180
Intracranial schwannoma of the facial nerve: Report of two cases and r eview ofthe literature G. Roccht.M. A rtico . P. l.unardi. F M. Gagliardi Departmen t of'Neurologtcal Seiences. Section of'Neuros urgery. University ofRome "La Sa pienza ". Rome. ltal y
Two cases of intr acra nial facial schwannoma growing from the labyrinthine portion of the facial nerve are report ed. The clinlcal. patho logical and diagnostic feat ures and treatme nt of these ra re lesions are discussed in the light of the most important literature on this topic.
Ein intrakranie lles Schwan nom d es Faz ialis - Bericht übe r 2 Fälle und Literatu rübersicht Zwei Fälle eines intra kra niellen Faz ialisSchwannoms werd en beschrieben, welches sich im Labyrinthgebiet des N. facialis entwickelte. Die klinische n, pathologischen und diagnostischen Besond erh eite n und die Beha ndlung diese r seltene n Fälle werden anha nd der bisher verö ffentlichten Liter atur besprochen. Key-Wor ds Facia l nerve - Schwa nnoma - Geniculate ganglion - Facial paresis
Introd uctio n Schwarmomas of the facial nerve are uncommon tum ours, accounting for about 0.8 % ofall intr apetrosal space -occupying lesion s (20, 22, 24 , 26). More tha n 160 cases hav e been reported , mainly by otologists (12,1 7, 18, 20 ,21 , 24 , 26, 271. Most of these tumo urs arise from the distal porti on of the nerve within the facial cana l, a few from the geniculate gan glion and hori zontal portion of the facial ca nal (2, 9, 12 , 15, 29). Very ra rely do these lesions have an intracranial development (1- 3, 6-9, 11- 13 , 15- 23, 25 , 27). 'Ne report two cases of facial nerve schwannoma with growth into the middle cra nial fossa and an alyze the clinical and ra diological featur es and tr eatment of these lesions by reviewing th e relevant pub lished work.
Neurochirurgta 34 (199 1) 180 -18 3 © Georg Thieme Verlag Stuttgart -Xew York
Case 1. A 16 yearol d male cam e to observation for a 5-month history of progressive peripheral pa resis of the right facial nerve and some loss of hearing in the right ear one month before admission. Neurological examination revealed severe pare sis of cra nial nerve VIIon the right side together with a perce ptive heari ng loss on the sa me side. Plain X-ray films of the skull showed a patch of erosion on the medial aspect ofthe dorsum oft he right petrous bone at tegmen tympa ni level. A CT br ain scan imaged a mass on the upper port ion oft he petrous bone and extending into the middle cra nial fossa (Fig. 1). After intravenous injection of contrast medium the lesion en ha nced appreciably. Angiogra phy of the cerebra l circulation revealed a slight upwa rd displacement of the distal bran ches of the sylvian complex on the sa me side. A right temporal cra niotomy followed by extradural exposur e disclosed a roundish walnut-sized lesion originati ng from the labyrinthin e portion oft he facial nerve sheat h. The tumou r. with the ap pea rance ofa schwa nnoma, protru ded into the middle cra nial fossa thr ough a c1earcut patch of bone ra refaction extending to the entire tegmen tympan i. Tumour removal was total and the facial nerve, though thinned and compressed by the lesion , was preserved. On histological examinatio n the tumour proved to be a typical schwannoma. The postoperative course was uneventful an d on discharge the facial par esis was uncha nged. At follow-up 8 months later the patient still had a slight facia l pa resis an d a CT sca n showe d no recur rence. Case 2. This 23 yea rol d malec onsulted us in June 1988 for a severe dista l pa resis of the left facial nerve of 3 year sta nding. One year before admission he bega n to complain hypoacusia on the sa me side. The clinical findings on admission were : complete paresis of the left facial nerve comb ined with a homolateral perceptive hearing loss. Plain X-ray films of the skull wer e unrema rka ble. Tomogra phy of the 1eftpctrous bone sho wed a patch of bone ra refaction on its upper wall. A CT brain scan revealed a mass on the floor of the middle cra nial Iossa aga inst the petrous bone, which was ero ded. The lesion enha nced on intr avenous injectlon of contras t an d a small fingerlike process could be see n protrud ing into the internal auditory ca nal (Fig. 2). Angiography with the subtractio n technique revealed a pathological circ ulation in the middle cra nial fossa during the capillary pha se IFig. 3A). The tympanie artery in the oblique view (Fig. 3B) was disp1aced upwards arc hwise .
Left temporal cra niotomy followed by extradural exposure revealed a tumour that seeme d to a rise from the petrous bone at tegmen tympan i level. The 1esion, the size ofa walnut, was growlng within the petrous bone to reac h the intern al a uditory ca nal. Although it was hard to distinguish from the facial ne rve, the tumour was re moved completely. The histological diagnosis was schwa nnoma. Because of the prot racted den ervation tha t had taken place before surgery. a facial-hypoglossal anasto mosis operation was not per formed.
Downloaded by: NYU. Copyrighted material.
Case Repor ts Su mmary
/I;'ell rochi ru rgi a 34 (1991)
Intracranial scluoannoma oj the[acia ! nerce
181
-
Fig. 1 Gase 1.Cl sean after mtravenousinlection of eontrast medium showing a mass loeated in the middle cranial tossa at the tegmentympani level
Downloaded by: NYU. Copyrighted material.
Fig. 3a
Fig. 2a
Fig.2b Fig. 2 Gase 2. Cl atterIntravencusiniection of eontrast mediumshowing in theaxial (A)scan anextradural (arrows)tumour onginatingfromthe labyrinthine po-nonof thepetrousboneandextendinginthemiddlecranialfossa and into the internal auditoryeanal (Iittlearrows).Note theremarkable erosion of thepetrous bone more evident in the eoronal (B)Cl scan
Fig. 3 b Fig.3 Gase 2.Selectiveangiography ot theexterne! earotidartery,acccmplished with thesubtraetiontechnique. showingapathclogicatcirculation(A)in themodleetamal fossa in thelateralview. Thetympanicartery is displaeed upwards archwise (arrows) in the oblique vew (B)
Discussion
S aito and Baxte r (24) consider tha t cranial nerve VII schwanno mas originate from the nervus intermedius at the point of connection with the geniculate ganglion and from aberrant ganglionic cells in the verticaJ portion of the nerve. More recently Rosenblum et al. (23) con-
firmed this interpretation. pomtmg out that tumou rs developing from the geniculate ganglion can easily grow towards the base ofthe skull through a zone ofleast resistance, na mely the thin bony lam ina overlying the ganglion, and so occupy an extrad ural intr acrani al site in the middle cra nial fossa.
Neurochirurgia 34 (1991J
G. Rocctü. M . Artico. P. Lunardi, F.M. Gaqliardi
Isamat et al. (8) argu ed thatlesions arising from the labyrinth ine portion of the facial nerve and from the geniculat e ganglion are stri ctly within the purview of neurosurgery and present a uniform clinical and radiologtcal patt ern. Cran ial nerve VII schwannomas with intra cra nial development are rarely encountered in neurosurgical practice, there being only 25 reported cases (Table I ) plus our own two. These tumours show no parti cular sex prefer ence: of the 27 cases covered by this review 15 were in fernales and 12 in males. The age rang e is from 4to 67 years with a mean age of 32 and a certain predileclion for the first two deca des oflife (8 cases out of2 7 or 29.6 %).
Table t
In 15 cases (2,3, 7- 9,12-15, 17,22-24,27 , 28) the lesion developed exd usively in the midd le cranial fossa, while in 6 cases it was confined to the cere bellopontine angle (6, 11, 19, 21), behaving clinically and radiologically like others spa ce-occupying lesions at that site. In the remain ing 4 cases the tumour present ed an hourglass development straddling the middle cranial and posterior cra nial fossa (I , 17, 18). In our two cases the tumour , though growing mainly in the middle cra nial fossa , present ed a small digitation into the internal auditory canal, but the lesion remain ed strictly extradural. The clinical history ran ged from 2 month s to 26 years with a mean duralion of 6.7 years. Clinical onset was ma rked in 15 cases (62.5%) by a peripheral paresis of cranial nerve VII on the lesion side. Other early signs were
27 Gases ot intracranial facial nerveschwannomas
Author
I Duration
I Surgical approachandtindings
I Dealness Facial peresis Feetal weakness
I Byrs
12yrs Byrs
I Extradural MCFapproach, petrous bone eroscn Extradural MCFapproach, eggsizedtumor Intradural MCF approach, tumor weight ,. 25 gm, petrous bone erosron Intradural temporal approach, cystic tumor Mastoidectomy, extradural MCF approach, tegmen tympani eroslcn. large tumor Mastoidectomy, extradural MCFapproach, petrousbone erosion Fronto-temporo-parietal craniotomy, lemon sized tumor Translabyrinthineapproach, CPA tumor 2.5 x 2.5 cm originatingft om thegeniculate ganglionandprotruding throughthe petrous bone Extradural MCF ecoroacn oetrous bone eroslon Extradural MCF eooroacn 1.0x 1.5cm Subtemporal craniotomy, 4 x 4 cm tumor Extradural MCFapproach, petrousbone8 x 10mm defect Subcccipitalapproach, audüorycanalunrootec.small
Clinical onset
l o,e,1950 Kleinsasser et al., 1959 Furlow, 1960
Curtin et al., 1964
20 F
Facial weakness Facial paralvsrs
Hora & Brown, 1964
37 F
Hearing loss and paracusias
2 yrs
Stewart. 1966 Pulec, 1972
38 M 55 F
Recurrent facial paresis Hearing 10 55 end paracusias
26y rs 2 yrs
Lihequist et al., 1972 lsamat et al, 1975
67 4 42 41
Facialpalsy and deafness Facial paresis Hearingloss Hemifacial spasm
7mo 3yrs 19 yrs
42 M
Deatness
15 yrs
Liliequist, 1978 Gonzalez-Pardo et al., 1980 Beaumont, 1981
19 M 16 F 14 M
Nedzelskiet al., 1982 Latack et al., 1983
31 F 58 F
Nakao et al., 1984
69 F 66 M 44 M
Facial paresrs 12 yrs Dizzinessandtacial palsy 2 mo Facial weaknessand hemifacial 3 yrs spasm Hearing loss andparacusias 5 yrs Hearing loss and hemifacial 2 yrs spasm Hearing loss 6 yrs Hearing loss 6mo Hearingloss, hemifacialspasm. 4 yrs tacial paresis Hearing difficultyand facial 17 yrs paresrs Faclal paresis 13yrs
44
M
5 yrs 15 yrs
F F F M
2.5 mo
tumcr
51 F Murata et al., 1985
39 F 30 F
Rosenblum et al., 1987
26 F
Ourcase 1
16 M
Our case 2
23 M
Paracusias. hearingloss,facial paresrs Progressivetaotat paresis. heanng lcss Progressivetacial paresisand deafness Facial paresis and deafness
10 mo
5mo 5mo 3 yrs
Temporal craniotomy, buge extradural tumor Suboccipitalcraniectomy,3 x 5 x 7 cmtumorin theCPA Suboccipitalcraniectomyand extradural MCF approach; small extradural tumor Suboccipital cramectorny. 3.5 x 3.5cm tumor intheCPA Suboccipttal craniectomy, 1; 2 x 1cmtumcr lntheCPA; petrous boneerosion Subocctpltat approach 2 x 2 cmtumor in the CPA Suboccipitat approach, 2 x 3 cm tumor in theCPA Large extradural tumor, temporal and suboccipital aoproaches: petrous bone ercston Extra-and intradural tumor, subtemporal andsuboccipitataoproaches.petrous bone destuenon Extradural MCFapproach; 4 x 4 cm MCFtumor, tegmen tympani erosion Combinedtrenspetrosal-transtentonalapproach 5 x 5 cm tumor in the CPA and 2 x 3 cm in MCF Extradural MCFapproach; tegrnen tympani ercson Extradural MCF approach; walnut sized tumcr, tegmen tympani erosion, smalldigitation intheauditoryintemal canal Extradural MCFapproach; walnut szed tumor, petrous bonedestructlon, smalldigitationin theauditory internal canal
Downloaded by: NYU. Copyrighted material.
182
lntrc craniat SChWOI11l0ma of litt'fcctol nert-e
The subtra etion teehni que may help to image the pathologieal vess els, as hap pen ed in one of our cases.
CT scanning is at pres ent the most importa nt investigati on in the work-up on cra nia l nerv e VII sch wa nno ma s becau se it defines the exa ct extent of the lesion, whi ch as a rule shows definit e enha ncement afte r int raven ou s contrast injection . reveaIing erosio n of the petrous bon e and the relati onships with the stru ctu res it contains . In both of our ease s the CT sean showed a small fingerlike proeess protruding into th e internal a uditory ea nal, whieh was enlarged with out th e tum our presentin g a ny inlradural developrnent . No data emerged from our review on the use of MRI in th ese lesions , altho ugh it cou ld prob ably eonlribute mueh 10 the pr eoperative diagno sis of cra nia l nerve VII schwannomas. just as it rep ortedly has in intrac rania l ne ur inomas ofo ther sites (4. 5). Since schwannomas of the facial nerv e gro wing into the midd le cra nial fossa usuall y remain extradural. the customa ry su rgieal approac h is a temporal cra niotomy with exposure of the tumou r by the extradural route (3,12, 23) .
Growth of the lesion within the petrou s bone may require the remo val of pa rt of it, som etim es as far as the internal auditory ca na l. In the rare ca ses in whieh the tumou r penetrates the intradural compa rtme nt at posterior cra nial fossa level, growing tow ards th e cere bello-pontine a ngle, a eombine d subtempo ral extradur al and suboeci pita l proeedure in two stages (1, 18) or in one stage (17) has been prop osed . In eases in whieh the lesion deve lops into the eerebello-pontine a ngle only (6,19,2 1), an a pproach simila r to the customa ry one for treating schwann omas of the era nial nerv e VIII has been used .
l~ ,\,1. Haughton. T. P. Xai dich: Cra nial a nd spina l magnetic resonance imaging. An atla s and guide . Raven Press ed .. Xew Yo rk, 198 7. eh . 8. p. 198 a nd 224 -231 s Elster. A. D.: Cranial magn eue resona nce ima ging . Churchill Livmgsto ne ed.. New Yo rk-Edinburgh -London- ~ Iel bou rn e (1988) 326-334 6 Gonzales-Pardo. L.. C. E. Hracket t. L. L. Lansky: Facia l schwa nnoma in a l ö-yea r-old girl. Child's Bra in 7 (1980) 220-224 7 /l ora. J. F.. A. K. Brown j r.: Neurilem moma of the faclal ner ve. Laryngo scope 74 (196 4) 134- 143 11 tsa mat . F.• F. Bartumeus. A. AI. sttranda. J. Prat. L. C. Pons: Neutinomas of the facial nerv e. J. Neurosu rg. 43 (97 5) 60 8- 6 13 9 Kleineesser. 0. . G. Friedm ann: Obe r Neurlno me des Nervus facialis. Zbl. Neuroch ir . 19 ( 959) 49 -59 10 Kett el. K.: Neurinoma of the facial ne rve. Arch. Otolar yngul. 44 (19461253-26 1 11 La tack; J. T.. T. O. Gabriets en. J. E. Knake. J. I•. Kemink; M. D. Graham. S . S. Gebarsk i. P. J. Yang: Facial nerv e neuromas: radl ologlc evaluatlon. Radi ology 149 (1983) 731 - 737 12 Ltliecutst. B.. C.A. Thulin. D. Tovi. lt . Wiberg. J. Ohman: Neur tnoma of the lab yrinthine portion of the facia l ne rve . J. Neurosarg . 37 (1972) 105-109 13 Liliequist. H.: Neutinomas of the labyrtnthine portion of the facia l ne rve cana l. Adv. Oto-Rhino -Laryngol. 24 (1978) 58 -67 1-4 Lin. S.. E. Go: Neurilemmo ma ofthe facial ne rve.Xeu roradiology 6 (1973) 185- 187 15 Lore, J. G.: Unila teral deafness and progr essive facia l palsy due to int rapetrous neurofibro ma : surgiealtreatme nt. Proe. Sta fT. Meet. Mavo CHn. 25 (19501 228-232 16 Muh lbauer. ,\ 1. 5.. 1\: c. Cle rk; 1. 11. Robertson . L. G. Gc rdne r. F. C. Dohan: Malignan t nerv e sheath tumour of the Iacia l nerv e: ca se re po rt and discussion. Neurosurgery 21 (1987) 68 - 73 17 Mur ata, T.. A. Hakuba. T. Okum ura. Mori Koreaki: Intrap etrous neur inom as ofthe facia l nerve. Rep ort of th ree eas es. Surg. Neurol. 23 (19851507-5 12 I H Nakao. S.. 7: Fukumi tsu , M. Oqata. T. Tabuchi: Facia l nerve schwannc mas: re port of two eases. No Shinkei Geka 12 0 9841 745-7 51 19 Ne dzelski. J. . C. Totor. Other cere bellopontine a ngle Inon-acoustlc ne ur ino ma) tumo urs. J . Otolaryng ol. 11 (198212 48 -2 52 20 /I.'eely . J. G.. B. R. lt lford: Facia l nerve neuro mas . Arch . Otolaryngol. 100(1974) 298-301 21 Pulec. J. L.: Facia l nerv e tumou rs . Ann. Otol. Rhinol. Laryngol. 78 (1969) 962 -982 22 Putec, J. L.: Facial ne rve neuroma. Laryngoscope 82 (19721 1160- 1176 23 Rcsenblum. B.. R. Daois. M. Camins: Middle fossa facia l sc hwan noma removed via the intracranial ext radura l approach : case report and revtew of the literature . Xeurosurgery 2 1 09871 739 -741 24 Soi to. 11.. A. Baxter: Undiagnose d int ra tem pora l facia l nerv e neur ilemm om a s. Arch . Otolary ngol. 95 (19721 4 15-419 2S Sch negg. J. F.. ,V. Tribolet: Neurinoma oft he facial nerv e associa ted with a pa rietal meningioma . Surg. Neurol. 2 1 (198 4) 19-22 26 Sham baugh. G. E. j r.. I. K. Ar enberq. P. L. lJam ey . G. E. vatoa ss ori: Faclal ne urilemmomas : a stud y of fou r diverse case s. Arch. Otolaryngol. 90 (19691 742-75 5 27 Stewart. /J. ll1.: Reeurrent facia l pa lsy a nd tumour . Arch. Otota ryngoI.83 (1966) 543-546 28 Teto. J. ,\ 1.. 11. Yeh. G. W. Mtller. S. Shahbabian: Intr a tempor al schwa nno ma of the facial nerve. Neurosu rgery 13 (1983 1186- 188 Z9 I\'adin. K.. 11. Wi/brand: The la byrtnthlne port ion of the facia l ea nal. A com pa rattve ra dioan atomic lnvestigatton. Acta Rad iol. lDiagn J 28(1987)17-23 4
Dantele. D. L..
References 1
Beaumotu. G. D.: Intratem poral facia l nerve neurinomata. J.
Otolaryngol . Soe. Aust ral. 82 (198 1) 39-4 2 2 Curtin. 1. M.. J. P. Lanigan: Neurilem moma of the se venth nerve with intr acra nial extensio n. J. La ryngol. Otol. 78 (1964 ) 212-2 19 3 Purtoto. L. T.: The neurosurgtcal as pect of sevent b ne rve neur ilemmom a. J. Neurosurg. 17 (1960) 7 12-735
183
P. Luna rdi Oepa rtm ent of'Neurological Seiences Neurosurgery Unlverslty of Rome MLa Saplenza " Viale dell'U niversitä 30/A 00 / 85 Rome/lt aly
Downloaded by: NYU. Copyrighted material.
a uditory disturban ces (10 55 of hearing andlor pa racusias), hemi facial sp asm a nd cere bellar signs . On admission 25 pa tients (92 .6 %) pr esented eranial nerve VII paresis, which was partial only in 3 eases (8, 12, ourease 1).lnvolvem ent of the nerv us inter mediu s with impa irment oftaste an d salivation (3, 12) a re frequent findi ngs , a nd likewise era nial nerve VIII involvem ent on the lesion side with consequent perceptive hypoacusia. The radi ological feat ures of cra nial nerve VII schwann oma s with intracr an ial growt h a re uniform a nd cha racte ristie in cas es in wh ich the tum our exten ds into the midd le era nial foss a. A vari abl e degr ee of erosion of the pet rou s bon e is deteetab le on tomography (11), Angiography, whieh aeeording to Mureta et al. (17) makes , togeth er with cr scanning, an importan t cont ribution to the topogra phie and differ ential diagnosis, often pr ovides indir ect evide nce of a space-occupying lesion in th e middl e cra nial fossa and a t tim es sho ws a pathologieal circulat ion su pplied by br an ehes of the ase ending pha ryn geal artery .
Ne/iroc hiru rgia .H f1 99 / J
Intracranial schwannoma of the facial nerve: Report of two cases and r eview ofthe literature G. Roccht.M. A rtico . P. l.unardi. F M. Gagliardi Departmen t of'Neurologtcal Seiences. Section of'Neuros urgery. University ofRome "La Sa pienza ". Rome. ltal y
Two cases of intr acra nial facial schwannoma growing from the labyrinthine portion of the facial nerve are report ed. The clinlcal. patho logical and diagnostic feat ures and treatme nt of these ra re lesions are discussed in the light of the most important literature on this topic.
Ein intrakranie lles Schwan nom d es Faz ialis - Bericht übe r 2 Fälle und Literatu rübersicht Zwei Fälle eines intra kra niellen Faz ialisSchwannoms werd en beschrieben, welches sich im Labyrinthgebiet des N. facialis entwickelte. Die klinische n, pathologischen und diagnostischen Besond erh eite n und die Beha ndlung diese r seltene n Fälle werden anha nd der bisher verö ffentlichten Liter atur besprochen. Key-Wor ds Facia l nerve - Schwa nnoma - Geniculate ganglion - Facial paresis
Introd uctio n Schwarmomas of the facial nerve are uncommon tum ours, accounting for about 0.8 % ofall intr apetrosal space -occupying lesion s (20, 22, 24 , 26). More tha n 160 cases hav e been reported , mainly by otologists (12,1 7, 18, 20 ,21 , 24 , 26, 271. Most of these tumo urs arise from the distal porti on of the nerve within the facial cana l, a few from the geniculate gan glion and hori zontal portion of the facial ca nal (2, 9, 12 , 15, 29). Very ra rely do these lesions have an intracranial development (1- 3, 6-9, 11- 13 , 15- 23, 25 , 27). 'Ne report two cases of facial nerve schwannoma with growth into the middle cra nial fossa and an alyze the clinical and ra diological featur es and tr eatment of these lesions by reviewing th e relevant pub lished work.
Neurochirurgta 34 (199 1) 180 -18 3 © Georg Thieme Verlag Stuttgart -Xew York
Case 1. A 16 yearol d male cam e to observation for a 5-month history of progressive peripheral pa resis of the right facial nerve and some loss of hearing in the right ear one month before admission. Neurological examination revealed severe pare sis of cra nial nerve VIIon the right side together with a perce ptive heari ng loss on the sa me side. Plain X-ray films of the skull showed a patch of erosion on the medial aspect ofthe dorsum oft he right petrous bone at tegmen tympa ni level. A CT br ain scan imaged a mass on the upper port ion oft he petrous bone and extending into the middle cra nial fossa (Fig. 1). After intravenous injection of contrast medium the lesion en ha nced appreciably. Angiogra phy of the cerebra l circulation revealed a slight upwa rd displacement of the distal bran ches of the sylvian complex on the sa me side. A right temporal cra niotomy followed by extradural exposur e disclosed a roundish walnut-sized lesion originati ng from the labyrinthin e portion oft he facial nerve sheat h. The tumou r. with the ap pea rance ofa schwa nnoma, protru ded into the middle cra nial fossa thr ough a c1earcut patch of bone ra refaction extending to the entire tegmen tympan i. Tumour removal was total and the facial nerve, though thinned and compressed by the lesion , was preserved. On histological examinatio n the tumour proved to be a typical schwannoma. The postoperative course was uneventful an d on discharge the facial par esis was uncha nged. At follow-up 8 months later the patient still had a slight facia l pa resis an d a CT sca n showe d no recur rence. Case 2. This 23 yea rol d malec onsulted us in June 1988 for a severe dista l pa resis of the left facial nerve of 3 year sta nding. One year before admission he bega n to complain hypoacusia on the sa me side. The clinical findings on admission were : complete paresis of the left facial nerve comb ined with a homolateral perceptive hearing loss. Plain X-ray films of the skull wer e unrema rka ble. Tomogra phy of the 1eftpctrous bone sho wed a patch of bone ra refaction on its upper wall. A CT brain scan revealed a mass on the floor of the middle cra nial Iossa aga inst the petrous bone, which was ero ded. The lesion enha nced on intr avenous injectlon of contras t an d a small fingerlike process could be see n protrud ing into the internal auditory ca nal (Fig. 2). Angiography with the subtractio n technique revealed a pathological circ ulation in the middle cra nial fossa during the capillary pha se IFig. 3A). The tympanie artery in the oblique view (Fig. 3B) was disp1aced upwards arc hwise .
Left temporal cra niotomy followed by extradural exposure revealed a tumour that seeme d to a rise from the petrous bone at tegmen tympan i level. The 1esion, the size ofa walnut, was growlng within the petrous bone to reac h the intern al a uditory ca nal. Although it was hard to distinguish from the facial ne rve, the tumour was re moved completely. The histological diagnosis was schwa nnoma. Because of the prot racted den ervation tha t had taken place before surgery. a facial-hypoglossal anasto mosis operation was not per formed.
Downloaded by: NYU. Copyrighted material.
Case Repor ts Su mmary
/I;'ell rochi ru rgi a 34 (1991)
Intracranial scluoannoma oj the[acia ! nerce
181
-
Fig. 1 Gase 1.Cl sean after mtravenousinlection of eontrast medium showing a mass loeated in the middle cranial tossa at the tegmentympani level
Downloaded by: NYU. Copyrighted material.
Fig. 3a
Fig. 2a
Fig.2b Fig. 2 Gase 2. Cl atterIntravencusiniection of eontrast mediumshowing in theaxial (A)scan anextradural (arrows)tumour onginatingfromthe labyrinthine po-nonof thepetrousboneandextendinginthemiddlecranialfossa and into the internal auditoryeanal (Iittlearrows).Note theremarkable erosion of thepetrous bone more evident in the eoronal (B)Cl scan
Fig. 3 b Fig.3 Gase 2.Selectiveangiography ot theexterne! earotidartery,acccmplished with thesubtraetiontechnique. showingapathclogicatcirculation(A)in themodleetamal fossa in thelateralview. Thetympanicartery is displaeed upwards archwise (arrows) in the oblique vew (B)
Discussion
S aito and Baxte r (24) consider tha t cranial nerve VII schwanno mas originate from the nervus intermedius at the point of connection with the geniculate ganglion and from aberrant ganglionic cells in the verticaJ portion of the nerve. More recently Rosenblum et al. (23) con-
firmed this interpretation. pomtmg out that tumou rs developing from the geniculate ganglion can easily grow towards the base ofthe skull through a zone ofleast resistance, na mely the thin bony lam ina overlying the ganglion, and so occupy an extrad ural intr acrani al site in the middle cra nial fossa.
Neurochirurgia 34 (1991J
G. Rocctü. M . Artico. P. Lunardi, F.M. Gaqliardi
Isamat et al. (8) argu ed thatlesions arising from the labyrinth ine portion of the facial nerve and from the geniculat e ganglion are stri ctly within the purview of neurosurgery and present a uniform clinical and radiologtcal patt ern. Cran ial nerve VII schwannomas with intra cra nial development are rarely encountered in neurosurgical practice, there being only 25 reported cases (Table I ) plus our own two. These tumours show no parti cular sex prefer ence: of the 27 cases covered by this review 15 were in fernales and 12 in males. The age rang e is from 4to 67 years with a mean age of 32 and a certain predileclion for the first two deca des oflife (8 cases out of2 7 or 29.6 %).
Table t
In 15 cases (2,3, 7- 9,12-15, 17,22-24,27 , 28) the lesion developed exd usively in the midd le cranial fossa, while in 6 cases it was confined to the cere bellopontine angle (6, 11, 19, 21), behaving clinically and radiologically like others spa ce-occupying lesions at that site. In the remain ing 4 cases the tumour present ed an hourglass development straddling the middle cranial and posterior cra nial fossa (I , 17, 18). In our two cases the tumour , though growing mainly in the middle cra nial fossa , present ed a small digitation into the internal auditory canal, but the lesion remain ed strictly extradural. The clinical history ran ged from 2 month s to 26 years with a mean duralion of 6.7 years. Clinical onset was ma rked in 15 cases (62.5%) by a peripheral paresis of cranial nerve VII on the lesion side. Other early signs were
27 Gases ot intracranial facial nerveschwannomas
Author
I Duration
I Surgical approachandtindings
I Dealness Facial peresis Feetal weakness
I Byrs
12yrs Byrs
I Extradural MCFapproach, petrous bone eroscn Extradural MCFapproach, eggsizedtumor Intradural MCF approach, tumor weight ,. 25 gm, petrous bone erosron Intradural temporal approach, cystic tumor Mastoidectomy, extradural MCF approach, tegmen tympani eroslcn. large tumor Mastoidectomy, extradural MCFapproach, petrousbone erosion Fronto-temporo-parietal craniotomy, lemon sized tumor Translabyrinthineapproach, CPA tumor 2.5 x 2.5 cm originatingft om thegeniculate ganglionandprotruding throughthe petrous bone Extradural MCF ecoroacn oetrous bone eroslon Extradural MCF eooroacn 1.0x 1.5cm Subtemporal craniotomy, 4 x 4 cm tumor Extradural MCFapproach, petrousbone8 x 10mm defect Subcccipitalapproach, audüorycanalunrootec.small
Clinical onset
l o,e,1950 Kleinsasser et al., 1959 Furlow, 1960
Curtin et al., 1964
20 F
Facial weakness Facial paralvsrs
Hora & Brown, 1964
37 F
Hearing loss and paracusias
2 yrs
Stewart. 1966 Pulec, 1972
38 M 55 F
Recurrent facial paresis Hearing 10 55 end paracusias
26y rs 2 yrs
Lihequist et al., 1972 lsamat et al, 1975
67 4 42 41
Facialpalsy and deafness Facial paresis Hearingloss Hemifacial spasm
7mo 3yrs 19 yrs
42 M
Deatness
15 yrs
Liliequist, 1978 Gonzalez-Pardo et al., 1980 Beaumont, 1981
19 M 16 F 14 M
Nedzelskiet al., 1982 Latack et al., 1983
31 F 58 F
Nakao et al., 1984
69 F 66 M 44 M
Facial paresrs 12 yrs Dizzinessandtacial palsy 2 mo Facial weaknessand hemifacial 3 yrs spasm Hearing loss andparacusias 5 yrs Hearing loss and hemifacial 2 yrs spasm Hearing loss 6 yrs Hearing loss 6mo Hearingloss, hemifacialspasm. 4 yrs tacial paresis Hearing difficultyand facial 17 yrs paresrs Faclal paresis 13yrs
44
M
5 yrs 15 yrs
F F F M
2.5 mo
tumcr
51 F Murata et al., 1985
39 F 30 F
Rosenblum et al., 1987
26 F
Ourcase 1
16 M
Our case 2
23 M
Paracusias. hearingloss,facial paresrs Progressivetaotat paresis. heanng lcss Progressivetacial paresisand deafness Facial paresis and deafness
10 mo
5mo 5mo 3 yrs
Temporal craniotomy, buge extradural tumor Suboccipitalcraniectomy,3 x 5 x 7 cmtumorin theCPA Suboccipitalcraniectomyand extradural MCF approach; small extradural tumor Suboccipital cramectorny. 3.5 x 3.5cm tumor intheCPA Suboccipttal craniectomy, 1; 2 x 1cmtumcr lntheCPA; petrous boneerosion Subocctpltat approach 2 x 2 cmtumor in the CPA Suboccipitat approach, 2 x 3 cm tumor in theCPA Large extradural tumor, temporal and suboccipital aoproaches: petrous bone ercston Extra-and intradural tumor, subtemporal andsuboccipitataoproaches.petrous bone destuenon Extradural MCFapproach; 4 x 4 cm MCFtumor, tegmen tympani erosion Combinedtrenspetrosal-transtentonalapproach 5 x 5 cm tumor in the CPA and 2 x 3 cm in MCF Extradural MCFapproach; tegrnen tympani ercson Extradural MCF approach; walnut sized tumcr, tegmen tympani erosion, smalldigitation intheauditoryintemal canal Extradural MCFapproach; walnut szed tumor, petrous bonedestructlon, smalldigitationin theauditory internal canal
Downloaded by: NYU. Copyrighted material.
182
lntrc craniat SChWOI11l0ma of litt'fcctol nert-e
The subtra etion teehni que may help to image the pathologieal vess els, as hap pen ed in one of our cases.
CT scanning is at pres ent the most importa nt investigati on in the work-up on cra nia l nerv e VII sch wa nno ma s becau se it defines the exa ct extent of the lesion, whi ch as a rule shows definit e enha ncement afte r int raven ou s contrast injection . reveaIing erosio n of the petrous bon e and the relati onships with the stru ctu res it contains . In both of our ease s the CT sean showed a small fingerlike proeess protruding into th e internal a uditory ea nal, whieh was enlarged with out th e tum our presentin g a ny inlradural developrnent . No data emerged from our review on the use of MRI in th ese lesions , altho ugh it cou ld prob ably eonlribute mueh 10 the pr eoperative diagno sis of cra nia l nerve VII schwannomas. just as it rep ortedly has in intrac rania l ne ur inomas ofo ther sites (4. 5). Since schwannomas of the facial nerv e gro wing into the midd le cra nial fossa usuall y remain extradural. the customa ry su rgieal approac h is a temporal cra niotomy with exposure of the tumou r by the extradural route (3,12, 23) .
Growth of the lesion within the petrou s bone may require the remo val of pa rt of it, som etim es as far as the internal auditory ca na l. In the rare ca ses in whieh the tumou r penetrates the intradural compa rtme nt at posterior cra nial fossa level, growing tow ards th e cere bello-pontine a ngle, a eombine d subtempo ral extradur al and suboeci pita l proeedure in two stages (1, 18) or in one stage (17) has been prop osed . In eases in whieh the lesion deve lops into the eerebello-pontine a ngle only (6,19,2 1), an a pproach simila r to the customa ry one for treating schwann omas of the era nial nerv e VIII has been used .
l~ ,\,1. Haughton. T. P. Xai dich: Cra nial a nd spina l magnetic resonance imaging. An atla s and guide . Raven Press ed .. Xew Yo rk, 198 7. eh . 8. p. 198 a nd 224 -231 s Elster. A. D.: Cranial magn eue resona nce ima ging . Churchill Livmgsto ne ed.. New Yo rk-Edinburgh -London- ~ Iel bou rn e (1988) 326-334 6 Gonzales-Pardo. L.. C. E. Hracket t. L. L. Lansky: Facia l schwa nnoma in a l ö-yea r-old girl. Child's Bra in 7 (1980) 220-224 7 /l ora. J. F.. A. K. Brown j r.: Neurilem moma of the faclal ner ve. Laryngo scope 74 (196 4) 134- 143 11 tsa mat . F.• F. Bartumeus. A. AI. sttranda. J. Prat. L. C. Pons: Neutinomas of the facial nerv e. J. Neurosu rg. 43 (97 5) 60 8- 6 13 9 Kleineesser. 0. . G. Friedm ann: Obe r Neurlno me des Nervus facialis. Zbl. Neuroch ir . 19 ( 959) 49 -59 10 Kett el. K.: Neurinoma of the facial ne rve. Arch. Otolar yngul. 44 (19461253-26 1 11 La tack; J. T.. T. O. Gabriets en. J. E. Knake. J. I•. Kemink; M. D. Graham. S . S. Gebarsk i. P. J. Yang: Facial nerv e neuromas: radl ologlc evaluatlon. Radi ology 149 (1983) 731 - 737 12 Ltliecutst. B.. C.A. Thulin. D. Tovi. lt . Wiberg. J. Ohman: Neur tnoma of the lab yrinthine portion of the facia l ne rve . J. Neurosarg . 37 (1972) 105-109 13 Liliequist. H.: Neutinomas of the labyrtnthine portion of the facia l ne rve cana l. Adv. Oto-Rhino -Laryngol. 24 (1978) 58 -67 1-4 Lin. S.. E. Go: Neurilemmo ma ofthe facial ne rve.Xeu roradiology 6 (1973) 185- 187 15 Lore, J. G.: Unila teral deafness and progr essive facia l palsy due to int rapetrous neurofibro ma : surgiealtreatme nt. Proe. Sta fT. Meet. Mavo CHn. 25 (19501 228-232 16 Muh lbauer. ,\ 1. 5.. 1\: c. Cle rk; 1. 11. Robertson . L. G. Gc rdne r. F. C. Dohan: Malignan t nerv e sheath tumour of the Iacia l nerv e: ca se re po rt and discussion. Neurosurgery 21 (1987) 68 - 73 17 Mur ata, T.. A. Hakuba. T. Okum ura. Mori Koreaki: Intrap etrous neur inom as ofthe facia l nerve. Rep ort of th ree eas es. Surg. Neurol. 23 (19851507-5 12 I H Nakao. S.. 7: Fukumi tsu , M. Oqata. T. Tabuchi: Facia l nerve schwannc mas: re port of two eases. No Shinkei Geka 12 0 9841 745-7 51 19 Ne dzelski. J. . C. Totor. Other cere bellopontine a ngle Inon-acoustlc ne ur ino ma) tumo urs. J . Otolaryng ol. 11 (198212 48 -2 52 20 /I.'eely . J. G.. B. R. lt lford: Facia l nerve neuro mas . Arch . Otolaryngol. 100(1974) 298-301 21 Pulec. J. L.: Facia l nerv e tumou rs . Ann. Otol. Rhinol. Laryngol. 78 (1969) 962 -982 22 Putec, J. L.: Facial ne rve neuroma. Laryngoscope 82 (19721 1160- 1176 23 Rcsenblum. B.. R. Daois. M. Camins: Middle fossa facia l sc hwan noma removed via the intracranial ext radura l approach : case report and revtew of the literature . Xeurosurgery 2 1 09871 739 -741 24 Soi to. 11.. A. Baxter: Undiagnose d int ra tem pora l facia l nerv e neur ilemm om a s. Arch . Otolary ngol. 95 (19721 4 15-419 2S Sch negg. J. F.. ,V. Tribolet: Neurinoma oft he facial nerv e associa ted with a pa rietal meningioma . Surg. Neurol. 2 1 (198 4) 19-22 26 Sham baugh. G. E. j r.. I. K. Ar enberq. P. L. lJam ey . G. E. vatoa ss ori: Faclal ne urilemmomas : a stud y of fou r diverse case s. Arch. Otolaryngol. 90 (19691 742-75 5 27 Stewart. /J. ll1.: Reeurrent facia l pa lsy a nd tumour . Arch. Otota ryngoI.83 (1966) 543-546 28 Teto. J. ,\ 1.. 11. Yeh. G. W. Mtller. S. Shahbabian: Intr a tempor al schwa nno ma of the facial nerve. Neurosu rgery 13 (1983 1186- 188 Z9 I\'adin. K.. 11. Wi/brand: The la byrtnthlne port ion of the facia l ea nal. A com pa rattve ra dioan atomic lnvestigatton. Acta Rad iol. lDiagn J 28(1987)17-23 4
Dantele. D. L..
References 1
Beaumotu. G. D.: Intratem poral facia l nerve neurinomata. J.
Otolaryngol . Soe. Aust ral. 82 (198 1) 39-4 2 2 Curtin. 1. M.. J. P. Lanigan: Neurilem moma of the se venth nerve with intr acra nial extensio n. J. La ryngol. Otol. 78 (1964 ) 212-2 19 3 Purtoto. L. T.: The neurosurgtcal as pect of sevent b ne rve neur ilemmom a. J. Neurosurg. 17 (1960) 7 12-735
183
P. Luna rdi Oepa rtm ent of'Neurological Seiences Neurosurgery Unlverslty of Rome MLa Saplenza " Viale dell'U niversitä 30/A 00 / 85 Rome/lt aly
Downloaded by: NYU. Copyrighted material.
a uditory disturban ces (10 55 of hearing andlor pa racusias), hemi facial sp asm a nd cere bellar signs . On admission 25 pa tients (92 .6 %) pr esented eranial nerve VII paresis, which was partial only in 3 eases (8, 12, ourease 1).lnvolvem ent of the nerv us inter mediu s with impa irment oftaste an d salivation (3, 12) a re frequent findi ngs , a nd likewise era nial nerve VIII involvem ent on the lesion side with consequent perceptive hypoacusia. The radi ological feat ures of cra nial nerve VII schwann oma s with intracr an ial growt h a re uniform a nd cha racte ristie in cas es in wh ich the tum our exten ds into the midd le era nial foss a. A vari abl e degr ee of erosion of the pet rou s bon e is deteetab le on tomography (11), Angiography, whieh aeeording to Mureta et al. (17) makes , togeth er with cr scanning, an importan t cont ribution to the topogra phie and differ ential diagnosis, often pr ovides indir ect evide nce of a space-occupying lesion in th e middl e cra nial fossa and a t tim es sho ws a pathologieal circulat ion su pplied by br an ehes of the ase ending pha ryn geal artery .
Ne/iroc hiru rgia .H f1 99 / J
