- Email: [email protected]
Aneurysm of the anterior inferior cerebellar artery (AICA) associated with high-flow lesion: reportof two cases and review of literature
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was completely excised in two stages. A complete resection of a lipoblastoma is feasible and advantageous with no need for a mutilating radical excision. A recurrence rate of 15% has been quoted by Collins and Chatten,4 suggesting a periodical clinical evaluation with neuroimaging studies.
19.
20. 21.
Samuel M, Moore IE, Burge DM. Thoracic wall lipoblastoma: a case report and review of histopathology and cytogenetics. Eur J Pediatr Surg 2000; 10: 53–57. Coffin CM. Lipoblastoma: an embryonal tumor of the soft tissue related to organogenesis. Semin Diag Pathol 1994; 11: 98–103. Irgau I, McNicholas KW. Mediastinal lipoblastoma involving the left innominate vein and the left phrenic nerve. J Pediatr Surg 1998; 33: 1540–1542.
CONCLUSION While the occurrence of a posterior mediastinal lipoblastoma with transintervertebral foraminal (retrograde) epidural extension and transintercostal suprascapular extension in a 2-year-old child is unique as its initial presentation as a painful suprascapular mass lesion which was initially construed as a benign lipoma. Later painful limitation of the shoulder movements with appearance of imbalance while walking prompted neurosurgical assessment with CT and MRI scans and eventual discovery and surgical excision of the tumour with no added morbidity. Such lesions are benign in their biological behaviour and commonly occur in superficial sites and rarely in deep location.5 Ideally, a complete excision is the treatment of choice with little risk of recurrence. ACKNOWLEDGEMENT We sincerely thank the Department of Neuroradiology at Khoula Hospital for the imaging studies, Professor S. K. Pandya, Senior Consultant Neurosurgeon and his cardiothoracic colleagues for the second stage of surgery.
REFERENCES 1. 2. 3. 4. 5. 6. 7. 8.
9. 10. 11.
12.
13. 14. 15. 16. 17.
18.
Joseph SG, Tellis CJ. Posterior mediastinal mass with intraspinal extension. Chest 1988; 93: 11017–1103. Quinn SF, Monson M, Paling M. Spinal lipoma presenting as a mediastinal mass. diagnoses by CT scan. J Comput Tomogr 1983; 7: 1087–1089. Kok KY, Tele Singhe PU. Lipoblastoma in a 14 year old boy. report of a case. Surg Today 1996; 26: 754–755. Collins MH, Chatten J. Lipoblastoma/lipoblastomatosis: a clinicopathological study of 25 tumors. Am J Surg Pathol 1997; 21: 1131–1137. Whyte AM, Powell N. Mediastinal lipoblastoma of infancy. Clin Radiol 1990; 42: 205–206. Federici S, Cuogni D, Sciutti R. Benign mediastinal lipoblastoma in a 14 months old infant. Pediatr Radiol 1992; 22: 150–151. KO SF, Shich CS, Shih TY et al. Mediastinal lipoblastoma with intraspinal extension. MRI demonstration. Magn Reson Imaging 1998; 16: 445–448. Duhaime AC, Chatten J, Schut L, Rorke L. Cervical lipoblastomatosis with intraspinal extension and transformation into mature fat in a child. Childs Nerv Syst 1987; 3: 304–306. Nmadu PT. Giant lipoblastoma: a case report. Ann Trop Pediatr 1992; 12: 417–419. Jimenez JF. Lipoblastoma in infancy and childhood. J Surg Oncol 1986; 12: 238–244. Arguelies-Pintos M, Martinez Gonzalez MA, Parise Methol J, Delgado Millan MA. Cervico-mediastinal lipoblastomatosis. report of a case and review of the literature. An Esp Pediatr 1991; 35: 201–203. Bertana S, Parigi GP, Giuntoli M, Pelagalli M, Battisti C, Bragheri R. Lipoblastoma and lipoblastomatosis in children. Minerva Pediatr 1999; 51: 159–166. Kamel HA, Brennan PR, Farrell MA. Cervical epidural lipoblastomatosis: changing MR appearance after chemotherapy. AJNR 1999; 20: 386–389. Marques Gubera A, Jimenez AI, Martinez Libanez V et al. Embryonal fatty tumors. lipoblastomas, lipoblastomatosis. Cir Pediatr 1990; 3: 109–112. Farrugia MK, Fearne C. Benign lipoblastoma arising in the neck. Pediatr Surg Int 1998; 13; 213–214. Stringel G, Shandling B, Mancer K, Ein SH. Lipoblastoma in infants and children. J Pediatr Surg 1982; 17: 277–280. Ricci C, Redina EA, Venuta F, Pescarmona EO, Gagliardi F. Diagnostic imaging and surgical treatment of dumbbell tumors of the mediastinum. Ann Thoracic Surg 1990; 50: 586–589. Schistad O, Loe B, Vidaal KO, Naess PA, Roald B, Reiseter T, Borhno C. Lipoblastoma. A rare, benign tumor in children. Tidsskar Nor Laegeforen 1997; 117: 3497–3498.
© 2002, Elsevier Science Ltd. All rights reserved.
Aneurysm of the anterior inferior cerebellar artery (AICA) associated with high-flow lesion: report of two cases and review of literature Tomas Menovsky MD PHD, J. André Grotenhuis MD PHD, Ronald H.M.A. Bartels MD Department of Neurosurgery, University Hospital Nijmegen St Radboud, PO Box 9109, 6500 HB Nijmegen, The Netherlands
Summary Objective and importance: Although aneurysms of the anterior inferior cerebellar artery (AICA) are rare lesions, their occurrence in combination with high-flow lesions in the same arterial territory is even more striking. Two cases of an AICA aneurysm in combination with a high-flow lesion are described. Clinical presentation: In one case, a 52-year-old female presented with cerebellar syndrome as the result of a left-sided cerebellar tumor. Angiography revealed a highly vascularized tumor and a broad-based aneurysm at the offspring of the left AICA. In the second case, a 17year-old female presented with a right-sided cerebellar hemorrhage. Angiography revealed a large peripheral AICA aneurysm and a distal arteriovenous malformation (AVM) fed by the AICA. Intervention: In the first case, a left lateral suboccipital craniotomy was performed and a highly vascularized tumor was removed. The AICA aneurysm could not be adequately clipped and was subsequently wrapped with muscle and reinforced with fibrin glue. Pathological examination of the tumor revealed a hemangioblastoma. Five years after surgery, the patient experienced a subarachnoid hemorrhage. Subsequent vertebral angiography revealed local enlargement of the known AICA aneurysm just at the superior aspect, but the patient refused further treatment. In the second case, the patient sustained a novel cerebellar rebleed while awaiting surgery. A right-sided lateral retromastoid suboccipital craniotomy was performed and the AICA aneurysm could be successfully clipped. More peripherally, the AVM with two draining veins could be totally removed. Postoperative angiography revealed no residual aneurysm or AVM. Conclusion: Several aspects of these cases are discussed, such as the rare occurrence of AICA aneurysm and the contribution of high-flow lesions to the genesis of the AICA aneurysms. © 2002, Elsevier Science Ltd. All rights reserved. Journal of Clinical Neuroscience (2002) 9(2), 207–211 © 2002, Elsevier Science Ltd. All rights reserved. DOI: 10.1054/jocn.2001.0945; available online at http://www.idealibrary.com on
Keywords: aneurysm, anterior inferior cerebellar artery, arteriovenous malformation, hemangioblastoma, tumor
Journal of Clinical Neuroscience (2002) 9(2)
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Received 18 February 2000 Accepted 25 April 2001 Correspondence to: Dr Tomas Menovsky MD, PhD. Tel.: +31 24 361 3477; Fax: +31 24 354 1587; E-mail: [email protected]
INTRODUCTION Although aneurysms of the posterior circulation represent about 10–15% of all intracranial aneurysm in cases with subarachnoid hemorrhage, aneurysms of the anterior inferior cerebellar artery (AICA) are relatively rare with an incidence of about 1–2%.1 It is a well-known phenomenon that increased hemodynamic stress exerted upon an artery is a significant contributing factor for aneurysmal initiation. For example, association of an aneurysm with an arteriovenous malformations (AVM) occurs in 5–10% of all AVM patients.2,4 Association of a brain tumor with an intracranial aneurysm is an extraordinary event. Most patients harbor supratentorial meningiomas or pituitary adenomas. Only a few cases of a posterior fossa tumor associated with an intracranial aneurysm have been described.5–7 However, only one of these cases with an infratentorial tumor suffered from a AICA aneurysm.8 In this report, we describe two patients with an extremely rare combination of an AICA aneurysm with an AVM and a hemangioblastoma respectively.
A
CASE REPORTS Case 1 This 52-year-old Caucasian female complained of cervical pain and discomfort for about 18 months, associated with gait disturbances, loss of balance and episodes of diminished visual acuity during the last few months. The pain became worse and appeared in attacks, accompanied by dizziness and vomiting, resulting in admission to the neurological department. The neurological examination did not reveal papilledema or other clinical signs of raised intracranial pressure. Left cerebellar symptoms were found, as was hyperreflexia on the right side. Computed-assisted tomography (CT) (Fig. 1) showed a large space-occupying lesion in the left cerebellar hemisphere with a diameter of 5 cm with huge perifocal edema and obstructive hydrocephalus. Vertebral angiography showed excessive vascularization of the tumor (Fig. 2A) and a broad-based aneurysm of the AICA at the offspring of the basilar artery (Fig. 2B). The patient was then referred to our department for surgical treatment. Through a left lateral suboccipital craniotomy, a highly vascularized tumor was removed, which appeared to be mostly solid. After total removal of the tumor, the AICA aneurysm was approached along the cerebellopontine angle, superior and inferior of the acoustic–facial bundle. The aneurysm had a broad neck and the first applied clip slipped off the aneurysm. A second clip was applied but this led to strangulation of the basilar artery. After several unsuccessful attempts to clip the neck, the aneurysm was wrapped with muscle and reinforced with fibrin glue. This wrapping was difficult at the most distant part of the aneurysm, since this could not be visualized adequately. Pathological examination of the lesion revealed a hemangioblastoma. Postoperative course was uneventful and eight days later the patient was discharged in good condition. During the 4-year follow-up, the patient led a normal life without any neurological deficit and no signs of tumor recurrence or subarachnoid hemorrhage. Five years after surgery, however, the patient experienced a sudden severe headache, but she did not seek medical attention. Two weeks later, she was admitted to our department with an Journal of Clinical Neuroscience (2002) 9(2)
B Fig. 1(A,B) Preoperative CT scanning (with contrast) showing a large space-occupying lesion in the left cerebellar hemisphere with enhancement and a small peripheral nidus.
another attack of severe headache. She was found unconscious with pronounced neck stiffness but without any other neurological deficit. CT-scanning revealed subarachnoid hemorrhage and subsequent vertebral angiography revealed local enlargement of the known AICA aneurysm just at the superior aspect (Fig. 3) which apparently had bled. Both CT and angiography showed no signs of tumor recurrence. She made an uneventful recovery but she refused surgery as well as endovascular coiling of the aneurysm because of the possible risks of the proposed interventions. Until now, seven years after the bleeding, she is still doing well.
Case 2 This 17-year-old white female was admitted because of sudden headache followed by loss of consciousness. Neurological © 2002, Elsevier Science Ltd. All rights reserved.
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A
Fig. 3 Vertebral angiography five years after wrapping showing the known aneurysm of the AICA with a newly developed local enlargement at the superior aspect of the aneurysm.
B Fig. 2 Vertebral angiography showed excessive vascularization of the tumor (A) and a left sided broad-based aneurysm of the AICA at the junction of the basilar artery (B).
examination revealed impaired consciousness with localizing reactions to pain, but no verbal reaction or eye opening, neck stiffness, and signs of raised intracranial pressure. CT-scanning showed a cerebellar hemorrhage (Fig. 4A) with extension into the fourth, third, and lateral ventricles with acute obstructive supratentorial hydrocephalus. An emergency external ventricular drain (EVD) was inserted. The cerebrospinal fluid was reddish and had © 2002, Elsevier Science Ltd. All rights reserved.
a pressure of^30 cm H2O. In the following days, the patient gradually regained consciousness and within one week, she was fully conscious without neurological deficits. The EVD was subsequently removed. An angiography was performed and revealed a 2 cm large aneurysm of the distal right AICA and distally from the aneurysm an AVM with a size of 2.5 cm (Fig. 4B). Surgical clipping of the aneurysm and removal of the AVM were scheduled, but over the weekend, 14 days after the initial hemorrhage, she sustained a novel cerebellar hemorrhage (Fig. 5A) with perforation into the fourth, third, and lateral ventricles. Again, an emergency EVD was placed, followed by immediate right-sided lateral retromastoid suboccipital craniotomy. After evacuation of a large cerebellar hematoma, the AICA was followed to the periphery until an aneurysm could be observed. Although the aneurysm was large, it had a very small neck which could be clipped with a small straight aneurysm clip. Subsequently, the aneurysm was opened and the thrombus was removed. Peripheral to the clipped aneurysm, an AVM was present with two draining veins that could be totally removed. Postoperative course was uneventful and four weeks later the patient was discharged in good clinical condition. Postoperative angiography showed no residual AVM or AICA aneurysm (Fig. 5B). Until now, three years later, she is doing very well without any neurological deficit. DISCUSSION Aneurysms of the anterior inferior cerebellar artery are relatively rare and only approximately 60 cases of surgically treated AICA aneurysms have been reported.9 AICA aneurysms occur predominantly in women and the majority of AICA aneurysms are located in the vicinity of the internal auditory canal.9,10 Those affecting the proximal part of the AICA are very rare and most of the cases have been described as case reports. Most of the AICA aneurysms present themselves as a cerebellopontine mass or, less frequently, give rise to a subarachnoid hemorrhage.9 Facial nerve paresis and hearing disturbances may occur during the clinical course. As a Journal of Clinical Neuroscience (2002) 9(2)
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A
A
B Fig. 5 (A) CT-scanning demonstrating a novel cerebellar hemorrhage. (B) Postoperative angiography of the posterior circulation showing no residual AICA aneurysm or AVM.
B Fig. 4 (A) CT-scanning demonstrating a cerebellar hemorrhage. (B) Angiography of the posterior circulation showing a large AICA aneurysm and a peripheral AVM fed by the AICA.
consequence, a SAH in combination with symptoms of the seventh and/or eight cranial nerve is very suggestive of a ruptured distal AICA aneurysm.10 The cause of cranial nerve dysfunction can be ischemic, by direct compression, or the presence of hemosiderin within the inner ear after SAH. For some aneurysms, the origin of their existence is known, e.g. post-traumatic or mycotic aneurysms. However, the genesis of most aneurysms is still unclear, although a congenital predisposition and/or hemodynamic stress, for example caused by hypertension, to a weakened part of the blood vessel contributes to the Journal of Clinical Neuroscience (2002) 9(2)
formation of an aneurysm.11 Increased blood flow through a blood vessel also causes hemodynamic stress to the wall of the vessel. Both an AVM and a hemangioblastoma have a common factor, i.e. the augmented blood flow towards the lesion. The etiology of cerebral aneurysm and an AVM in the same patient are still not fully elucidated. The aneurysms can be divided into four types: (1) unrelated dysplastic or incidental aneurysms (hemodynamically independent); (2) flow-related on proximal feeding vessels; (3) flow-related on distal small feeding vessels; and (4) intranidal aneurysms associated with the AVM.2,3,12 Congenital disorders of cerebral vessels may explain the first type of aneurysms which are hemodynamically independent of the AVM. The occurrence of an intracranial saccular aneurysm of the feeding artery to an AVM (flow-related aneurysm) is a well-known phenomenon.2,3,13 The increase in the blood flow in a vessel feeding an AVM predisposes the development of an aneurysm on that feeding vessel. This is supported by reports of spontaneous disappearance of aneurysms after the AVM has been taken out from the cerebral circulation.2,3 It has been shown that pedicle aneurysms on feeding vessels occur more frequently in conjunction with © 2002, Elsevier Science Ltd. All rights reserved.
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infratentorial AVMs.12 Moreover, such aneurysms are frequently associated with hemorrhage which carries extra risk to the patient. The coincidence of these vascular disorders within the posterior fossa is still very uncommon. In the literature, the incidence of cerebral aneurysm in combination with an AVM is reported to be around 1.4–8.7%. The association of an AICA aneurysm with an AVM on the same feeding artery has been described only in six other cases.8,14–17 A strong argument in favor of a causal relationship between the AICA aneurysm and the AVM is the location of the AICA aneurysms in our cases. Whereas most AICA aneurysms are located more peripherally, which has been similarly reported in other cases with an AVM and a coexisting aneurysm, the aneurysm in case 1 was situated at the junction between the basilar artery and the AICA. This further supports the concept that these aneurysms are flow-related and are not caused by a generalized vascular pathological entity. Surgical treatment should be directed towards the malformation responsible for bleeding or symptoms and also for the ‘asymptomatic’ malformation. Treatment of aneurysm alone or AVM alone may lead to an increased risk of bleeding from the remaining lesion because of the altered hemodynamic situation. To date, only three cases of a coexisting aneurysm and cerebellar hemangioblastoma have been described in the literature and only one paper describes an AICA aneurysm located on the main feeding artery of the tumor.8 Hemangioblastomas have an incidence of 1–2% of all intracranial tumors and 7–12% of all tumors in the fossa posterior. The predilection site of origin is the cerebellum. In 25% of cases, a hemangioblastoma is a manifestation of the hereditary von Hippel-Lindau disease.18 Histologically, hemangioblastomas are characterized by a dense capillary network.19 The capillary network consists of vascular endothelial cells which express vascular endothelial growth factor (VEGF), also known as vascular permeability factor.20 VEGF is a strong regulator of blood vessel function acting on endothelial cells and endothelium. It promotes hyperpermeability, endothelium growth, and angiogenesis.21 It has been shown that increased hemodynamic stress on the vessel wall such as occurs in aneurysms and AVMs leads to increase of expression of VEGF.22 Analog to the AVM, the arteries that feed the hemangioblastoma have an augmeted flow (high-flow feeders) due to the lack of capillary resistance within the hemangioblastoma. In this context, the coexistence of a hemangioblastoma and an aneurysm on the feeding artery may be thus at least partly of multifactorial origin. In conclusion, two cases with an AICA aneurysm and a concomitant lesion (an AVM and a hemangioblastoma) are reported. Both lesions are highly vascular resulting in an increased blood flow through the feeding artery (AICA). Therefore, it seems logical to assume a causal relationship between the presence of these highly vascularized lesions and the AICA aneurysms.
REFERENCES 1. Johnson JJ, Kline DG. Anterior inferior cerebellar artery aneurysms. case report. J Neurosurg 1978; 48: 455–460. 2. Thompson RC, Steinberg GK, Levy RP, Marks MP. The management of patients with arteriovenous malformations and associated intracranial aneurysms. Neurosurgery 1998; 43: 202–211. 3. Redekop G, TerBrugge K, Montanera W, Willinsky R. Arterial aneurysms associated with cerebral arteriovenous malformations: classification, incidence, and risk of hemorrhage. J Neurosurg 1998; 89: 539–546. 4 Cockroft KM, Thompson RC, Steinberg GK. Aneurysms and arteriovenous malformations. Neurosurg Clin N Am 1998; 9: 565–76. 5. Wakai S, Fukushima T, Furihata T. Association of cerebral aneurysm with pituitary adenoma. Surg Neurol 1979; 12: 503–507. 6. Jakubowski J, Kendall B. Coincidental aneurysms with tumours of pituitary origin. J Neurol Neurosurg Psychiatr 1978; 41: 972–979.
© 2002, Elsevier Science Ltd. All rights reserved.
7. 8. 9.
10.
11. 12.
13.
14. 15.
16.
17. 18.
19. 20. 21.
22.
Pia HW, Obrador S, Martin JG. Association of brain tumours and arterial intracranial aneurysms. Acta Neurochir 1972; 27: 189–204. Guzman R, Grady MS. An intracranial aneurysm on the feeding artery of a cerebellar hemangioblastoma. J Neurosurg 1999; 91: 136–138. Mizushima H, Kobayashi N, Yoshiharu S et al. Aneurysm of the distal anterior inferior cerebellar artery at the medial branch: a case report and review of the literature. Surg Neurol 1999; 52: 137–142. Dalley RW, Robertson WD, Nugent RA, Durity FA. Computed tomography of anterior inferior cerebellar artery aneurysm mimicking an acoustic neuroma. J Comput Assist Tomogr 1986; 10: 881–884. Fry DL. Acute vascular endothelial changes associated with increased blood velocity gradients. Circ Res 1968; 22: 165–197. Westphal M, Grzyska U. Clinical significance of pedicle aneurysms on feeding vessels, especially those located in infratentorial arteriovenous malformations. J Neurosurg 2000; 92: 995–1001. Okamoto S, Handa H, Hashimoto H. Location of intracranial aneurysms associated with cerebral arteriovenous malformation: statistical analysis. Surg Neurol 1984; 22: 335–340. Tarlov E. Subarachnoid hemorrhage. Prim Care 1979; 6: 791–803. Nishi S, Taki W, Nakahara I et al. Embolization of cerebral aneurysms with a liquid embolus, EVAL mixture: report of three cases. Acta Neurochir Wien 1996; 138: 294–300. Vincentelli F, Caruso G, Licastro G, Rabehanta P. Association between an aneurysm of the anterior inferior cerebral artery and an arteriovenous malformation fed by the same artery. J Neurosurg Sci 1998; 42: 41–45. Gacs G, Vinuela F, Fox AJ, Drake CG. Peripheral aneurysms of the cerebellar arteries. review of 16 cases. J Neurosurg 1983; 58: 63–68. Neumann HPH, Eggert HR, Weigel K, Friedbug H, Wiestler O, Schollmeyer P. Hemangioblastomas of the central nervous system. a 10-year study with special reference to von Hippel–Lindau disease. J Neurosurg 1989; 70: 24–30. Wizigmann-Voos S, Plate KH. Pathology, genetics and cell biology of hemangioblastomas. Histol Histopathol 1996; 11: 1049–1061. de Vries C, Escobedo JA, Ueno H. The fsm-like tyrosine kinase, a receptor for vascular endothelial growth factor. Science 1992; 255: 989–991. Wizigmann-Voos S, Breier G, Risau W. Up-regulation of vascular endothelial growth factor and its receptors in von Hippel–Lindau disease-associated and sporadic hemangioblastomas. Cancer Res 1995; 55: 1358–1364. Schwartz SM, Liaw L. Growth control and morphogenesis in the development and pathology of arteries. J Cardiovasc Pharmacol 1993; 21(Suppl 1): 31–49.
Malignant astrocytoma of the conus medullaris treated by spinal cordectomy Kazuhiko Kyoshima MD, Kiyoshi Ito MD, Akihiko Tanabe MD, Tomomi Iwashita MD, Tetsuya Goto MD, Atsushi Sato MD, Jun Nakayama1 MD Departments of Neurosurgery and 1Laboratory Medicine, Shinshu University School of Medicine, Matsumoto, Japan
Summary We present a case of malignant astrocytoma of the conus medullaris in a 48-year-old man treated by spinal cordectomy. Preoperative examination revealed a tumor at the T12 to L1 level, and intraparenchymal invasion up to T8. The spinal cord was amputated caudally to the root entry zones of the T9 sensory roots. Additional cordectomies were repeated three times because of tumor infiltration at the cut end. At each procedure, the cord was segmentally transected just caudal to the root entry zones of the preserving-aid sensory roots to minimize the neural deficit. The final transected level was between T3 and T4, and the cut end did not pathologically reveal any tumor invasion. However, the patient died from tumor recurrence and dissemination. Although the attempt to control the tumor by long segment cordectomy was unsuccessful, spinal cordectomy with wide margin may be a possible treatment for
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was completely excised in two stages. A complete resection of a lipoblastoma is feasible and advantageous with no need for a mutilating radical excision. A recurrence rate of 15% has been quoted by Collins and Chatten,4 suggesting a periodical clinical evaluation with neuroimaging studies.
19.
20. 21.
Samuel M, Moore IE, Burge DM. Thoracic wall lipoblastoma: a case report and review of histopathology and cytogenetics. Eur J Pediatr Surg 2000; 10: 53–57. Coffin CM. Lipoblastoma: an embryonal tumor of the soft tissue related to organogenesis. Semin Diag Pathol 1994; 11: 98–103. Irgau I, McNicholas KW. Mediastinal lipoblastoma involving the left innominate vein and the left phrenic nerve. J Pediatr Surg 1998; 33: 1540–1542.
CONCLUSION While the occurrence of a posterior mediastinal lipoblastoma with transintervertebral foraminal (retrograde) epidural extension and transintercostal suprascapular extension in a 2-year-old child is unique as its initial presentation as a painful suprascapular mass lesion which was initially construed as a benign lipoma. Later painful limitation of the shoulder movements with appearance of imbalance while walking prompted neurosurgical assessment with CT and MRI scans and eventual discovery and surgical excision of the tumour with no added morbidity. Such lesions are benign in their biological behaviour and commonly occur in superficial sites and rarely in deep location.5 Ideally, a complete excision is the treatment of choice with little risk of recurrence. ACKNOWLEDGEMENT We sincerely thank the Department of Neuroradiology at Khoula Hospital for the imaging studies, Professor S. K. Pandya, Senior Consultant Neurosurgeon and his cardiothoracic colleagues for the second stage of surgery.
REFERENCES 1. 2. 3. 4. 5. 6. 7. 8.
9. 10. 11.
12.
13. 14. 15. 16. 17.
18.
Joseph SG, Tellis CJ. Posterior mediastinal mass with intraspinal extension. Chest 1988; 93: 11017–1103. Quinn SF, Monson M, Paling M. Spinal lipoma presenting as a mediastinal mass. diagnoses by CT scan. J Comput Tomogr 1983; 7: 1087–1089. Kok KY, Tele Singhe PU. Lipoblastoma in a 14 year old boy. report of a case. Surg Today 1996; 26: 754–755. Collins MH, Chatten J. Lipoblastoma/lipoblastomatosis: a clinicopathological study of 25 tumors. Am J Surg Pathol 1997; 21: 1131–1137. Whyte AM, Powell N. Mediastinal lipoblastoma of infancy. Clin Radiol 1990; 42: 205–206. Federici S, Cuogni D, Sciutti R. Benign mediastinal lipoblastoma in a 14 months old infant. Pediatr Radiol 1992; 22: 150–151. KO SF, Shich CS, Shih TY et al. Mediastinal lipoblastoma with intraspinal extension. MRI demonstration. Magn Reson Imaging 1998; 16: 445–448. Duhaime AC, Chatten J, Schut L, Rorke L. Cervical lipoblastomatosis with intraspinal extension and transformation into mature fat in a child. Childs Nerv Syst 1987; 3: 304–306. Nmadu PT. Giant lipoblastoma: a case report. Ann Trop Pediatr 1992; 12: 417–419. Jimenez JF. Lipoblastoma in infancy and childhood. J Surg Oncol 1986; 12: 238–244. Arguelies-Pintos M, Martinez Gonzalez MA, Parise Methol J, Delgado Millan MA. Cervico-mediastinal lipoblastomatosis. report of a case and review of the literature. An Esp Pediatr 1991; 35: 201–203. Bertana S, Parigi GP, Giuntoli M, Pelagalli M, Battisti C, Bragheri R. Lipoblastoma and lipoblastomatosis in children. Minerva Pediatr 1999; 51: 159–166. Kamel HA, Brennan PR, Farrell MA. Cervical epidural lipoblastomatosis: changing MR appearance after chemotherapy. AJNR 1999; 20: 386–389. Marques Gubera A, Jimenez AI, Martinez Libanez V et al. Embryonal fatty tumors. lipoblastomas, lipoblastomatosis. Cir Pediatr 1990; 3: 109–112. Farrugia MK, Fearne C. Benign lipoblastoma arising in the neck. Pediatr Surg Int 1998; 13; 213–214. Stringel G, Shandling B, Mancer K, Ein SH. Lipoblastoma in infants and children. J Pediatr Surg 1982; 17: 277–280. Ricci C, Redina EA, Venuta F, Pescarmona EO, Gagliardi F. Diagnostic imaging and surgical treatment of dumbbell tumors of the mediastinum. Ann Thoracic Surg 1990; 50: 586–589. Schistad O, Loe B, Vidaal KO, Naess PA, Roald B, Reiseter T, Borhno C. Lipoblastoma. A rare, benign tumor in children. Tidsskar Nor Laegeforen 1997; 117: 3497–3498.
© 2002, Elsevier Science Ltd. All rights reserved.
Aneurysm of the anterior inferior cerebellar artery (AICA) associated with high-flow lesion: report of two cases and review of literature Tomas Menovsky MD PHD, J. André Grotenhuis MD PHD, Ronald H.M.A. Bartels MD Department of Neurosurgery, University Hospital Nijmegen St Radboud, PO Box 9109, 6500 HB Nijmegen, The Netherlands
Summary Objective and importance: Although aneurysms of the anterior inferior cerebellar artery (AICA) are rare lesions, their occurrence in combination with high-flow lesions in the same arterial territory is even more striking. Two cases of an AICA aneurysm in combination with a high-flow lesion are described. Clinical presentation: In one case, a 52-year-old female presented with cerebellar syndrome as the result of a left-sided cerebellar tumor. Angiography revealed a highly vascularized tumor and a broad-based aneurysm at the offspring of the left AICA. In the second case, a 17year-old female presented with a right-sided cerebellar hemorrhage. Angiography revealed a large peripheral AICA aneurysm and a distal arteriovenous malformation (AVM) fed by the AICA. Intervention: In the first case, a left lateral suboccipital craniotomy was performed and a highly vascularized tumor was removed. The AICA aneurysm could not be adequately clipped and was subsequently wrapped with muscle and reinforced with fibrin glue. Pathological examination of the tumor revealed a hemangioblastoma. Five years after surgery, the patient experienced a subarachnoid hemorrhage. Subsequent vertebral angiography revealed local enlargement of the known AICA aneurysm just at the superior aspect, but the patient refused further treatment. In the second case, the patient sustained a novel cerebellar rebleed while awaiting surgery. A right-sided lateral retromastoid suboccipital craniotomy was performed and the AICA aneurysm could be successfully clipped. More peripherally, the AVM with two draining veins could be totally removed. Postoperative angiography revealed no residual aneurysm or AVM. Conclusion: Several aspects of these cases are discussed, such as the rare occurrence of AICA aneurysm and the contribution of high-flow lesions to the genesis of the AICA aneurysms. © 2002, Elsevier Science Ltd. All rights reserved. Journal of Clinical Neuroscience (2002) 9(2), 207–211 © 2002, Elsevier Science Ltd. All rights reserved. DOI: 10.1054/jocn.2001.0945; available online at http://www.idealibrary.com on
Keywords: aneurysm, anterior inferior cerebellar artery, arteriovenous malformation, hemangioblastoma, tumor
Journal of Clinical Neuroscience (2002) 9(2)
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3/18/02 1:20 PM
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208 Menovsky et al.
Received 18 February 2000 Accepted 25 April 2001 Correspondence to: Dr Tomas Menovsky MD, PhD. Tel.: +31 24 361 3477; Fax: +31 24 354 1587; E-mail: [email protected]
INTRODUCTION Although aneurysms of the posterior circulation represent about 10–15% of all intracranial aneurysm in cases with subarachnoid hemorrhage, aneurysms of the anterior inferior cerebellar artery (AICA) are relatively rare with an incidence of about 1–2%.1 It is a well-known phenomenon that increased hemodynamic stress exerted upon an artery is a significant contributing factor for aneurysmal initiation. For example, association of an aneurysm with an arteriovenous malformations (AVM) occurs in 5–10% of all AVM patients.2,4 Association of a brain tumor with an intracranial aneurysm is an extraordinary event. Most patients harbor supratentorial meningiomas or pituitary adenomas. Only a few cases of a posterior fossa tumor associated with an intracranial aneurysm have been described.5–7 However, only one of these cases with an infratentorial tumor suffered from a AICA aneurysm.8 In this report, we describe two patients with an extremely rare combination of an AICA aneurysm with an AVM and a hemangioblastoma respectively.
A
CASE REPORTS Case 1 This 52-year-old Caucasian female complained of cervical pain and discomfort for about 18 months, associated with gait disturbances, loss of balance and episodes of diminished visual acuity during the last few months. The pain became worse and appeared in attacks, accompanied by dizziness and vomiting, resulting in admission to the neurological department. The neurological examination did not reveal papilledema or other clinical signs of raised intracranial pressure. Left cerebellar symptoms were found, as was hyperreflexia on the right side. Computed-assisted tomography (CT) (Fig. 1) showed a large space-occupying lesion in the left cerebellar hemisphere with a diameter of 5 cm with huge perifocal edema and obstructive hydrocephalus. Vertebral angiography showed excessive vascularization of the tumor (Fig. 2A) and a broad-based aneurysm of the AICA at the offspring of the basilar artery (Fig. 2B). The patient was then referred to our department for surgical treatment. Through a left lateral suboccipital craniotomy, a highly vascularized tumor was removed, which appeared to be mostly solid. After total removal of the tumor, the AICA aneurysm was approached along the cerebellopontine angle, superior and inferior of the acoustic–facial bundle. The aneurysm had a broad neck and the first applied clip slipped off the aneurysm. A second clip was applied but this led to strangulation of the basilar artery. After several unsuccessful attempts to clip the neck, the aneurysm was wrapped with muscle and reinforced with fibrin glue. This wrapping was difficult at the most distant part of the aneurysm, since this could not be visualized adequately. Pathological examination of the lesion revealed a hemangioblastoma. Postoperative course was uneventful and eight days later the patient was discharged in good condition. During the 4-year follow-up, the patient led a normal life without any neurological deficit and no signs of tumor recurrence or subarachnoid hemorrhage. Five years after surgery, however, the patient experienced a sudden severe headache, but she did not seek medical attention. Two weeks later, she was admitted to our department with an Journal of Clinical Neuroscience (2002) 9(2)
B Fig. 1(A,B) Preoperative CT scanning (with contrast) showing a large space-occupying lesion in the left cerebellar hemisphere with enhancement and a small peripheral nidus.
another attack of severe headache. She was found unconscious with pronounced neck stiffness but without any other neurological deficit. CT-scanning revealed subarachnoid hemorrhage and subsequent vertebral angiography revealed local enlargement of the known AICA aneurysm just at the superior aspect (Fig. 3) which apparently had bled. Both CT and angiography showed no signs of tumor recurrence. She made an uneventful recovery but she refused surgery as well as endovascular coiling of the aneurysm because of the possible risks of the proposed interventions. Until now, seven years after the bleeding, she is still doing well.
Case 2 This 17-year-old white female was admitted because of sudden headache followed by loss of consciousness. Neurological © 2002, Elsevier Science Ltd. All rights reserved.
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Fig. 3 Vertebral angiography five years after wrapping showing the known aneurysm of the AICA with a newly developed local enlargement at the superior aspect of the aneurysm.
B Fig. 2 Vertebral angiography showed excessive vascularization of the tumor (A) and a left sided broad-based aneurysm of the AICA at the junction of the basilar artery (B).
examination revealed impaired consciousness with localizing reactions to pain, but no verbal reaction or eye opening, neck stiffness, and signs of raised intracranial pressure. CT-scanning showed a cerebellar hemorrhage (Fig. 4A) with extension into the fourth, third, and lateral ventricles with acute obstructive supratentorial hydrocephalus. An emergency external ventricular drain (EVD) was inserted. The cerebrospinal fluid was reddish and had © 2002, Elsevier Science Ltd. All rights reserved.
a pressure of^30 cm H2O. In the following days, the patient gradually regained consciousness and within one week, she was fully conscious without neurological deficits. The EVD was subsequently removed. An angiography was performed and revealed a 2 cm large aneurysm of the distal right AICA and distally from the aneurysm an AVM with a size of 2.5 cm (Fig. 4B). Surgical clipping of the aneurysm and removal of the AVM were scheduled, but over the weekend, 14 days after the initial hemorrhage, she sustained a novel cerebellar hemorrhage (Fig. 5A) with perforation into the fourth, third, and lateral ventricles. Again, an emergency EVD was placed, followed by immediate right-sided lateral retromastoid suboccipital craniotomy. After evacuation of a large cerebellar hematoma, the AICA was followed to the periphery until an aneurysm could be observed. Although the aneurysm was large, it had a very small neck which could be clipped with a small straight aneurysm clip. Subsequently, the aneurysm was opened and the thrombus was removed. Peripheral to the clipped aneurysm, an AVM was present with two draining veins that could be totally removed. Postoperative course was uneventful and four weeks later the patient was discharged in good clinical condition. Postoperative angiography showed no residual AVM or AICA aneurysm (Fig. 5B). Until now, three years later, she is doing very well without any neurological deficit. DISCUSSION Aneurysms of the anterior inferior cerebellar artery are relatively rare and only approximately 60 cases of surgically treated AICA aneurysms have been reported.9 AICA aneurysms occur predominantly in women and the majority of AICA aneurysms are located in the vicinity of the internal auditory canal.9,10 Those affecting the proximal part of the AICA are very rare and most of the cases have been described as case reports. Most of the AICA aneurysms present themselves as a cerebellopontine mass or, less frequently, give rise to a subarachnoid hemorrhage.9 Facial nerve paresis and hearing disturbances may occur during the clinical course. As a Journal of Clinical Neuroscience (2002) 9(2)
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B Fig. 5 (A) CT-scanning demonstrating a novel cerebellar hemorrhage. (B) Postoperative angiography of the posterior circulation showing no residual AICA aneurysm or AVM.
B Fig. 4 (A) CT-scanning demonstrating a cerebellar hemorrhage. (B) Angiography of the posterior circulation showing a large AICA aneurysm and a peripheral AVM fed by the AICA.
consequence, a SAH in combination with symptoms of the seventh and/or eight cranial nerve is very suggestive of a ruptured distal AICA aneurysm.10 The cause of cranial nerve dysfunction can be ischemic, by direct compression, or the presence of hemosiderin within the inner ear after SAH. For some aneurysms, the origin of their existence is known, e.g. post-traumatic or mycotic aneurysms. However, the genesis of most aneurysms is still unclear, although a congenital predisposition and/or hemodynamic stress, for example caused by hypertension, to a weakened part of the blood vessel contributes to the Journal of Clinical Neuroscience (2002) 9(2)
formation of an aneurysm.11 Increased blood flow through a blood vessel also causes hemodynamic stress to the wall of the vessel. Both an AVM and a hemangioblastoma have a common factor, i.e. the augmented blood flow towards the lesion. The etiology of cerebral aneurysm and an AVM in the same patient are still not fully elucidated. The aneurysms can be divided into four types: (1) unrelated dysplastic or incidental aneurysms (hemodynamically independent); (2) flow-related on proximal feeding vessels; (3) flow-related on distal small feeding vessels; and (4) intranidal aneurysms associated with the AVM.2,3,12 Congenital disorders of cerebral vessels may explain the first type of aneurysms which are hemodynamically independent of the AVM. The occurrence of an intracranial saccular aneurysm of the feeding artery to an AVM (flow-related aneurysm) is a well-known phenomenon.2,3,13 The increase in the blood flow in a vessel feeding an AVM predisposes the development of an aneurysm on that feeding vessel. This is supported by reports of spontaneous disappearance of aneurysms after the AVM has been taken out from the cerebral circulation.2,3 It has been shown that pedicle aneurysms on feeding vessels occur more frequently in conjunction with © 2002, Elsevier Science Ltd. All rights reserved.
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infratentorial AVMs.12 Moreover, such aneurysms are frequently associated with hemorrhage which carries extra risk to the patient. The coincidence of these vascular disorders within the posterior fossa is still very uncommon. In the literature, the incidence of cerebral aneurysm in combination with an AVM is reported to be around 1.4–8.7%. The association of an AICA aneurysm with an AVM on the same feeding artery has been described only in six other cases.8,14–17 A strong argument in favor of a causal relationship between the AICA aneurysm and the AVM is the location of the AICA aneurysms in our cases. Whereas most AICA aneurysms are located more peripherally, which has been similarly reported in other cases with an AVM and a coexisting aneurysm, the aneurysm in case 1 was situated at the junction between the basilar artery and the AICA. This further supports the concept that these aneurysms are flow-related and are not caused by a generalized vascular pathological entity. Surgical treatment should be directed towards the malformation responsible for bleeding or symptoms and also for the ‘asymptomatic’ malformation. Treatment of aneurysm alone or AVM alone may lead to an increased risk of bleeding from the remaining lesion because of the altered hemodynamic situation. To date, only three cases of a coexisting aneurysm and cerebellar hemangioblastoma have been described in the literature and only one paper describes an AICA aneurysm located on the main feeding artery of the tumor.8 Hemangioblastomas have an incidence of 1–2% of all intracranial tumors and 7–12% of all tumors in the fossa posterior. The predilection site of origin is the cerebellum. In 25% of cases, a hemangioblastoma is a manifestation of the hereditary von Hippel-Lindau disease.18 Histologically, hemangioblastomas are characterized by a dense capillary network.19 The capillary network consists of vascular endothelial cells which express vascular endothelial growth factor (VEGF), also known as vascular permeability factor.20 VEGF is a strong regulator of blood vessel function acting on endothelial cells and endothelium. It promotes hyperpermeability, endothelium growth, and angiogenesis.21 It has been shown that increased hemodynamic stress on the vessel wall such as occurs in aneurysms and AVMs leads to increase of expression of VEGF.22 Analog to the AVM, the arteries that feed the hemangioblastoma have an augmeted flow (high-flow feeders) due to the lack of capillary resistance within the hemangioblastoma. In this context, the coexistence of a hemangioblastoma and an aneurysm on the feeding artery may be thus at least partly of multifactorial origin. In conclusion, two cases with an AICA aneurysm and a concomitant lesion (an AVM and a hemangioblastoma) are reported. Both lesions are highly vascular resulting in an increased blood flow through the feeding artery (AICA). Therefore, it seems logical to assume a causal relationship between the presence of these highly vascularized lesions and the AICA aneurysms.
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Malignant astrocytoma of the conus medullaris treated by spinal cordectomy Kazuhiko Kyoshima MD, Kiyoshi Ito MD, Akihiko Tanabe MD, Tomomi Iwashita MD, Tetsuya Goto MD, Atsushi Sato MD, Jun Nakayama1 MD Departments of Neurosurgery and 1Laboratory Medicine, Shinshu University School of Medicine, Matsumoto, Japan
Summary We present a case of malignant astrocytoma of the conus medullaris in a 48-year-old man treated by spinal cordectomy. Preoperative examination revealed a tumor at the T12 to L1 level, and intraparenchymal invasion up to T8. The spinal cord was amputated caudally to the root entry zones of the T9 sensory roots. Additional cordectomies were repeated three times because of tumor infiltration at the cut end. At each procedure, the cord was segmentally transected just caudal to the root entry zones of the preserving-aid sensory roots to minimize the neural deficit. The final transected level was between T3 and T4, and the cut end did not pathologically reveal any tumor invasion. However, the patient died from tumor recurrence and dissemination. Although the attempt to control the tumor by long segment cordectomy was unsuccessful, spinal cordectomy with wide margin may be a possible treatment for
Journal of Clinical Neuroscience (2002) 9(2)