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Cystic cavernous malformation of the cerebellopontine angle
Clinical Neurology and Neurosurgery 100 (1998) 133 – 137
Case report
Cystic cavernous malformation of the cerebellopontine angle Girish Vithalachar Vajramani a, B. Indira Devi a,*, Thimappa Hegde a, S.G. Srikanth b, S.K. Shankar c a
Department of Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, 560 029, India Department of Neuroradiology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560 029, India c Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560 029, India b
Received 17 November 1997; received in revised form 20 January 1998; accepted 4 February 1998
Abstract A 46 year old male presented with a cerebellopontine angle syndrome. CT scan and MRI revealed a cystic mass with a solid nodule in the cerebellopontine angle. At surgery, a vascular lesion was encountered which was totally excised in two stages. The histopathology was consistent with that of a cavernous malformation. Only four such cases have been reported so far in the English literature. The clinical and radiological features and the surgical management are discussed. © 1998 Elsevier Science B.V. All rights reserved. Keywords: Cavernous malformation; Cyst; Cerebellopontine angle; Computed tomographic (CT) scan; Magnetic resonance imaging (MRI)
1. Introduction
2. Case report
Cavernous malformations comprise 10 – 15% of both intracranial and spinal vascular malformations [1]. Though most commonly located supratentorially, they are also encountered in the brainstem, cerebellum, cranial nerves, dura and venous sinuses [2]. With contemporary imaging techniques cavernous malformations are being recognized with increasing frequency. We report a case of a cavernous malformation occurring in the cerebellopontine angle. Only four cases of cavernous malformation situated in the cerebellopontine angle have been reported [3 – 6]. Definite diagnosis in all cases was established after histopathological examination of the resected lesion.
A 46 year old male presented to the neurosurgical services of National Institute of Mental Health and Neuro Sciences with complaints of tinnitus in right ear for 7 months, headache since 6 months, clumsiness of right upper and lower limbs and difficulty with walking of 15 days duration. General physical examination was normal. There was no evidence of neurocutaneous markers. Neurologically, he was conscious, alert and oriented. His speech was slurred. Fundoscopy was normal. He had bilateral horizontal gaze-dependent nystagmus, right sided sensorineural hearing loss and cerebellar signs. A clinical diagnosis of right cerebellopontine angle syndrome was made. Audiogram showed severe sensorineural hearing loss on the right side. Cranial computed tomographic (CT) scan revealed an isodense contrast enhancing lesion in the right cerebellopontine angle with a cyst capping the tumor. The fourth ventricle was compressed and the ipsilateral
* Corresponding author. Tel.: +91 80 664212, ext. 203; fax: + 91 80 6631830; e-mail: [email protected] 0303-8467/98/$19.00 © 1998 Elsevier Science B.V. All rights reserved. PII S0303-8467(98)00016-X
134
G. Vithalachar Vajramani et al. / Clinical Neurology and Neurosurgery 100 (1998) 133–137
pre-pontine cistern was widened. There was no evidence of enlargement of internal auditory meatus (Fig. 1a). He underwent right retromastoid suboccipital craniectomy. At surgery the internal auditory meatus and the jugular foramen were normal. The 7th and 8th cranial nerves were free on dissecting the arachnoid. There was a beefy red tumor lateral to the brain stem in the cerebellopontine angle over the cranial nerves. It could be dissected off easily. The tumor was extremely vascular and only partial decompression was done. Post operative CT scan showed the residual tumor. Magnetic resonance imaging (MRI) was done for better delineation of the lesion. It revealed a large hypointense cystic lesion with an isointense solid component anteriorly in the right cerebellopontine angle on spin echo T1 weighted sequence (Fig. 1b). The cystic portion was hyperintense on turbo spin echo T2 weightage and the solid component was isointense with flow voids probably suggesting blood vessels (Fig. 1c). On flash 2D sequence (Fig. 1d), the cystic portion was hyperintense — the solid portion was not delineated. There was no evidence of blood or blood products within the lesion. The patient underwent reexploration through the previous craniectomy with total excision of the tumor. This time the cyst was entered transparenchymally and the tumor, which was freed from the adjacent structures during the previous surgery, was excised in toto. Postoperatively, patient had improved hearing and tinnitus had disappeared. Audiometry, however showed persistent sensorineural hearing loss. He was discharged on the 7th postoperative day without any further neurological deficits. Repeat enhanced cranial CT scan showed evidence of total excision.
4. Discussion Cavernous malformations are well circumscribed vascular malformations composed of dense cluster of honeycomb-like, thin walled vascular channels without intervening neuroglial parenchyma [1]. They may arise from any location in the central or peripheral nervous system. Infratentorial cavernous malformations account for about 25% of intracranial lesions, most of them arising in the brainstem and the cerebellum [2]. Occurrence in an extra-axial location is also known, accounting for about 13%, the majority of them arising from the middle fossa/cavernous sinus [7,8]. About 16 cases of cavernous hemangiomas involving the internal auditory meatus have been reported [9–16]. However extra-axial cavernous angiomas in the CP angle are exceedingly rare. Only four cases have been reported so far in the English literature [3–6]. Details of the reported cases and the present case are summarized in the Table 1. Two of these and the present case had a cystic component where as the other two were solid. Only a few cases of cavernous malformation with large cysts have been reported [4,5,17–20]. Steiger and coworkers feel that the intraparenchymal cystic form is particularly prone to growth and thus frequently presents clinically with a progressive neurological deficit [20]. The inner surface of the cyst is covered by endothelium-derived cells and the cyst formation origi-
3. Histopathology The vascular mass resected in both instances was formalin-fixed, processed for paraffin sectioning, and stained with Haematoxylin-Eosin, Masson’s trichrome and Verhoef Van Gieson. The sections revealed numerous cavernous vascular channels, with an island of distorted and atrophic cerebellar folia. In focal areas, the vascular mass was sclerosed and small lumps of hemosiderin were deposited on the collagen. The lesion had numerous cavernous spaces, lined by endothelium and separated by collagenous septae with no intervening neural tissue (Fig. 2a and b. At places the septae of the malformation were incomplete forming large blood filled cystic spaces. Randomly intermingled with these, areas of telengiectatic capillaries and partially throm bosed veins, with variable mural calcification, were seen, representing an associated venous malformation. The histological features of the lesion were characteristic of cavernous angioma associated with venous malformation.
Fig. 1. (a) Axial contrast enhanced cranial CT scan showing a heterogenous mass lesion with solid and cystic components in the right CP angle. (b) Axial MRI (SE T1WI) showing an isointense lesion surrounded by a large cystic component in the right CP angle with compression of the brain stem. (c) Coronal MR section (Turbospin echo T2WI) showing mildly hyperintense solid component inferiorly (arrowhead). (d) Axial MRI (flash 2D T2WI) showing a large hyperintense lesion in the right CP angle.
Age/sex
37/m
30/m
60/m
32/m
46/m
Author/year
Dale, 1968 [3]
Iplikcioglu, 1986 [4]
Brunori, 1996 [5]
Kim, 1997 [6]
Present Case, 1997
Radiological investigations
Contrast study of posterior fossa showing filling defect. Progressive hearing loss, headache, ataxia Lt fa- Skull X-ray normal CT scan: Solid and cystic comcial palsy, bilateral papilloedema, Lt hearing ponent, calcification++ enhancement of cyst loss, V1 and V2 sensory loss. wall++. Rt facial numbness tinnitus, hearing loss vertigo, MRI: Lobulated mass with cysts (T1 and T2 hyper5th, 6th, 7th, 8th nerve palsy, Rt cerebellar intense contents). The solid component enhanced signs. with gadolinium hypointense rim bordering the tumor++. Angiography: Avascular. Lt facial numbness and sensory loss, bilateral CT: 2 cm hyperdense, irregular mass, no focal calSN hearing loss. cification. Angiogram: Avascular. MRI: Extraaxial lesion with irregular frond-like margins. Within the lesion haemorrhagic areas present hypointense rim bordering the tumor++. Headache, tinnitus, Rt SN hearing loss Rt cere- CT: Isodense enhancing mass lesion with hypodense bellar signs. cyst surrounding it. MRI: Isointense solid component with hypointense cyst on T1WI. On turbo spin echo T2WI the solid component was isointense and the cystic component hyperintense. No evidence of blood products on flash 2D sequence.
Light headedness tinnitus, impaired hearing.
Signs/symptoms
Table 1 Extra-axial cavernous malformation of the cerebellopontine angle
Beefy red tumor lateral to the brain stem in the CP angle over the cranial nerves. The tumor was vascular and was excised in two stages.
Firm mass, blue/grey, presence of large surface veins. Mass indenting and adherent to pons piece removal.
Middle fossa approach. Tiny CA found just above 7th and 8th Cr nerve. Bluish grey extramedullary cystic mass with xanthochromic fluid. The mass was adherent to 7th/8th nerve. Postop 7th and 8th nerve palsy. Reddish-blue, mulberry like lesion adherent to the brain stem and 7th and 8th cranial nerve. Presence of xanthochromic fluid++.
Surgical findings
G. Vithalachar Vajramani et al. / Clinical Neurology and Neurosurgery 100 (1998) 133–137 135
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Fig. 2. (a) Low power view of the cavernous malformation entrapping distorted cerebellar folia. Small arrows mark the area corresponding to the cystic zone. Area enclosed between large arrow heads is represented in part (b). (b) Cavernous vascular channels with collagenous walls, lined by flattened endothelium. A tiny island of gliosed parenchyma is entrapped on the left.
nates from decompensated sinusoids and possible rupture of septa between adjacent sinusoids [20]. This probably holds true also for extra-axial cystic cavernous malformation, as more space is available for their growth. Though the CT findings are non specific, the ability of CT to detect cavernous malformation is reportedly excellent [21,22]. Pre-contrast CT may show a lesion which is hyperdense or of mixed density, with improved delineation and faint enhancement on contrast administration [21,22]. Some times it is difficult to differentiate glioma or infarction from angioma by CT criteria alone [23]. Sensitivity of MRI to detect intraparenchymal cavernous malformation is very high, however in extraparenchymal cavernous malformation, the findings are nonspecific [6]. Pre-operative MRI was done in two of the previous cases and postoperatively in the present case. The solid component was isointense in both T1WI and T2WI in the present case and the case reported by Kim et al. [6]. Variable enhancement with gadolinium, depends upon the degree of thrombosis. Brunori et al. found
intense gadolinium enhancement whereas Kim et al. did not find any gadolinium enhancement [5,6]. Lesional haemorrhage was found in only one case [6]. The cyst showed hypointensity and hyperintensity in T1WI and T2WI respectively in the present case whereas it was hyperintense in both T1WI and T2WI in the case reported by Brunori et al. [5]. Hypointense rim bordering the lesion in the T2WI was found in two cases [5,6]. In the present case, we could not detect any blood products on imaging studies despite the histological evidence of haemosiderrin on the collagenous walls. Total excision, if possible, is the treatment of choice. Extra-axial cavernous malformations are said to be associated with higher peri-operative morbidity and mortality. This could be due to incomplete encapsulation and proximity or invasion of sinuses e.g. cavernous sinus. Excision of a cystic cavernous malformation is probably not difficult. Decompression of the cyst gives space for excision of the solid component. Total excision of the cyst wall itself may not be feasible in all the cases due to the presence of adhesions to vital structures in the cerebellopontine angle. In the present case, the large cyst wall was adherent to the cerebellar parenchyma. At second surgery the lesion was approached transparenchymally, through the cyst. This probably accounted for the presence of small islands of entrapped atrophic cerebellar tissue. However, unless the cyst wall is carefully searched for and the solid component is totally excised [7]; the treatment is likely to be incomplete.
References [1] Martin NA, Vinters H. Pathology and grading of intracranial vascular malformation. In: Barrow DL, editor. Intracranial Vascular Malformation. Park Ridge, IL: AANS 1990:1 – 30. [2] McCormick PC, Michelson WJ. Management of intracranial cavernous and venous malformation. In: Barrow DL, editor. Intracranial Vascular Malformation. Park Ridge, IL: AANS 1990:197 – 217. [3] Dale AJD. The cerebellopontine angle syndrome. Med Clin North Am 1968;52:789 – 95. [4] Iplikcioglu AC, Benli K, Bertan V, Ruacan S. Cystic cavernous hemangioma of the cerebellopontine angle. Case report. Neurosurgery 1986;19:641 – 2. [5] Brunori A, Chiapetta F. Cystic extra-axial cavernoma of the cerebellopontine angle. Surg Neurol 1996;46:475 – 6. [6] Kim M, Rowed DW, Cheung G, Ang LC. Cavernous malformation presenting as an extra-axial cerebellopontine angle mass. Case report. Neurosurgery 1997;40:187 – 90. [7] Mori K, Handa H, Hidefuku Gi, Mori K. Cavernoma in the middle fossa. Surg Neurol 1980;19:379 – 88. [8] Namba S. Extracerebral cavernous hemangioma of the middle cranial fossa. Surg Neurol 1983;19:379 – 88. [9] Babu R, Ransohoff J, Cohen N, Zagzag D. Cavernous angiomas of the internal auditory canal: Acase report and review of literature. Acta Neurochir (Wien) 1994;129:100 – 4.
G. Vithalachar Vajramani et al. / Clinical Neurology and Neurosurgery 100 (1998) 133–137 [10] Bordi L, Pires M, Symon L, Cheesman AD. Cavernous angioma of the cerebellopontine angle: a case report. Br J Neurosurg 1991;5:83 – 6. [11] Brackmann DE, Bartels LJ. Rare tumours of the cerebellopontine angle. Otolaryngol Head Neck Surg 1980;88:555–9. [12] Jacobson J, Reams C. Neurological disease in four patients with audiometric findings. Am J Otol 1991;12:114–8. [13] Mangham CA, Carberry JN, Brackmann DE. Management of infratemporal vascular tumors. Laryngoscope 1981;91:867 – 76. [14] Matia-Guiu X, Alejo M, Sole T, Ferrer I, Boboa R, Bartumeus F. Cavernous angiomas of the cranial nerves. Report of two cases. J Neurosurg 1990;73:620–2. [15] Pappas DG, Schneidermann TS, Brackman DE, Simpson LC, Chandra-sekar B, Sofferman RA. Cavernous hemangiomas of the internal auditory canal. Otolaryngol Head Neck Surg 1989;101:27 – 32. [16] Sundaresan N, Eller T, Ciric T. Hemangiomas of the internal auditory canal. Surg Neurol 1976;6:119–21.
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[17] Khosla VK, Banerjee AK, Mathuriya SN, Mehta S. Giant cystic cavernoma in a child. Case report. J Neurosurg 1984;60:1297–9. [18] Ramina R, Ingunza W, Vonofakos D. Cystic cerebral cavernous angioma with dense calcification. Case report. J Neurosurg 1980;52:259 – 62. [19] Vaquero J, Cabezudo JM, Leunda G. Cystic cavernous hemangioma of the brain. Acta Neurochir (Wien) 1983;67:135–8. [20] Steiger HJ, Markwalder TM, Reulen HJ. Clinicopathological relation of cerebral cavernous angiomas. Observations in eleven cases. Neurosurgery 1987;21:879 – 84. [21] Savoiardo M, Strada L, Passerini A. Intracranial cavernous hemangiomas: neuroradiologic review of 36 operated cases. Am J Neuroradiol 1983;4:945 – 50. [22] Tagle P, Huete I, Mendez J, Villar SD. Intracranial cavernous angioma: presentation and management. J Neurosurg 1986;64:720 – 3. [23] Rigamonti D, Drayer BP, Johnson PC, Hadley MN, Zabramski J, Spetzler RF. The MRI appearance of cavernous malformations (angiomas). J Neurosurg 1987;67:518 – 24.
Case report
Cystic cavernous malformation of the cerebellopontine angle Girish Vithalachar Vajramani a, B. Indira Devi a,*, Thimappa Hegde a, S.G. Srikanth b, S.K. Shankar c a
Department of Neurosurgery, National Institute of Mental Health and Neuro Sciences, Bangalore, 560 029, India Department of Neuroradiology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560 029, India c Department of Neuropathology, National Institute of Mental Health and Neuro Sciences, Bangalore, 560 029, India b
Received 17 November 1997; received in revised form 20 January 1998; accepted 4 February 1998
Abstract A 46 year old male presented with a cerebellopontine angle syndrome. CT scan and MRI revealed a cystic mass with a solid nodule in the cerebellopontine angle. At surgery, a vascular lesion was encountered which was totally excised in two stages. The histopathology was consistent with that of a cavernous malformation. Only four such cases have been reported so far in the English literature. The clinical and radiological features and the surgical management are discussed. © 1998 Elsevier Science B.V. All rights reserved. Keywords: Cavernous malformation; Cyst; Cerebellopontine angle; Computed tomographic (CT) scan; Magnetic resonance imaging (MRI)
1. Introduction
2. Case report
Cavernous malformations comprise 10 – 15% of both intracranial and spinal vascular malformations [1]. Though most commonly located supratentorially, they are also encountered in the brainstem, cerebellum, cranial nerves, dura and venous sinuses [2]. With contemporary imaging techniques cavernous malformations are being recognized with increasing frequency. We report a case of a cavernous malformation occurring in the cerebellopontine angle. Only four cases of cavernous malformation situated in the cerebellopontine angle have been reported [3 – 6]. Definite diagnosis in all cases was established after histopathological examination of the resected lesion.
A 46 year old male presented to the neurosurgical services of National Institute of Mental Health and Neuro Sciences with complaints of tinnitus in right ear for 7 months, headache since 6 months, clumsiness of right upper and lower limbs and difficulty with walking of 15 days duration. General physical examination was normal. There was no evidence of neurocutaneous markers. Neurologically, he was conscious, alert and oriented. His speech was slurred. Fundoscopy was normal. He had bilateral horizontal gaze-dependent nystagmus, right sided sensorineural hearing loss and cerebellar signs. A clinical diagnosis of right cerebellopontine angle syndrome was made. Audiogram showed severe sensorineural hearing loss on the right side. Cranial computed tomographic (CT) scan revealed an isodense contrast enhancing lesion in the right cerebellopontine angle with a cyst capping the tumor. The fourth ventricle was compressed and the ipsilateral
* Corresponding author. Tel.: +91 80 664212, ext. 203; fax: + 91 80 6631830; e-mail: [email protected] 0303-8467/98/$19.00 © 1998 Elsevier Science B.V. All rights reserved. PII S0303-8467(98)00016-X
134
G. Vithalachar Vajramani et al. / Clinical Neurology and Neurosurgery 100 (1998) 133–137
pre-pontine cistern was widened. There was no evidence of enlargement of internal auditory meatus (Fig. 1a). He underwent right retromastoid suboccipital craniectomy. At surgery the internal auditory meatus and the jugular foramen were normal. The 7th and 8th cranial nerves were free on dissecting the arachnoid. There was a beefy red tumor lateral to the brain stem in the cerebellopontine angle over the cranial nerves. It could be dissected off easily. The tumor was extremely vascular and only partial decompression was done. Post operative CT scan showed the residual tumor. Magnetic resonance imaging (MRI) was done for better delineation of the lesion. It revealed a large hypointense cystic lesion with an isointense solid component anteriorly in the right cerebellopontine angle on spin echo T1 weighted sequence (Fig. 1b). The cystic portion was hyperintense on turbo spin echo T2 weightage and the solid component was isointense with flow voids probably suggesting blood vessels (Fig. 1c). On flash 2D sequence (Fig. 1d), the cystic portion was hyperintense — the solid portion was not delineated. There was no evidence of blood or blood products within the lesion. The patient underwent reexploration through the previous craniectomy with total excision of the tumor. This time the cyst was entered transparenchymally and the tumor, which was freed from the adjacent structures during the previous surgery, was excised in toto. Postoperatively, patient had improved hearing and tinnitus had disappeared. Audiometry, however showed persistent sensorineural hearing loss. He was discharged on the 7th postoperative day without any further neurological deficits. Repeat enhanced cranial CT scan showed evidence of total excision.
4. Discussion Cavernous malformations are well circumscribed vascular malformations composed of dense cluster of honeycomb-like, thin walled vascular channels without intervening neuroglial parenchyma [1]. They may arise from any location in the central or peripheral nervous system. Infratentorial cavernous malformations account for about 25% of intracranial lesions, most of them arising in the brainstem and the cerebellum [2]. Occurrence in an extra-axial location is also known, accounting for about 13%, the majority of them arising from the middle fossa/cavernous sinus [7,8]. About 16 cases of cavernous hemangiomas involving the internal auditory meatus have been reported [9–16]. However extra-axial cavernous angiomas in the CP angle are exceedingly rare. Only four cases have been reported so far in the English literature [3–6]. Details of the reported cases and the present case are summarized in the Table 1. Two of these and the present case had a cystic component where as the other two were solid. Only a few cases of cavernous malformation with large cysts have been reported [4,5,17–20]. Steiger and coworkers feel that the intraparenchymal cystic form is particularly prone to growth and thus frequently presents clinically with a progressive neurological deficit [20]. The inner surface of the cyst is covered by endothelium-derived cells and the cyst formation origi-
3. Histopathology The vascular mass resected in both instances was formalin-fixed, processed for paraffin sectioning, and stained with Haematoxylin-Eosin, Masson’s trichrome and Verhoef Van Gieson. The sections revealed numerous cavernous vascular channels, with an island of distorted and atrophic cerebellar folia. In focal areas, the vascular mass was sclerosed and small lumps of hemosiderin were deposited on the collagen. The lesion had numerous cavernous spaces, lined by endothelium and separated by collagenous septae with no intervening neural tissue (Fig. 2a and b. At places the septae of the malformation were incomplete forming large blood filled cystic spaces. Randomly intermingled with these, areas of telengiectatic capillaries and partially throm bosed veins, with variable mural calcification, were seen, representing an associated venous malformation. The histological features of the lesion were characteristic of cavernous angioma associated with venous malformation.
Fig. 1. (a) Axial contrast enhanced cranial CT scan showing a heterogenous mass lesion with solid and cystic components in the right CP angle. (b) Axial MRI (SE T1WI) showing an isointense lesion surrounded by a large cystic component in the right CP angle with compression of the brain stem. (c) Coronal MR section (Turbospin echo T2WI) showing mildly hyperintense solid component inferiorly (arrowhead). (d) Axial MRI (flash 2D T2WI) showing a large hyperintense lesion in the right CP angle.
Age/sex
37/m
30/m
60/m
32/m
46/m
Author/year
Dale, 1968 [3]
Iplikcioglu, 1986 [4]
Brunori, 1996 [5]
Kim, 1997 [6]
Present Case, 1997
Radiological investigations
Contrast study of posterior fossa showing filling defect. Progressive hearing loss, headache, ataxia Lt fa- Skull X-ray normal CT scan: Solid and cystic comcial palsy, bilateral papilloedema, Lt hearing ponent, calcification++ enhancement of cyst loss, V1 and V2 sensory loss. wall++. Rt facial numbness tinnitus, hearing loss vertigo, MRI: Lobulated mass with cysts (T1 and T2 hyper5th, 6th, 7th, 8th nerve palsy, Rt cerebellar intense contents). The solid component enhanced signs. with gadolinium hypointense rim bordering the tumor++. Angiography: Avascular. Lt facial numbness and sensory loss, bilateral CT: 2 cm hyperdense, irregular mass, no focal calSN hearing loss. cification. Angiogram: Avascular. MRI: Extraaxial lesion with irregular frond-like margins. Within the lesion haemorrhagic areas present hypointense rim bordering the tumor++. Headache, tinnitus, Rt SN hearing loss Rt cere- CT: Isodense enhancing mass lesion with hypodense bellar signs. cyst surrounding it. MRI: Isointense solid component with hypointense cyst on T1WI. On turbo spin echo T2WI the solid component was isointense and the cystic component hyperintense. No evidence of blood products on flash 2D sequence.
Light headedness tinnitus, impaired hearing.
Signs/symptoms
Table 1 Extra-axial cavernous malformation of the cerebellopontine angle
Beefy red tumor lateral to the brain stem in the CP angle over the cranial nerves. The tumor was vascular and was excised in two stages.
Firm mass, blue/grey, presence of large surface veins. Mass indenting and adherent to pons piece removal.
Middle fossa approach. Tiny CA found just above 7th and 8th Cr nerve. Bluish grey extramedullary cystic mass with xanthochromic fluid. The mass was adherent to 7th/8th nerve. Postop 7th and 8th nerve palsy. Reddish-blue, mulberry like lesion adherent to the brain stem and 7th and 8th cranial nerve. Presence of xanthochromic fluid++.
Surgical findings
G. Vithalachar Vajramani et al. / Clinical Neurology and Neurosurgery 100 (1998) 133–137 135
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G. Vithalachar Vajramani et al. / Clinical Neurology and Neurosurgery 100 (1998) 133–137
Fig. 2. (a) Low power view of the cavernous malformation entrapping distorted cerebellar folia. Small arrows mark the area corresponding to the cystic zone. Area enclosed between large arrow heads is represented in part (b). (b) Cavernous vascular channels with collagenous walls, lined by flattened endothelium. A tiny island of gliosed parenchyma is entrapped on the left.
nates from decompensated sinusoids and possible rupture of septa between adjacent sinusoids [20]. This probably holds true also for extra-axial cystic cavernous malformation, as more space is available for their growth. Though the CT findings are non specific, the ability of CT to detect cavernous malformation is reportedly excellent [21,22]. Pre-contrast CT may show a lesion which is hyperdense or of mixed density, with improved delineation and faint enhancement on contrast administration [21,22]. Some times it is difficult to differentiate glioma or infarction from angioma by CT criteria alone [23]. Sensitivity of MRI to detect intraparenchymal cavernous malformation is very high, however in extraparenchymal cavernous malformation, the findings are nonspecific [6]. Pre-operative MRI was done in two of the previous cases and postoperatively in the present case. The solid component was isointense in both T1WI and T2WI in the present case and the case reported by Kim et al. [6]. Variable enhancement with gadolinium, depends upon the degree of thrombosis. Brunori et al. found
intense gadolinium enhancement whereas Kim et al. did not find any gadolinium enhancement [5,6]. Lesional haemorrhage was found in only one case [6]. The cyst showed hypointensity and hyperintensity in T1WI and T2WI respectively in the present case whereas it was hyperintense in both T1WI and T2WI in the case reported by Brunori et al. [5]. Hypointense rim bordering the lesion in the T2WI was found in two cases [5,6]. In the present case, we could not detect any blood products on imaging studies despite the histological evidence of haemosiderrin on the collagenous walls. Total excision, if possible, is the treatment of choice. Extra-axial cavernous malformations are said to be associated with higher peri-operative morbidity and mortality. This could be due to incomplete encapsulation and proximity or invasion of sinuses e.g. cavernous sinus. Excision of a cystic cavernous malformation is probably not difficult. Decompression of the cyst gives space for excision of the solid component. Total excision of the cyst wall itself may not be feasible in all the cases due to the presence of adhesions to vital structures in the cerebellopontine angle. In the present case, the large cyst wall was adherent to the cerebellar parenchyma. At second surgery the lesion was approached transparenchymally, through the cyst. This probably accounted for the presence of small islands of entrapped atrophic cerebellar tissue. However, unless the cyst wall is carefully searched for and the solid component is totally excised [7]; the treatment is likely to be incomplete.
References [1] Martin NA, Vinters H. Pathology and grading of intracranial vascular malformation. In: Barrow DL, editor. Intracranial Vascular Malformation. Park Ridge, IL: AANS 1990:1 – 30. [2] McCormick PC, Michelson WJ. Management of intracranial cavernous and venous malformation. In: Barrow DL, editor. Intracranial Vascular Malformation. Park Ridge, IL: AANS 1990:197 – 217. [3] Dale AJD. The cerebellopontine angle syndrome. Med Clin North Am 1968;52:789 – 95. [4] Iplikcioglu AC, Benli K, Bertan V, Ruacan S. Cystic cavernous hemangioma of the cerebellopontine angle. Case report. Neurosurgery 1986;19:641 – 2. [5] Brunori A, Chiapetta F. Cystic extra-axial cavernoma of the cerebellopontine angle. Surg Neurol 1996;46:475 – 6. [6] Kim M, Rowed DW, Cheung G, Ang LC. Cavernous malformation presenting as an extra-axial cerebellopontine angle mass. Case report. Neurosurgery 1997;40:187 – 90. [7] Mori K, Handa H, Hidefuku Gi, Mori K. Cavernoma in the middle fossa. Surg Neurol 1980;19:379 – 88. [8] Namba S. Extracerebral cavernous hemangioma of the middle cranial fossa. Surg Neurol 1983;19:379 – 88. [9] Babu R, Ransohoff J, Cohen N, Zagzag D. Cavernous angiomas of the internal auditory canal: Acase report and review of literature. Acta Neurochir (Wien) 1994;129:100 – 4.
G. Vithalachar Vajramani et al. / Clinical Neurology and Neurosurgery 100 (1998) 133–137 [10] Bordi L, Pires M, Symon L, Cheesman AD. Cavernous angioma of the cerebellopontine angle: a case report. Br J Neurosurg 1991;5:83 – 6. [11] Brackmann DE, Bartels LJ. Rare tumours of the cerebellopontine angle. Otolaryngol Head Neck Surg 1980;88:555–9. [12] Jacobson J, Reams C. Neurological disease in four patients with audiometric findings. Am J Otol 1991;12:114–8. [13] Mangham CA, Carberry JN, Brackmann DE. Management of infratemporal vascular tumors. Laryngoscope 1981;91:867 – 76. [14] Matia-Guiu X, Alejo M, Sole T, Ferrer I, Boboa R, Bartumeus F. Cavernous angiomas of the cranial nerves. Report of two cases. J Neurosurg 1990;73:620–2. [15] Pappas DG, Schneidermann TS, Brackman DE, Simpson LC, Chandra-sekar B, Sofferman RA. Cavernous hemangiomas of the internal auditory canal. Otolaryngol Head Neck Surg 1989;101:27 – 32. [16] Sundaresan N, Eller T, Ciric T. Hemangiomas of the internal auditory canal. Surg Neurol 1976;6:119–21.
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[17] Khosla VK, Banerjee AK, Mathuriya SN, Mehta S. Giant cystic cavernoma in a child. Case report. J Neurosurg 1984;60:1297–9. [18] Ramina R, Ingunza W, Vonofakos D. Cystic cerebral cavernous angioma with dense calcification. Case report. J Neurosurg 1980;52:259 – 62. [19] Vaquero J, Cabezudo JM, Leunda G. Cystic cavernous hemangioma of the brain. Acta Neurochir (Wien) 1983;67:135–8. [20] Steiger HJ, Markwalder TM, Reulen HJ. Clinicopathological relation of cerebral cavernous angiomas. Observations in eleven cases. Neurosurgery 1987;21:879 – 84. [21] Savoiardo M, Strada L, Passerini A. Intracranial cavernous hemangiomas: neuroradiologic review of 36 operated cases. Am J Neuroradiol 1983;4:945 – 50. [22] Tagle P, Huete I, Mendez J, Villar SD. Intracranial cavernous angioma: presentation and management. J Neurosurg 1986;64:720 – 3. [23] Rigamonti D, Drayer BP, Johnson PC, Hadley MN, Zabramski J, Spetzler RF. The MRI appearance of cavernous malformations (angiomas). J Neurosurg 1987;67:518 – 24.