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Schwannomas of the falx
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Surg Neurol 1990;34:160-3
Schwannomas of the Falx Jestis V a q u e r o , M . D . , R o b e r t o M a r t i n e z , M . D . , S a n t i a g o C o c a , M . D . , and Inmaculada Vegazo, M.D. Departments of Neurosurgery and Pathology, Puerta de Hierro Clinic, Autonomous University, Madrid, Spain
Vaquero J, Martfnez R, Coca S, Vegazo I. Schwannomas of the falx. Surg Neurol 1990;34:160-3.
A case of multiple schwannomas arising from the falx in a 17-year-old girl, previously operated on for an intracerebral schwannoma, is presented. The appearance of multiple schwannomas has to be considered in the followup of the rare cases of intracranial schwannomas not related to cranial nerves. KEY W O R D S :
Schwannoma; Intracranial tumors; Meningeal
tumors
Introduction Intracranial schwannomas generally arise from the eighth cranial nerve; other cranial nerves are origins of these tumors less frequently [9]. There are very few reports about intraparenchymatous intracranial schwannomas. In the reported cases, the tumor was located within the cerebral hemispheres [2,4,5,7, 10,13,16,18], in the pons [ 12], in the medulla oblongata [1], within the cerebellum [8,15], or intrasellarly [6,11]. Following certain authors, undifferentiated mesenchymal cells and pial cells of the central nervous system (CNS) may become Schwann cells, which are considered to be the origin of these tumors [3]. On the other hand, foci of Schwann cells of hamartomatous character, and located within the substance of the brain, have been suggested as the origin of the intracerebral schwannomas in the rare cases reported [14]. We present the case of a girl with three macroscopically separated schwannomas in the falx. Seven years before, she was operated on for an intraparenchymatous frontomedial schwannoma [13].
Case R e p o r t A 17-year-old girl, without any stigmata of neurofibromatosis, underwent surgery when she was 10 years old for a left intraparenchymatous frontomedial schwannoma, which caused focal seizures. After complete removal the patient was symptom free for 5 years, then she began to have focal seizures again. At that time, computed tomography (CT) scan showed contrast-enhancing masses attached to the falx in the frontal region (Figure 1). Follow-up CT scans did not show any change for 2 years, but seizures were more frequent in spite of medical treatment. In December 1986, a new operation was decided upon. At surgery, three macroscopically separated tumors were resected, all of them tightly attached to the falx. Two of these tumors were growing toward the left hemisphere, one was pedicular, and the other one sessile. The
Figure 1. (Top row). Preoperative C T scan after administration of contrast medium. Numbers indicate the three separated schwannomas attached to the falx. A hypodense zone, corresponding to the previous left frontal lobectomy, can be seen. (Bottom row) Postoperative C T scan after administration of contrast medium, showing complete removal of the lesions.
Address reprint requests to:Jesfis Vaquero, M.D., Servicio de Neurocirugla, Clfnica Puerta de Hierro, San Martin de Porres, 4, 28035--Madrid, Spain. Received May 3, 1989; accepted March 6, 1990. © 1990 by Elsevier Science Publishing Co., Inc.
0090-3019/90/$3.50
Schwannomas of the Falx
A
third tumor spread toward the contralateral hemisphere, and it was adherent to the right pericallosal artery. The falx was not removed. The removed lesions were studied by light and electron microscopy. With hematoxylin and eosin stain, areas of spindle cells with elongated nuclei and eosinophilic cytoplasm appeared, and a diagnosis of schwannomas was suggested (Figure 2). Immunostain for glial fibriUary acidic protein, desmin, vimentin, and S-100 protein by means of avidin-biotin peroxidase technique
Surg Neurol 1990;34:160-3
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Figure 2. Photomicrographsof one of the excised tumors, showing spindle cells with elongated nuclei arranged in characteristic bundles (hematoxylin and eosin stain). Original magnification: (A) × 75, (B) x 125.
was performed. Only S-100 protein was diffusely positive (Figure 3), which has been previously described as characteristic of schwannomas [17]. Although tissue fixation for electron microscopy was deficient, ultrastructural study showed tumoral cells surrounded by basement membranes (Figure 4). These data led us to consider the removed tumors as schwannomas. The postoperative course of the patient was uneventful. She has not suffered any seizure since the operation 2 years ago.
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Surg Neurol 1990;34:160-3
Figure 3. lmmunostain for S-IO0 protein, showing positivity on the tumoral cells. Avidinbiotin peroxidase technique. Original magnification x 350.
Figure 4. Ultrastructural study of a removed lesion, showing tumoral cells surrounded by basement membranes. Ortginal magnification × 12,000.
Schwannomas of the Falx
Discussion In our opinion, the present case of falcine schwannomas is exceptional, and, as far as we know, there is no similar description among the small number of intracranial schwannomas not related to cranial nerves, except for two cases cited by Russell and Rubinstein [14]. Obviously, the precedent frontal schwannoma in this patient suggests that the origin of the now reported lesions could be the seeding of tumoral cells during previous surgery. Nevertheless, the presence of schwannoma at the right side of the falx led us to consider a proliferating substratum in these lesions, which happens in the more frequent cases of multiple meningiomas. This case, and the previous reports of intracranial schwannomas not related to the eighth cranial nerve, suggests that either a tumor recurrence [19] or the appearance of a new schwannoma may occur. These possibilities have to be considered in the followup of patients with such tumors. References 1. Aryanpur J, Long DM. Schwannoma of the medulla oblongata. Case report. J Neurosurg 1988;69:446-9. 2. Bruni P, Eposito S, Greco R, Oddi G. Solitary cerebral schwannoma in yon Recklinghausen's disease. Surg Neurol 1984; 22:360-4. 3. Feigin I, Ogata J. Schwann cells and peripheral myelin within human central nervous tissue: the mesenchymal character of Schwann cells. J Neuropathol Exp Neurol 1971;30:603-12. 4. Ghatak NR, Norwood CW, Davis CH. Intracerebral schwannoma. Surg Neurol 1975;3:45-7.
Surg N e u r o l 1990;34:160-3
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5. Gibson AAM, Hendrick EB, Conen PE. Intracerebral schwannoma. Report of a case. J Neurosurg 1966;24:552-7. 6. Goebel HH, Shimokawa K, Schaake T, Kremp A. Schwannoma of the sellar region. Acta Neurochir 1979;48:191-7. 7. G6kay H, Izgi N, Barlas O, Erseven G. Supratentorial intracerebral schwannomas. Surg Neurol 1984;22:69-72. 8. Komminoth R, Sokic P, Florange W. Schwannome intra-c6r6belleux. Neurochirurgie 1977;23:81-8. 9. Leunda G, Vaquero J, Cabezudo J, UriaJG, Bravo G. Schwannoma of the oculomotor nerves. Report of four cases. J Neurosurg 1982;57:563-5. 10. New PJ. Intracerebral schwannoma. Case report. J Neurosurg 1972;36:795-7. 11. Perone TP, Robinson B, Holmes SM. IntraseUar schwannoma: Case report. Neurosurgery 1984;14:71-3. 12. Prakash B, Roy S, Tandon PN. Schwannoma of the brain stem. Case report. J Neurosurg 1980;53:121-3. 13. Rodriguez-Salazar A, Carrillo R, de Miguel J. Intracerebral schwannoma in a child. Report of a case. Childs Brain 1984;11:69-72. 14. Russell DS, Rubinstein LJ. Pathology of tumours of the nervous system, ed 5. London: Edward Arnold, 1989. 15. Sarkar C, Mehta VS, Roy S. Intracerebellar schwannoma. Case report. J Neurosurg 1987;67:120-3. 16. Shalit MN, Toledo E, Sandbank U. Intracerebral schwannoma. Acta Neurochir 1982;64:253-8. 17. Stefansson K, Wollman R, Jerkovic M. S- 100 protein in soft-tissue tumors derived from Schwann cells and melanocytes. Am J Pathol 1982;106:261-8. 18. Van Rensburg MJ, Proctor NSF, Danziger J, Orelowitz MS. Temporal lobe epilepsy due to an intracerebral schwannoma: case report. J Neurol Neurosurg Psychiatry 1975;38:703-9. 19. Vaquero J, Martlnez R, Salazar J. Suprasellar recurrence of third nerve neurinoma (letter). J Neurosurg 1985;62:317.
Surg Neurol 1990;34:160-3
Schwannomas of the Falx Jestis V a q u e r o , M . D . , R o b e r t o M a r t i n e z , M . D . , S a n t i a g o C o c a , M . D . , and Inmaculada Vegazo, M.D. Departments of Neurosurgery and Pathology, Puerta de Hierro Clinic, Autonomous University, Madrid, Spain
Vaquero J, Martfnez R, Coca S, Vegazo I. Schwannomas of the falx. Surg Neurol 1990;34:160-3.
A case of multiple schwannomas arising from the falx in a 17-year-old girl, previously operated on for an intracerebral schwannoma, is presented. The appearance of multiple schwannomas has to be considered in the followup of the rare cases of intracranial schwannomas not related to cranial nerves. KEY W O R D S :
Schwannoma; Intracranial tumors; Meningeal
tumors
Introduction Intracranial schwannomas generally arise from the eighth cranial nerve; other cranial nerves are origins of these tumors less frequently [9]. There are very few reports about intraparenchymatous intracranial schwannomas. In the reported cases, the tumor was located within the cerebral hemispheres [2,4,5,7, 10,13,16,18], in the pons [ 12], in the medulla oblongata [1], within the cerebellum [8,15], or intrasellarly [6,11]. Following certain authors, undifferentiated mesenchymal cells and pial cells of the central nervous system (CNS) may become Schwann cells, which are considered to be the origin of these tumors [3]. On the other hand, foci of Schwann cells of hamartomatous character, and located within the substance of the brain, have been suggested as the origin of the intracerebral schwannomas in the rare cases reported [14]. We present the case of a girl with three macroscopically separated schwannomas in the falx. Seven years before, she was operated on for an intraparenchymatous frontomedial schwannoma [13].
Case R e p o r t A 17-year-old girl, without any stigmata of neurofibromatosis, underwent surgery when she was 10 years old for a left intraparenchymatous frontomedial schwannoma, which caused focal seizures. After complete removal the patient was symptom free for 5 years, then she began to have focal seizures again. At that time, computed tomography (CT) scan showed contrast-enhancing masses attached to the falx in the frontal region (Figure 1). Follow-up CT scans did not show any change for 2 years, but seizures were more frequent in spite of medical treatment. In December 1986, a new operation was decided upon. At surgery, three macroscopically separated tumors were resected, all of them tightly attached to the falx. Two of these tumors were growing toward the left hemisphere, one was pedicular, and the other one sessile. The
Figure 1. (Top row). Preoperative C T scan after administration of contrast medium. Numbers indicate the three separated schwannomas attached to the falx. A hypodense zone, corresponding to the previous left frontal lobectomy, can be seen. (Bottom row) Postoperative C T scan after administration of contrast medium, showing complete removal of the lesions.
Address reprint requests to:Jesfis Vaquero, M.D., Servicio de Neurocirugla, Clfnica Puerta de Hierro, San Martin de Porres, 4, 28035--Madrid, Spain. Received May 3, 1989; accepted March 6, 1990. © 1990 by Elsevier Science Publishing Co., Inc.
0090-3019/90/$3.50
Schwannomas of the Falx
A
third tumor spread toward the contralateral hemisphere, and it was adherent to the right pericallosal artery. The falx was not removed. The removed lesions were studied by light and electron microscopy. With hematoxylin and eosin stain, areas of spindle cells with elongated nuclei and eosinophilic cytoplasm appeared, and a diagnosis of schwannomas was suggested (Figure 2). Immunostain for glial fibriUary acidic protein, desmin, vimentin, and S-100 protein by means of avidin-biotin peroxidase technique
Surg Neurol 1990;34:160-3
161
Figure 2. Photomicrographsof one of the excised tumors, showing spindle cells with elongated nuclei arranged in characteristic bundles (hematoxylin and eosin stain). Original magnification: (A) × 75, (B) x 125.
was performed. Only S-100 protein was diffusely positive (Figure 3), which has been previously described as characteristic of schwannomas [17]. Although tissue fixation for electron microscopy was deficient, ultrastructural study showed tumoral cells surrounded by basement membranes (Figure 4). These data led us to consider the removed tumors as schwannomas. The postoperative course of the patient was uneventful. She has not suffered any seizure since the operation 2 years ago.
162
Surg Neurol 1990;34:160-3
Figure 3. lmmunostain for S-IO0 protein, showing positivity on the tumoral cells. Avidinbiotin peroxidase technique. Original magnification x 350.
Figure 4. Ultrastructural study of a removed lesion, showing tumoral cells surrounded by basement membranes. Ortginal magnification × 12,000.
Schwannomas of the Falx
Discussion In our opinion, the present case of falcine schwannomas is exceptional, and, as far as we know, there is no similar description among the small number of intracranial schwannomas not related to cranial nerves, except for two cases cited by Russell and Rubinstein [14]. Obviously, the precedent frontal schwannoma in this patient suggests that the origin of the now reported lesions could be the seeding of tumoral cells during previous surgery. Nevertheless, the presence of schwannoma at the right side of the falx led us to consider a proliferating substratum in these lesions, which happens in the more frequent cases of multiple meningiomas. This case, and the previous reports of intracranial schwannomas not related to the eighth cranial nerve, suggests that either a tumor recurrence [19] or the appearance of a new schwannoma may occur. These possibilities have to be considered in the followup of patients with such tumors. References 1. Aryanpur J, Long DM. Schwannoma of the medulla oblongata. Case report. J Neurosurg 1988;69:446-9. 2. Bruni P, Eposito S, Greco R, Oddi G. Solitary cerebral schwannoma in yon Recklinghausen's disease. Surg Neurol 1984; 22:360-4. 3. Feigin I, Ogata J. Schwann cells and peripheral myelin within human central nervous tissue: the mesenchymal character of Schwann cells. J Neuropathol Exp Neurol 1971;30:603-12. 4. Ghatak NR, Norwood CW, Davis CH. Intracerebral schwannoma. Surg Neurol 1975;3:45-7.
Surg N e u r o l 1990;34:160-3
163
5. Gibson AAM, Hendrick EB, Conen PE. Intracerebral schwannoma. Report of a case. J Neurosurg 1966;24:552-7. 6. Goebel HH, Shimokawa K, Schaake T, Kremp A. Schwannoma of the sellar region. Acta Neurochir 1979;48:191-7. 7. G6kay H, Izgi N, Barlas O, Erseven G. Supratentorial intracerebral schwannomas. Surg Neurol 1984;22:69-72. 8. Komminoth R, Sokic P, Florange W. Schwannome intra-c6r6belleux. Neurochirurgie 1977;23:81-8. 9. Leunda G, Vaquero J, Cabezudo J, UriaJG, Bravo G. Schwannoma of the oculomotor nerves. Report of four cases. J Neurosurg 1982;57:563-5. 10. New PJ. Intracerebral schwannoma. Case report. J Neurosurg 1972;36:795-7. 11. Perone TP, Robinson B, Holmes SM. IntraseUar schwannoma: Case report. Neurosurgery 1984;14:71-3. 12. Prakash B, Roy S, Tandon PN. Schwannoma of the brain stem. Case report. J Neurosurg 1980;53:121-3. 13. Rodriguez-Salazar A, Carrillo R, de Miguel J. Intracerebral schwannoma in a child. Report of a case. Childs Brain 1984;11:69-72. 14. Russell DS, Rubinstein LJ. Pathology of tumours of the nervous system, ed 5. London: Edward Arnold, 1989. 15. Sarkar C, Mehta VS, Roy S. Intracerebellar schwannoma. Case report. J Neurosurg 1987;67:120-3. 16. Shalit MN, Toledo E, Sandbank U. Intracerebral schwannoma. Acta Neurochir 1982;64:253-8. 17. Stefansson K, Wollman R, Jerkovic M. S- 100 protein in soft-tissue tumors derived from Schwann cells and melanocytes. Am J Pathol 1982;106:261-8. 18. Van Rensburg MJ, Proctor NSF, Danziger J, Orelowitz MS. Temporal lobe epilepsy due to an intracerebral schwannoma: case report. J Neurol Neurosurg Psychiatry 1975;38:703-9. 19. Vaquero J, Martlnez R, Salazar J. Suprasellar recurrence of third nerve neurinoma (letter). J Neurosurg 1985;62:317.