J Neurosurg 77:640-642, 1992
Intracranial lipoma associated with cerebral saccular aneurysm Case report KAZUYA FUTAMI, M.D., AKIRA KIMURA, M.D., AND JUNKOH YAMASHITA, M.D.
Department of Neurosurgery. Matsuto-lshikawa Central Hospital, and Department of Neurosurgery, Kanazawa University, School of Medicine, Kanazawa, Japan v" The afithors present a case of lipoma in the sylvian fissure associated with a saccular aneurysm of the middle cerebral artery. The aneurysm was successfully clipped following the partial resection of the tumor. This is the first reported case of this combined pathology. The value of cerebral angiography in this disease entity and the possible etiology of the association of an aneurysm with a lipoma are discussed. KEY WORDS angiography
~
intracranial lipoma
NTRACRANIALlipomas are rare and are commonly located in the callosal, quadrigeminal, or suprasellar cistern. 7"~~ Lipomas in the sylvian fissure are exceptional. ~.3.6,9.~0,~4These tumors are frequently associated not only with maldevelopment of the central nervous system, 2"~'~'~4 but also with abnormalities of the cerebral arteries such as an azygous anterior cerebral artery ( A C A ) 2'11 or fusiform dilatation 4"5'~2-~3of associated vessels. However, lipomas associated with a saccular cerebral aneurysm are extremely rare. TM~6 In this paper, we report the first case of an intracranial lipoma in the sylvian fissure incorporating a saceular aneurysm of the middle cerebral artery (MCA).
I
9 sylvian fissure
9 saecular aneurysm
9
Magnetic resonance (MR) imaging showed the mass lesion as markedly hyperintense on TL-weighted and isointense on T2-weighted images (Fig. 2), consistent with adipose tissue. The low-density area in the fight putamen on CT scans appeared hypointense on T,weighted and hypefintense on T2-weighted MR images.
Case Report This 26-year-old woman was admitted to MatsutoIshikawa Central Hospital on February 2, 1991, with the chief complaint of a migrainous headache. Her medical and familial history was unremarkable.
Examination. Physical and neurological examination on admission were within normal limits. Plain skull x-ray films showed the presence of intracranial calcification in the right frontotemporal region. Computerized tomography (CT) scans of the brain revealed a mass lesion of extremely low density in the fight sylvian fissure with curvilinear calcification at the posterior aspect of the lesion (Fig. 1) and a low-density area in the fight putamen adjacent to the mass lesion. 640
FIG. 1. Computerized tomography scan showing a very low-density mass lesion in the right sylvian fissure with curvilinear calcification at the posterior margin of the lesion.
J. Neurosurg. / Volume 77/October, 1992
Lipoma associated with cerebral saccular aneurysm aneurysmal neck was coated with a yellowish adipose tumor; after partial removal of the tumor, the neck was exposed and successfully clipped. Histological examination revealed the tumor to be composed of welldifferentiated adipose tissue indicative of lipoma.
Postoperative Com~e. The patient's postoperative course was uneventful. She was discharged home on the 9th postoperative day. Discussion
FIG. 2. Magnetic resonance images showing a mass exhibiting marked hyperintensity on the Tj-weighted image (A) and isointensity on the T~-weighted image (B), consistent with adipose tissue. The low-density area in the right putamen on computerized tomography (not shown) was revealed as hypointensity on the Tt-weighted image. The right middle cerebral artery could be detected as a signal-void area along the lesion, associated with an aneurysmal dilatation (arrowhead).
The fight MCA could be detected as a signal-void area along the lesion associated with what appeared to be an aneurysmal dilatation. Right carotid angiography revealed a saccular aneurysm, 7 • 6 • 6 mm in size, at the MCA bifurcation and an adjacent fine vascular blush (Fig. 3 left). The patient was diagnosed as having a lipoma in the sylvian fissure associated with an unruptured saccular aneurysm at the MCA bifurcation and putaminal infarction.
Operation. Considering the young age of the patient, we decided to operate on the aneurysm. A right frontotemporal craniotomy was performed and, with the aid of an operating microscope, the aneurysm was disclosed in the fight sylvian fissure (Fig. 3 right). The
Since a lipoma of the corpus callosum was first described in 1856 by yon Rokitansky, ~5 reports of intracranial lipomas have increased. The most common site of intracranial lipomas is the callosal cistern, accounting for 50% of the large series of 203 cases reviewed by Maiuri, et al. 1oLipomas in the sylvian fissure are exceptional, '-36~'~ with an incidence of 3.4% in the series of Maiuri, et al., and 5% in the 44 intracranial lipomas reported by Truwit and Barkovich. ~ Most reviews of intracranial lipomas have largely dealt with the association of maldevelopment of the central nervous system, including agenesis of the corpus callosum2 5 ' ' ' ' 4 However, observations from several cerebral angiographic studies demonstrated abnormalities of the cerebral arteries contiguous with the tumor, such as fusiform aneurysms 4~'12'13and azygous ACA's. 2 t Surprisingly, the association with fusiform aneurysm is not rare; Eldevik and Gabrielsen 4 identified fusiform aneurysms in 19 of 22 cases with lipoma of the corpus callosum in their review of the previous literature. Meanwhile, only two reports of lipomas associated with saccular cerebral aneurysm were presented. T M Nakamura, et al., '~ described a 53-year-old woman who had experienced subarachnoid hemorrhage due to a ruptured azygous ACA aneurysm accompanied by a lipoma of the corpus callosum. Yamamoto, et al., ~6
FIG. 3. Left: Right carotid angiogram, lateral view, showing a saccular aneurysm (arrow) at the middle cerebral artery (MCA) bifurcation and a fine vascular blush. Right: Intraoperative photograph showing an aneurysm (arrowhead) and the M~ segment (,single arrow) and M2 segment (double arroa9 of the right MCA, surrounded by adipose tissue (Y).
J. Neurosurg. / Volume 77/October, 1992
641
K. Futami, A. Kimura, and J. Yamashita reported a 52-year-old woman with a lipoma of the corpus callosum associated with an unruptured distal ACA aneurysm. Since the introduction of CT and MR imaging, the diagnostic value of cerebral angiography has decreased. 7,9.14 However, considering the frequent association of vascular abnormalities, the value of cerebral angiography should be re-emphasized in cases of intracranial lipoma. The etiology of saccular or fusiform aneurysms accompanied by intracranial lipomas is obscure. It is assumed that intracranial tipomas have a malformative origin arising from the persistence and abnormal differentiation of the primitive meninx, s' J4~s Therefore, these aneurysms could be attributed to a congenital structural deficiency of the cerebral vessel which occurred at the same time as the formation of a lipoma. One other possibility is that the lipoma itself might degenerate the cerebral arterial wall. Zervas, et al., ~7 suggested that cerebrovascular smooth muscle may receive its nutrition via diffusion from subarachnoid cerebrospinal fluid since the cerebral arteries do not have vasa vasorum. The presence of a lipoma may eliminate the nutrition to the cerebral arterial wall incorporated within the tumor. As another hypothesis, these tumors might secrete some factors inhibiting the growth of arterial smooth muscle, thereby weakening the arterial wall to hemodynamic stress. Further studies are needed to verify any of these hypotheses. References 1. B6ker DK, Sartor K, Penkert G: Computertomographisches und angiographisches Erscheinungsbild gef~issreicher intrakranieller Lipome (Angiolipome). ROFO 135:695-698, 1981 2. Danziger J, Bloch S, Van Rensburg MJ: Agenesis of the corpus callosum associated with an azygos anterior cerebral artery, a lipoma and porencephalie cyst. S Afr Med J 46:739-741, 1972 3. Dyck P: Sylvian lipoma causing auditory hallucinations: case report. Neurosurgery 16:64-67, 1985 4. Eldevik OP, Gabrielsen TO: Fusiform aneurysmal dilatation of pericallosal artery. A sign of lipoma of corpus callosum. Acta Radiol (Suppl) 347:71-76, 1975
642
5. Gerber SS, Plotkin R: Lipoma of the corpus callosum. Case report. J Neurosurg 57:281-285, 1982 6. Hatashita S, Sakakibara T, Ishii S: Lipoma of the insula. Case report. J Neurosurg 58:300-302, 1983 7. Kazner E, Stochdorph O, Wende S, et al: Intracranial lipomas. Diagnostic and therapeutic considerations. J Neurosurg 52:234-245, 1980 8. List CF, Holt JF, Everett M: Lipoma of the corpus callosum. A clinicopathologic study. AJNR 55:125-134, 1946 9. Maiuri F, Cirillo S, Simonetti L: Lipoma of the Sylvian region. Clin Neurol Neurosurg 91:321-323, t989 10. Maiuri F, Cirillo S, Simonetti L, et al: Intracranial lipoma. Diagnostic and therapeutic considerations. J Neurosurg Sci 32:161-167, 1988 11. Nakamura N, Ogawa A, Kayama T, el al: [A case of agenesis of the corpus callosum accompanied with a ruptured azygos anterior cerebral artery aneurysm and lipoma - - a case report.] No To Shinkei 38:701-705, 1986 (Jpn) 12. Roukkula M, Anttinen EE: Lipoma of the corpus callosum. Clinical and roentgenological aspect. Ann Chir Gynaecol Fenn 51:228-237, 1962 13. Sabouraud O, Pecker J, Simon P, et al: Lipomes du corps calleux. Donnres angiographiques et discussion pathogrnique de leur srmriologie clinique. Rev Neurol 117: 557-570, 1967 14. Truwit CL, Barkovich AJ: Pathogenesis of intracranial lipoma: an MR study in 42 patients. AJR 155:855-864, 1990 15. von Rokitansky C: Lehrbuch der pathologischen Anatorole. Vienna: Wilhelm Braumuller, 1856, Vol 2, p 468 16. Yamamoto M, Kuwabara S, Uozumi T: Lipoma of the corpus callosum associated with distal anterior cerebral artery aneurysm. A case report. Hiroshima J Med Sci 38: 157-160, 1989 17. Zervas NT, Liszczak TM, Mayberg MR, et al: Cerebrospinal fluid may nourish cerebral vessels through pathways in the adventitia that may be analogous to systemic vasa vasorum. J Neurosurg 56:475-481, 1982 18. Zettner A, Netsky MG: Lipoma of the corpus callosum. J Neuropathol Exp Neurol 19:305-319, 1960 Manuscript received November 20, 1991. Accepted in final form March 10, 1992. Address reprint requests to: Kazuya Futami, M.D., Department of Neurosurgery, Kanazawa University, School of Medicine, 13-1 Takaramachi, Kanazawa 920, Japan.
J. Neurosurg. / Volume 77/October, t992
Intracranial lipoma associated with cerebral saccular aneurysm Case report KAZUYA FUTAMI, M.D., AKIRA KIMURA, M.D., AND JUNKOH YAMASHITA, M.D.
Department of Neurosurgery. Matsuto-lshikawa Central Hospital, and Department of Neurosurgery, Kanazawa University, School of Medicine, Kanazawa, Japan v" The afithors present a case of lipoma in the sylvian fissure associated with a saccular aneurysm of the middle cerebral artery. The aneurysm was successfully clipped following the partial resection of the tumor. This is the first reported case of this combined pathology. The value of cerebral angiography in this disease entity and the possible etiology of the association of an aneurysm with a lipoma are discussed. KEY WORDS angiography
~
intracranial lipoma
NTRACRANIALlipomas are rare and are commonly located in the callosal, quadrigeminal, or suprasellar cistern. 7"~~ Lipomas in the sylvian fissure are exceptional. ~.3.6,9.~0,~4These tumors are frequently associated not only with maldevelopment of the central nervous system, 2"~'~'~4 but also with abnormalities of the cerebral arteries such as an azygous anterior cerebral artery ( A C A ) 2'11 or fusiform dilatation 4"5'~2-~3of associated vessels. However, lipomas associated with a saccular cerebral aneurysm are extremely rare. TM~6 In this paper, we report the first case of an intracranial lipoma in the sylvian fissure incorporating a saceular aneurysm of the middle cerebral artery (MCA).
I
9 sylvian fissure
9 saecular aneurysm
9
Magnetic resonance (MR) imaging showed the mass lesion as markedly hyperintense on TL-weighted and isointense on T2-weighted images (Fig. 2), consistent with adipose tissue. The low-density area in the fight putamen on CT scans appeared hypointense on T,weighted and hypefintense on T2-weighted MR images.
Case Report This 26-year-old woman was admitted to MatsutoIshikawa Central Hospital on February 2, 1991, with the chief complaint of a migrainous headache. Her medical and familial history was unremarkable.
Examination. Physical and neurological examination on admission were within normal limits. Plain skull x-ray films showed the presence of intracranial calcification in the right frontotemporal region. Computerized tomography (CT) scans of the brain revealed a mass lesion of extremely low density in the fight sylvian fissure with curvilinear calcification at the posterior aspect of the lesion (Fig. 1) and a low-density area in the fight putamen adjacent to the mass lesion. 640
FIG. 1. Computerized tomography scan showing a very low-density mass lesion in the right sylvian fissure with curvilinear calcification at the posterior margin of the lesion.
J. Neurosurg. / Volume 77/October, 1992
Lipoma associated with cerebral saccular aneurysm aneurysmal neck was coated with a yellowish adipose tumor; after partial removal of the tumor, the neck was exposed and successfully clipped. Histological examination revealed the tumor to be composed of welldifferentiated adipose tissue indicative of lipoma.
Postoperative Com~e. The patient's postoperative course was uneventful. She was discharged home on the 9th postoperative day. Discussion
FIG. 2. Magnetic resonance images showing a mass exhibiting marked hyperintensity on the Tj-weighted image (A) and isointensity on the T~-weighted image (B), consistent with adipose tissue. The low-density area in the right putamen on computerized tomography (not shown) was revealed as hypointensity on the Tt-weighted image. The right middle cerebral artery could be detected as a signal-void area along the lesion, associated with an aneurysmal dilatation (arrowhead).
The fight MCA could be detected as a signal-void area along the lesion associated with what appeared to be an aneurysmal dilatation. Right carotid angiography revealed a saccular aneurysm, 7 • 6 • 6 mm in size, at the MCA bifurcation and an adjacent fine vascular blush (Fig. 3 left). The patient was diagnosed as having a lipoma in the sylvian fissure associated with an unruptured saccular aneurysm at the MCA bifurcation and putaminal infarction.
Operation. Considering the young age of the patient, we decided to operate on the aneurysm. A right frontotemporal craniotomy was performed and, with the aid of an operating microscope, the aneurysm was disclosed in the fight sylvian fissure (Fig. 3 right). The
Since a lipoma of the corpus callosum was first described in 1856 by yon Rokitansky, ~5 reports of intracranial lipomas have increased. The most common site of intracranial lipomas is the callosal cistern, accounting for 50% of the large series of 203 cases reviewed by Maiuri, et al. 1oLipomas in the sylvian fissure are exceptional, '-36~'~ with an incidence of 3.4% in the series of Maiuri, et al., and 5% in the 44 intracranial lipomas reported by Truwit and Barkovich. ~ Most reviews of intracranial lipomas have largely dealt with the association of maldevelopment of the central nervous system, including agenesis of the corpus callosum2 5 ' ' ' ' 4 However, observations from several cerebral angiographic studies demonstrated abnormalities of the cerebral arteries contiguous with the tumor, such as fusiform aneurysms 4~'12'13and azygous ACA's. 2 t Surprisingly, the association with fusiform aneurysm is not rare; Eldevik and Gabrielsen 4 identified fusiform aneurysms in 19 of 22 cases with lipoma of the corpus callosum in their review of the previous literature. Meanwhile, only two reports of lipomas associated with saccular cerebral aneurysm were presented. T M Nakamura, et al., '~ described a 53-year-old woman who had experienced subarachnoid hemorrhage due to a ruptured azygous ACA aneurysm accompanied by a lipoma of the corpus callosum. Yamamoto, et al., ~6
FIG. 3. Left: Right carotid angiogram, lateral view, showing a saccular aneurysm (arrow) at the middle cerebral artery (MCA) bifurcation and a fine vascular blush. Right: Intraoperative photograph showing an aneurysm (arrowhead) and the M~ segment (,single arrow) and M2 segment (double arroa9 of the right MCA, surrounded by adipose tissue (Y).
J. Neurosurg. / Volume 77/October, 1992
641
K. Futami, A. Kimura, and J. Yamashita reported a 52-year-old woman with a lipoma of the corpus callosum associated with an unruptured distal ACA aneurysm. Since the introduction of CT and MR imaging, the diagnostic value of cerebral angiography has decreased. 7,9.14 However, considering the frequent association of vascular abnormalities, the value of cerebral angiography should be re-emphasized in cases of intracranial lipoma. The etiology of saccular or fusiform aneurysms accompanied by intracranial lipomas is obscure. It is assumed that intracranial tipomas have a malformative origin arising from the persistence and abnormal differentiation of the primitive meninx, s' J4~s Therefore, these aneurysms could be attributed to a congenital structural deficiency of the cerebral vessel which occurred at the same time as the formation of a lipoma. One other possibility is that the lipoma itself might degenerate the cerebral arterial wall. Zervas, et al., ~7 suggested that cerebrovascular smooth muscle may receive its nutrition via diffusion from subarachnoid cerebrospinal fluid since the cerebral arteries do not have vasa vasorum. The presence of a lipoma may eliminate the nutrition to the cerebral arterial wall incorporated within the tumor. As another hypothesis, these tumors might secrete some factors inhibiting the growth of arterial smooth muscle, thereby weakening the arterial wall to hemodynamic stress. Further studies are needed to verify any of these hypotheses. References 1. B6ker DK, Sartor K, Penkert G: Computertomographisches und angiographisches Erscheinungsbild gef~issreicher intrakranieller Lipome (Angiolipome). ROFO 135:695-698, 1981 2. Danziger J, Bloch S, Van Rensburg MJ: Agenesis of the corpus callosum associated with an azygos anterior cerebral artery, a lipoma and porencephalie cyst. S Afr Med J 46:739-741, 1972 3. Dyck P: Sylvian lipoma causing auditory hallucinations: case report. Neurosurgery 16:64-67, 1985 4. Eldevik OP, Gabrielsen TO: Fusiform aneurysmal dilatation of pericallosal artery. A sign of lipoma of corpus callosum. Acta Radiol (Suppl) 347:71-76, 1975
642
5. Gerber SS, Plotkin R: Lipoma of the corpus callosum. Case report. J Neurosurg 57:281-285, 1982 6. Hatashita S, Sakakibara T, Ishii S: Lipoma of the insula. Case report. J Neurosurg 58:300-302, 1983 7. Kazner E, Stochdorph O, Wende S, et al: Intracranial lipomas. Diagnostic and therapeutic considerations. J Neurosurg 52:234-245, 1980 8. List CF, Holt JF, Everett M: Lipoma of the corpus callosum. A clinicopathologic study. AJNR 55:125-134, 1946 9. Maiuri F, Cirillo S, Simonetti L: Lipoma of the Sylvian region. Clin Neurol Neurosurg 91:321-323, t989 10. Maiuri F, Cirillo S, Simonetti L, et al: Intracranial lipoma. Diagnostic and therapeutic considerations. J Neurosurg Sci 32:161-167, 1988 11. Nakamura N, Ogawa A, Kayama T, el al: [A case of agenesis of the corpus callosum accompanied with a ruptured azygos anterior cerebral artery aneurysm and lipoma - - a case report.] No To Shinkei 38:701-705, 1986 (Jpn) 12. Roukkula M, Anttinen EE: Lipoma of the corpus callosum. Clinical and roentgenological aspect. Ann Chir Gynaecol Fenn 51:228-237, 1962 13. Sabouraud O, Pecker J, Simon P, et al: Lipomes du corps calleux. Donnres angiographiques et discussion pathogrnique de leur srmriologie clinique. Rev Neurol 117: 557-570, 1967 14. Truwit CL, Barkovich AJ: Pathogenesis of intracranial lipoma: an MR study in 42 patients. AJR 155:855-864, 1990 15. von Rokitansky C: Lehrbuch der pathologischen Anatorole. Vienna: Wilhelm Braumuller, 1856, Vol 2, p 468 16. Yamamoto M, Kuwabara S, Uozumi T: Lipoma of the corpus callosum associated with distal anterior cerebral artery aneurysm. A case report. Hiroshima J Med Sci 38: 157-160, 1989 17. Zervas NT, Liszczak TM, Mayberg MR, et al: Cerebrospinal fluid may nourish cerebral vessels through pathways in the adventitia that may be analogous to systemic vasa vasorum. J Neurosurg 56:475-481, 1982 18. Zettner A, Netsky MG: Lipoma of the corpus callosum. J Neuropathol Exp Neurol 19:305-319, 1960 Manuscript received November 20, 1991. Accepted in final form March 10, 1992. Address reprint requests to: Kazuya Futami, M.D., Department of Neurosurgery, Kanazawa University, School of Medicine, 13-1 Takaramachi, Kanazawa 920, Japan.
J. Neurosurg. / Volume 77/October, t992
