Surg Neurol 1992;38:257-60
Cavernous Angioma of the Posterior Fossa Dura Mimicking a Meningioma: Case Report and Review of Literature Sumeer Sathi, M.D., Rebecca Folkerth, M.D., and Joseph R. Madsen, M.D. Department of Neurosurgery, Children's Hospital, Division of Neurosurgery and Department of Pathology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
Sathi S, Folkerth R, Madsen J. Cavernous angioma of the posterior fossa dura mimicking a meningioma: case report and review of literature. Surg Neurol 1992;38:257-60.
A cavernous angioma of the posterior fossa dura was discovered incidentally on neuroimaging studies. The clinical and pathologic features of this lesion are described. Although it has been reported to arise in the posterior fossa and the tentorium cerebelli, we present the first case of such a malformation arising from the dura of the posterior fossa. KEYWORDS- Cavernous angioma; Posterior fossa; Dura; Meningioma
Cavernous angiomas o f the dura are rare and have been described in the literature particularly in the middle fossa [ 2 , 4 - 6 , 8 - 1 1 ] . In the posterior fossa, extracerebral cavernous angiomas have been noted in the tentorium cerebelli and the internal auditory canal [7,9,14]. We present a case report o f a cavernous angioma o f the posterior fossa dura. T o our knowledge, this is the first report describing a cavernous angioma in such a location.
Case Report A 61-year-old man with a long history of pipe smoking presented to the otolaryngology service for evaluation o f a tongue lesion. His physical examination was notable for trace dysmetria on the right side and very slight instability on tandem walking. H e also had guaiac-positive stools. Otherwise, his physical and neurologic examinations were normal. A preoperative magnetic resonance imaging (MRI) scan obtained for surgical planning disclosed an unexpected 2 x 4-cm round lesion in the vicinity of the right cerebellar tonsil (Figure 1). This had a low T1 and an
Address reprint requests to: Sumeer Sathi, M.D., Department of Neurosurgery, Children's Hospital, 300 Longwood Avenue, Boston, Massachusetts 02115. Received May 15, 1992; accepted June 30, 1992.
© 1992 by Elsevier Science Publishing Co., Inc.
intermediate T2 signal. Further, it enhanced homogeneously with gadolinium (Figure 2). A computed tomographic (CT) scan revealed a hyperdense mass in the right posterior fossa that enhanced intensely with contrast (Figure 3). This lesion was not associated with significant edema o f the adjacent brain, and there was no hydrocephalus. Imaging studies did not clearly differentiate an intra-axial from an extra-axial lesion. The patient underwent a right hemiglossectomy, which revealed a well-differentiated squamous cell carcinoma. The differential diagnosis of the posterior fossa lesion included metastatic tumor and primary meningioma. Given his guaiac-positive stools, a colonoscopy was performed, which revealed a lesion in the sigmoid colon, and biopsy revealed a villous adenoma. In consideration of the low likelihood o f a squamous cell carcinoma o f the tongue producing brain metastases, meningioma was the favored diagnosis. Therefore, the decision was made to resect the posterior fossa lesion to obtain a diagnosis and to prevent emergence o f pressure symptoms in the posterior fossa. A right-sided suboccipital craniectomy was performed. T h e dura appeared slightly thickened and was firm in the area o f the mass. The dura was o p e n e d away from this area of abnormality, and a dural-based tumor was found. The dura was incised circumferentially around the tumor attachment. By retracting on the base of this tumor, it was possible to dissect a plane between it and the cerebellum. T h e appearance at the time of surgery was characteristic of a meningioma. T h e r e was no evidence o f invasion o f the bone or adjacent brain. The lesion was extra-arachnoid, and the cerebellar folia appeared compressed. T h e dura was closed with a patch graft. Postoperatively, the patient did very well, and his dysmetria and gait incoordination resolved. Gross examination of the excised tumor revealed a red-brown to purple nodular mass, measuring 2.5 x 2.0 x 2.0 cm. It was affixed to the dura, without gross evidence of invasion through it. On cut section, the tissue presented a spongelike appearance with multiple blood-filled spaces. Microscopically, the tumor was 0090-3019/92/$5.00
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Figure 1. Sagittal Tl-weighted MR1 scan revealing a low-signal mass in the vicinity of the right cerebellar tonsil.
Figure 3. CT scan after contrast demonstrating homogeneous, intense Figure 2. Axial Tl-weighted MRI scan showing intense enhancement of the mass in the right cerebellum after injection of gadolinium.
enhancement of the right cerebellar lesion, suspicious for arising from the aura.
made up of dilated blood-containing channels lined with flattened endothelium separated by dense fibroid tissue devoid of elastica and reticulin (Figure 4). The cavernous angioma arose from the dura, as seen in the photomicrograph. Luminal thrombi of varying ages were frequently seen. A diagnosis of a cavernous hemangioma was made.
Discussion Cavernous angiomas are rare lesions that represent 5 % to 13 % of the central nervous system vascular malformations . These lesions most commonly involve the cerebral hemispheres, especially the parietal lobe and basal ganglia . Intracranial extracerebral cavernous angiomas are extremely unusual. These malformations have been noted most often in the middle fossa and involve the parasellar area , cavernous sinus [9,10], Meckel's cave , tegmen tympani , and dura overlying the temporal lobe [4,5]. In the posterior fossa, extracerebral cavernous angiomas have also been described in the tentorium cerebeUi [7,9] and the internal auditory canal . Dandy reported a large cavernoma in an infant that occupied the
Cavernous Angioma of Posterior Fossa Dura
Figure 4. Cavernous hemangioma arising from the dura (seen in the upper left corner) and made up of multiple endothelial-lined, blood-filled channels of varying sizes. (Hematoxylin and eosin stain, original magnification × 200.)
posterior fossa and the suboccipital extracranial region with communication through holes in the occipital bone . The two cases of the dural cavernous angiomas in the tentorium cerebelli described by McCormick and Boulter were noted on autopsy in patients who had died of systemic causes . Moritake et al described a cavernous angioma of the tentorium cerebelli discovered by perinatal serial ultrasonography in a neonate . The present case of a cavernous angioma of the dura is unique with respect to its location, which may explain its clinical presentation and radiographic features. The lesion in the present case also was noted on incidental neuroimaging studies obtained for staging for surgery of tongue squamous cell carcinoma. Only on careful neurological examination was the patient noted to have subtle dysmetria and incoordination. It is certainly possible that the incidence of these lesions is much higher; however, given their size and location in the posterior fossa, they probably do not produce symptoms as readily
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as the lesions in the middle fossa, which may involve the optic nerves or the cranial nerves in the cavernous sinus. The MRI scan of an intracerebral cavernous angioma usually shows a combination of a reticulated core of mixed signal intensity especially on T2-weighted images, with a surrounding rim of decreased signal intensity [3,12]. The MRI scan of the dural cavernous angioma in this case was different probably because of the lack of previous hemorrhages, which have been previously noted in the middle fossa . Moreover, the CT scan of this lesion showed a high-density mass with homogeneous enhancement. Both the MRI and CT images revealed this lesion to be indistinguishable from a meningioma. Although intracerebral cavernous angiomas have been widely known and discussed in the neurosurgical community, the possibility that angiomatous malformations of the dura may also present as mass lesions has received relatively little attention. Lesions such as the one under discussion would probably be confused with other dural-based lesions such as meningiomas, when detected radiographically. The natural history of dural cavernous angiomas is entirely unknown, but the lack of reports of such lesions with significant sequelae may
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argue for a very benign clinical course. The same argument could have been made about cavernous angiomas of the brain parenchyma, which are now thought to be lesions worthy of neurosurgical attack. Further observation and study of dural cavernous angiomas will be necessary to understand their differential diagnostic characteristics, as well as their optimal management.
References 1. Dandy W. Venous abnormalities and angiomas of the brain. Arch Surg 1928,17:715-93. 2. Fehlings MG, Tucker WS. Cavernous hemangioma of Meckel's cave. J Neurosurg 1988;68:645-7. 3. GomoriJM, Grossman RI, Goldgerg HI, Hackney DB, Zimmerman RA, Bilaniuk LT. Occult cerebral vascular malformations: High-field MR imaging. Radiology 1988;158:707-13. 4. Ishijima Y, Matsumura H, Kageyma N. Intracranial cavernous hemangioma: report of two cases. ArchJpn Chir 1966;35:748-54. 5. Kawaguchi S, Osawa T. A case of cavernous hemangioma at the base of the skull. Clin Neurol 1965;5:705-7.
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6. Kawai K, Fukui M, Tanaka A, Kuramoto S, Kitamura K. Extracerebral cavernous hemangioma of the middle fossa. Surg Neurol 1978;9:19-25. 7. McCormick WF, Boulter TR. Vascular malformations Cangiomas") of the dura mater: report of two cases. J Neurosurg 1966;25:309-11. 8. Mori K, Handa H, Gi H, Mori K. Cavernomas in the middle fossa. Surg Neurol 1980;14:21-31. 9. Moritake K, Handa H, Nozaki K, Tomiwa K. Tentorial cavernous angioma with calcification in a neonate. Neurosurgery 1985; 16:207-11. 10. Namba S. Extracerebral cavernous hemangioma of the middle cranial fossa. Surg Neurol 1983;19:379-88. 11. Pozzati E, Giuliani G, Ferracini R, Gaist G. Facial nerve palsy secondary to a dural cavernous angioma of the middle cranial fossa eroding the tegmen tympani. Neurosurgery 1988;23:245-7. 12. 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. 13. gussel DS, Rubinstein LJ. Pathology of tumours of the nervous system, 4th ed. Baltimore: Williams & Wilkins, 1977:127-41. 14. Sundaresan N, EUer T, Ciric I. Hemangiomas of the internal auditory canal. Surg Neurol 1976;6:119-21. 15. Wilkins RH. Natural history of intracranial vascular malformations: a review. Neurosurgery 1985;16:421-30.