Surgical Neurology 63 (2005) 178 – 181 www.surgicalneurology-online.com
Dural cavernous angioma of the posterior sagittal sinus: case report John A. Boockvar, MDa,*, Michael Stiefel, MDa, Neil Malhotra, MDa, Carol Dolinskas, MDb, Carol Dwyer-Joyce, MDc, Peter D. LeRoux, MDa a Weill Cornell Medical College, New York, NY 10021, USA Departments of bRadiology and cPathology, Pennsylvania Hospital, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA Received 28 July 2003; accepted 10 March 2004
Background: Extraaxial cavernous hemangiomas (cavernomas) are very rare lesions, and less than 20 descriptions of these lesions outside the middle fossa have been reported. In this report, we describe a dural cavernous angioma involving the posterior sagittal sinus and discuss the clinical, radiological, operative, and histological features of this very uncommon lesion. Case Description: A 31-year-old right-handed male presented with headache and decreasing visual acuity. Severe bilateral papilledema was found on fundoscopic examination. Neurological examination demonstrated a minor right temporal field cut. Brain magnetic resonance imaging with contrast demonstrated a 2.5 2.5 cm hyperintense enhancing mass in the midline, which was contiguous with the posterior margin of the falx cerebri. The patient underwent a bilateral occipital craniotomy centered on the lesion. The histological features were consistent with cavernous angioma. Conclusion: This report demonstrates that although extra axial cavernomas are quite rare, they must be included in the differential diagnosis of enhancing lesions along the posterior sagittal sinus. The operative removal of these lesions can be quite treacherous and usually requires a careful reapproximation of the patent sinus after lesion excision. D 2005 Elsevier Inc. All rights reserved.
Cavernous angioma; Sagittal sinus; Extraaxial
2. Case report
Between 5% and 13% of cerebral vascular malformations  are cavernous angiomas or cavernous hemangiomas (cavernomas). Although these lesions may occur anywhere in the brain or spinal cord, extraaxial cavernous angiomas are very rare lesions. The vast majority of these dural cavernous angiomas are found in the middle fossa, and less than 20 cases of dural cavernous angiomas outside the middle fossa have been reported . In this report, we describe a dural cavernous angioma involving the posterior sagittal sinus and discuss the clinical, radiological, and histological features of this lesion.
2.1. Clinical presentation
* Corresponding author. Tel.: +1 215 662 3487; fax: +1 215 349 5534. E-mail address: [email protected]
(J.A. Boockvar). 0090-3019/$ – see front matter D 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.surneu.2004.03.012
A 31-year-old right-handed male presented with several years of history of headache and 6 months of history of decreasing visual acuity particularly when reading small letters. The patient denied any history of ataxia, hearing loss, seizure, nausea, or vomiting. Severe bilateral papilledema was found on fundoscopic examination. Neurological examination demonstrated a minor right temporal field cut. 2.2. Radiographic findings Brain magnetic resonance imaging (MRI) (Fig. 1A: sagittal 1B: coronal 1C: axial) with contrast demonstrated a 2.5 2.5 cm hyperintense enhancing mass in the midline and was contiguous with the posterior margin of the falx cerebri. There was remodeling of the adjacent bone. A small cavernous angioma in the cerebellar vermis and a pineal
J.A. Boockvar et al. / Surgical Neurology 63 (2005) 178 –181
2.3. Operation The patient underwent a prone, frameless, stereotaxyguided bilateral occipital craniotomy centered on the lesion. A 2.5 2.5 cm lesion was found in the midline and within the superior sagittal sinus (Fig. 3A). The overlying bone had been significantly eroded (Fig. 3B). The dura was initially opened in a C-shaped fashion lateral to the midline (Fig. 3C). This confirmed that the lesion was entirely intradural. Thiopental was administered, and the dura of the superior sagittal sinus opened immediately over the lesion in the midline. Gross examination of the lesion showed a brownish gray lesion consistent with aged hemorrhage. The lesion arose from or was attached to a leaflet of dura of the superior sagittal sinus. Vigorous sinus anterograde and retrograde bleeding was encountered when the superior and inferior poles of the lesion were mobilized. However, by leaving the lesion in situ, it acted as a ball valve to stop bleeding. The entire dissection was completed with the lesion in situ. Before removing the mass, interrupted 4.0 neurolon sutures were placed. The lesion was then removed en bloc; the sinus appeared patent and was flushed with heparinized saline while the preinserted sutures were secured to reconstitute the sinus. The suture line was reinforced with a pericranial graft. No brain swelling was observed during surgery. 2.3.1. Pathological findings Histological examination demonstrated an intricate network of irregularly shaped vascular spaces surrounded by loose to focally dense sclerotic fibrous tissue (Fig. 4). Several vessels were thrombosed. Recent hemorrhage with extravasation of red blood cells and accumulation of hemosiderin-laden macrophages, indicative of old hemorrhage with chronic inflammation, was prominent throughout the lesion. The vascular lumina varied widely
Fig. 1. a to c, Brain MRI (a, sagittal; b, coronal; c, axial) with contrast demonstrating a 2.5 2.5 cm hyperintense midline enhancing mass contiguous with the posterior margin of the falx cerebri. A pineal region cyst (white arrowhead) was also seen.
region cyst were also observed. Two-dimensional phase contrast magnetic resonance venograph and cerebral angiography (Fig. 2) demonstrated that the mass was immediately above the torcula and that it significantly attenuated the superior sagittal sinus. The sinus, however, appeared to be patent.
Fig. 2. Lateral internal carotid artery angiography demonstrating an avascular mass immediately above the torcula. The superior sagittal sinus was significantly attenuated (open arrow) but appears to be patent.
J.A. Boockvar et al. / Surgical Neurology 63 (2005) 178 –181
Fig. 4. Histological photomicrograph (hematoxylin and eosin, original magnification 10 ) showing an intricate network of irregularly shaped vascular spaces (black arrow) surrounded by loose to focally dense sclerotic fibrous tissue. Extravasation of red blood cells and accumulation of hemosiderin-laden macrophages are prominent throughout the lesion.
in size and were lined by inconspicuous endothelium. No well-formed elastic lamina was identified with special stains (Fig. 5). Similarly, no brain parenchyma was identified within lesional tissue. The histological features were felt to be consistent with cavernous angioma. 2.3.2. Postoperative course An MRI obtained 1 day after surgery confirmed a gross total resection. Although attenuated, the superior sagittal sinus and both transverse sinuses were patent. The patient tolerated the procedure well and reported improvement in his headache. Four weeks after surgery, fundoscopic examination demonstrated less severe papilledema. There was improvement in his visual fields but no objective change in his visual acuity.
Fig. 3. Intraoperative photograph (a) demonstrating a 2.5 2.5 cm lesion within the superior sagittal sinus above the torcula (white arrow). b, The overlying bone has been significantly remodeled. c, The dura over the sinus was reapproximated to reconstitute the sinus. The initial C-shaped opening to inspect intradurally is on the left (asterisk), and the sinus repair is midline (open arrow).
Fig. 5. Histological photomicrograph (elastic stain, original magnification 20 ) demonstrating the vascular structure of the lesion. The vascular lumina varied widely in size and were lined by inconspicuous endothelium. No elastic lamina was identified (asterisk).
J.A. Boockvar et al. / Surgical Neurology 63 (2005) 178 –181
3. Discussion Cavernous angiomas involving the dura mater exclusively are extremely rare lesions . We were able to identify only one previous case in the literature describing a posterior sagittal sinus cavernoma . In this report, we describe another case of a cavernous angioma arising from within the posterior sagittal sinus just above the torcula. Lesions in the posterior superior sagittal sinus may become symptomatic by sinus compression [1,2]. This may result in headache, venous hypertension, and papilledema, such as in this patient. Spontaneous hemorrhage as a clinical presentation is exceedingly rare in dural cavernous angiomas . Radiographically, the lesion described in this report showed typical features of an extraaxial cavernoma, although lesions such as a meningioma were considered in the differential diagnosis. For example, computed tomography and MRI demonstrated a strongly and homogenously enhancing lesion that looked consistent with a meningioma [3,6]. However, catheter angiography demonstrated no vascular blush suggesting alternative diagnoses, such as a cavernoma, that are typically not seen on conventional angiography. The exact mechanism of how dural cavernomas grow is unclear . Parenchymal cavernomas are thought to grow by recurrent hemorrhages . In contrast, dural cavernous angiomas may grow but rarely do they show evidence of prior hemorrhage. Mechanisms other than hemorrhage may be responsible for growth and may include capillary budding, hormonal factors, ectasia, or thrombosis of vascular spaces . Dural cavernous angiomas, particularly those located outside the middle fossa, can usually be easily removed and clinical outcome is often excellent . We were able to successfully resect and then reconstruct the superior sagittal sinus. This was associated with improvement in venous hypertension and papilledema. References  Biondi A, Clemenceau S, Dormont D, Deladoeuille M, Ricciardi GK, Mokhtari K, Sichez JP, Marsault C. Intracranial extra-axial cavernous (HEM) angiomas: tumors or vascular malformations? J Neuroradiol 2002;29(2):91 - 104.  Kaga A, Isono M, Mori T, Kusakabe T, Okada Y, Hori S. Cavernous angioma of falx cerebri: case report. No Shinkei Geka 1991;19(11): 1079 - 83.  Lewis AI, Tew J, Payner TD, Yeh H. Dural cavernous angiomas outside the middle cranial fossa: a report of two cases. Neurosurgery 1994;35(3):498.  Maruishi M, Shima T, Okada Y, Nishida M, Yamane K, Okita S. Cavernous sinus cavernoma treated with radiation therapy—case report. Neurol Med Chir (Tokyo) 1994;34(11):773 - 83.  Meyer FB, Lombardi D, Scheithauer B, Nichols DA. Extra-axial cavernous hemangiomas involving the dural sinuses. J Neurosurg 1990;73(2):187 - 92.
 Vogler R, Castillo M. Dural cavernous angioma: MR features. AJNR Am J Neuroradiol 1995;16:773 - 5.
Commentary The authors have reported a case of an extraaxial cavernous angioma that involved the posterior one third of the superior sagittal sinus. This is an unusual entity of which practicing neurosurgeons should be made aware. The patient in this case report presented with symptoms of venous outflow obstruction including symptomology and neuroophthalmologic findings consistent with increased intracranial pressure. The patient was found to have an enhancing mass lesion in the midline compressing and stenosing the posterior one third of the superior sagittal sinus and ultimately underwent open surgical resection of this lesion. This lesion was confirmed on micropathology to be consistent with extraaxial cavernous hemangioma. As far as the surgical management is concerned, it is unclear why the surgical team required frameless stereotaxy guidance to resect this mass lesion, when the location and the extent of the mass was readily apparent on the imaging studies. In addition, we have found that CT scanning with bone windows is helpful in determining the extent of bony involvement and for planning adequate bony exposure. We agree with the surgical plan of resecting this lesion in the prone position due to the possibility of air embolization through the superior sagittal sinus, if this lesion were resected in the sitting position, which we would not advocate in this case. The readership would be well advised not to underestimate the magnitude of blood flow that can be coursing through the posterior one third of the sagittal sinus, and we would recommend a wide bony exposure to obtain vascular control of the proximal and distal portion of the involved sinus. We would advocate generous opening of the dura adjacent to the sagittal sinus proximal and distal to the mass to facilitate temporary vascular occlusion of the superior sagittal sinus, if necessary during the procedure, should hemorrhaging occur. Problems with adequate sinus reconstruction during removal of midline lesions are mostly abated with clear visualization afforded by proximal and distal temporary sinus occlusions and a hemostatic surgical field. This typically affords rapid and expedient sinus reconstruction and minimizes the effects of venous engorgement due to temporary occlusion of the posterior one third of the sagittal sinus. Thomas Kopitnik, MD Duke Samson, MD Department of Neurosurgery UT Southwestern Medical Center Dallas, TX 75235, USA