basal cisterns, frontal lobe retraction with fixed brain retractor, interrupt blood supply from dural attachment, intralesional debulking, dissection of dome from pia, identification and preservation of olfactory nerves, leave ethmoidal portion alone to prevent CSF leak, skull base reconstruction with dural substitutes and autologous material if needed (pericranium, fat), watertight dural closure	Incision over right eyebrow, right supraorbital craniotomy lateral to the sinus based on navigation, dural opening, microscopic visualization and opening of opticocarotid cistern to allow brain relaxation, devascularize tumor from skull base, debulk tumor, dissect margins, remove dural and bone origin as needed, dural replacement, watertight dural closure	Bilateral middle turbinectomies/anterior and posterior ethmoidectomies, right nasal flap raised and kept in lateral aspect of sinonasal cavity, Draf III frontal sinus, removal of sella/tuberculum/planum/bilateral fovea ethmoidalis, removal of hyperostotic bone, ligation and severing of anterior and posterior ethmoidal arteries, removal of crista galli and cribriform plate, dura opened, falx cut anteriorly, tumor debulked, extracapsular dissection is performed and separated from ACAs and optic nerves, reconstruction with dural substitute/fat graft/nasoseptal flap	Lumbar drain, right thigh muscle fascial preparation, bicoronal incision with preservation of pericranium, bifrontal craniotomy with drilling of crista galli, W-shaped low dural opening, devascularize tumor at skull base along olfactory groove dura to planum sphenoidale until prechiasmatic cistern identified, debulk tumor in all four quadrants, after enough debulking then capsule dissection from frontal lobes, identify pial and dural feeders, microanastamosis if vascular injury encountered, repair dura with pericranium and thigh fascia, subgaleal drain
Complication avoidance	Navigation to stay lateral to frontal sinus, early devascularization, internal debulking, leaving ethmoidal content alone	Navigation to stay lateral to frontal sinus, internally debulk	Large bony opening, coagulation of dura and ethmoidal arteries, internal debulking before extracapsular dissection	IOM, devascularizing tumor early, debulking prior to capsule manipulation
Postoperative
Admission	Floor	ICU	ICU	ICU
Postoperative complications feared	CSF leak, rhinorrhea	CSF leak, pseudomeningocele	CSF leak, seizures	Loss of smell, CSF leak, seizures, neurocognitive decline
Follow-up testing	CT within 24 hours after surgery MRI 3 months after surgery	MRI within 24 hours after surgery	Head CT immediately after surgery MRI within 24 hours after surgery	MRI/MRA/MRV within 72 hours after surgery
Follow-up visits	3 months after surgery	14 days after surgery	7 days after surgery with ENT	1 month after surgery
Adjuvant therapies recommended for WHO grade	Grade I–observation, radiation with recurrence Grade II–radiation Grade III–radiation	Grade I–observation Grade II–radiation Grade III–radiation/chemotherapy	Grade I–observation Grade II–observation Grade III–radiation	Grade I–observation Grade II–SRS Grade III–radiation