Sclerosing Cavernous Hemangioma in the Cavernous Sinus: Case Report

ABSTRACT

Cavernous hemangiomas of the cavernous sinus belong to a well–distinguished entity of extra–axial cavernous hemangiomas located in the cavernous sinus and have a typical appearance on magnetic resonance imaging (MRI). Severe intraoperative bleeding has been described during the excision of these lesions that is probably associated with their pathological features. An atypical case of a sclerosing lesion with distinct MRI features is described. In these particular cases, especially with giant hemangiomas where en bloc excision would be difficult, safe internal decompression and resection can be achieved.

Intracranial dural–based cavernous hemangiomas are rare benign vascular lesions. They arise from the dural sinuses, mostly from the cavernous sinus where they represent 0.4 to 2 % of the lesions.¹ They are well demarcated but expansive. Their clinical course is aggressive and usually involves the neurovascular components of the cavernous sinus.² There is a clear female preference, and the mean age of presentation is around the fifth decade.³

Most authors recommend en bloc removal with interruption of the arterial feeders because biopsy or piecemeal removal can produce massive bleeding. Piecemeal removal can be difficult with deep–seated lesions, especially with the large and giant cavernous hemangiomas.^{3, 4, 5}

We present a patient with a less–vascularized cavernous hemangioma in the cavernous sinus with distinct MRI and pathological features. Intraoperative findings and pathological features suggest that a distinct subgroup of less–vascularized tumors can be identified.

CASE REPORT

A 64–year–old, right–handed woman had a 5–year history of left–sided trigeminal neuralgia affecting the second and third divisions of the trigeminal nerve. She obtained partial relief with carbamazepine (800 mg a day). She was neurologically intact, including ocular movements and her facial sensory and corneal reflexes. Computerized tomography (CT) showed a right parasellar 5–cm isodense lesion associated with calcifications and erosion of the ipsilateral petrous bone (Fig. 1). Because she was allergic to iodine, the contrast phase of the examination was not performed. Magnetic resonance imaging (MRI) showed a well–demarcated lesion that was hypointense on T1–weighted sequences and irregularly hyperintense on T2–weighted sequences (Fig. 2). The lesion was intensely enhanced but inhomogeneous with the administration of gadolinium. The lesion occupied the cavernous sinus and extended to the sphenoid sinus and petroclival region where it compressed the pons. A small contiguous intra–axial portion that was hypointense on T1–weighted sequences without contrast enhancement in the septal area and paraterminal gyrus was probably ischemic. Magnetic resonance angiography (MRA) showed discrete stenosis of the ipsilateral petrous internal carotid artery (ICA) with inferior and medial displacement of the petrous and cavernous segments of the artery (Fig. 3). She refused ICA angiography and a balloon occlusion test.

Figure 1A.

CT scan without contrast showing an isodense mass with calcifications and erosion of the petrous apex.

Figure 2A.

Axial T1–weightedpreoperative MRI, showing a mass with inhomogeneous gadolinium enhancement and inhomogeneous hyperintense signal on T2–weighted sequences.

Figure 3.

Magnetic resonance angiogram showing discrete stenosis of the right petrous carotid artery, with inferior and medial displacement of the petrous and cavernous segments of the ICA (arrows) as well as superior displacement of the ipsilateral M1 segment.

The patient was submitted to a right cranio–orbitozygomatic approach with initial extradural exposure of the anterior and middle fossae and dissection of the proximal portion of the petrous ICA. After the extradural steps of the cavernous sinus exposure were performed as described by Dolenc and Al–Mefty,^{6, 7} the dura mater was opened in a semicircular fashion. The Sylvian fissure was dissected extensively. After the veins of the temporal tip were divided, the temporal lobe was mobilized posteriorly.

The dura of the lateral wall of the cavernous sinus was peeled from the pseudocapsule of the tumor. The tumor was firm, fibrous, and nonpulsatile, quite different from the typical intraoperative features of cavernous sinus hemangiomas. Dissection from the surrounding structures, including the cranial nerves in the cavernous sinus and ICA, and an en bloc resection could not be performed safely in this giant tumor. However, internal decompression and piecemeal resection were accomplished with minimal intraoperative bleeding. The pseudocapsule of the lesion was then dissected in a radical fashion from the nerves at the cavernous sinus wall, from the ICA, and from the arachnoid of the posterior fossa over the pons.

The postoperative period was uneventful. Function of the involved cranial nerves was preserved. Postoperative MRI confirmed the radical resection but showed a small residual piece of tumor in the medial wall of the cavernous sinus, which had not been noted during surgery (Fig. 4).

Figure 4.

Postoperative coronal T1–weighted MRI with gadolinium infusion showing radical resection of the tumor and a very small residual lesion medial to the ICA on the medial wall of the cavernous sinus.

During 16 months of follow–up, the patient had no apparent recurrence. However, her contralateral trigeminal neuralgia, her unique preoperative complaint, was unrelieved, and she still requires medical treatment to control the symptoms.

Histological sections showed that the specimen consisted of abundant hyaline, dense connective tissue involving vascular channels of various calibers (Fig. 5A). The connective tissue was in calcified areas or showed foci of bony metaplasia (Fig. 5B). Aggregates of hemosiderin pigment indicated previous hemorrhage. The appearance was that of a sclerosing cavernous hemangioma with calcification and ossification.

Figure 5A.

Photomicrographs showing prominent hyaline dense connective tissue and sparse vascular channels of varied caliber.

Figure 5B.

Photomicrographs showing prominent hyaline dense connective tissue and sparse vascular channels of areas of bony metaplasia.

DISCUSSION

Dural–based cavernous hemangiomas of the cavernous sinus are hypervascular extra–axial lesions well known for being extremely difficult to remove because of severe intraoperative bleeding. The perioperative rate of mortality related to uncontrollable bleeding has been reported as high as 12.5 %.¹

The usual presentation includes oculomotor deficits related to involvement of the lateral cavernous sinus wall. The duration of symptoms varies from weeks to 10 years.^{3, 8}

The present patient had no ocular symptoms. She had an unusual clinical picture of contralateral trigeminal neuralgia, which was thought to be caused by brainstem distortion. Cavernous sinus hemangiomas seldom calcify and tend to erode adjacent bony structures. This patient had prominent foci of calcifications in the lesion as seen on noncontrasted CT. Subsequent MRI showed a well–demarcated lesion that was hypointense on T1–weighted sequences, with intense but inhomogeneous enhancement, and irregularly hyperintense on T2–weighted images.

Cavernous hemangiomas usually grow toward the middle fossa and sellar regions, encasing neurovascular structures in the same way as other tumors in this region.^{9, 10, 11, 12} On MRI, neurilemomas and meningiomas may have similar appearance that cannot be reliably distinguished preoperatively from cavernous sinus hemangiomas.^{13, 14} A marked homogeneous hyperintensity on T2–weighted images, which was not consistent with the MRI findings in our patient, is the typical finding from cavernous hemangiomas of the cavernous sinus.^{3, 8, 14}

Shi and associates³ divided cavernous hemangiomas within the cavernous sinus into two subgroups based on histopathological and operative findings. Subtype A depicted soft, very vascular, and pulsating lesions, associated with severe bleeding. Histopathological studies of this group show thin–walled vascular channels and scanty connective tissue. Intraoperative findings from subtype B showed firmer lesions without visible pulsations, and histopathological studies showed solid parenchyma, well–formed vessels, and ample connective tissue. Shi et al³ concluded that subtype B cavernomas contain more parenchyma and had a greater likelihood of being resected completely. They found no correlation on the basis of preoperative MRI and CT that could reliably predict the operative course of these lesions.³ Our case is consistent with the less–vascular subtype B.

Proliferation of the connective tissue between the vascular spaces and calcification would be part of the natural history of cavernous hemangiomas. Fibrosis is probably part of the evolution of some hemangiomas and would represent a regressive phenomenon.

The gold standard for the microsurgical resection of brain tumors, especially for giant tumors, is internal decompression followed by dissection. Potential exceptions are solid hemangioblastomas and cavernous sinus hemangiomas because they are hypervascular and bleed excessively during surgery. One–piece removal without incision of the pseudocapsule is ideal for hemangiomas of the cavernous sinus but may be impossible with large lesions.¹ However, if neural structures surrounding a large cavernoma must be preserved, piecemeal resection should be considered. In such cases, induced hypotension and injection of a plastic adhesive have been advocated to decrease intraoperative bleeding.^{1, 15}

Postoperative radiotherapy has been used with cavernous sinus hemangiomas, mainly in residual lesions, with a few good outcomes.^{14, 16, 17} However, conclusive evidence is lacking regarding the benefit of radiosurgery for surgical remnants or small cavernous hemangiomas in the cavernous sinus.^{3, 8, 18}

CONCLUSION

En bloc resection is advised for dural–based cavernous hemangiomas to avoid significant blood loss. It is possible that a subtype of cavernous hemangiomas with a less aggressive clinical picture can be identified preoperatively by inhomogeneous enhancement on MRI, irregular high T2–weighted signal intensity, and calcifications on CT. Patients harboring these massive lesions can safely undergo internal decompression and piecemeal resection without the risk of life–threatening intraoperative bleeding.

Figure 1B.

CT scan bone window.

Figure 2B.

T2–weighted preoperative MRI, showing a mass with inhomogeneous gadolinium enhancement and inhomogeneous hyperintense signal on T2–weighted sequences.

Figure 2C.

Coronal T1–weighted MRI showing the large mass with inhomogeneous enhancement after administration of gadolinium.