[Diagnostic imaging and differential diagnosis of pathological processes of the sinus cavernosus]

Spectrum of Surgically Resected Lesions of the Cavernous Sinus: A Neuropathologic Audit

Background  The cavernous sinus is a complex space composed of extradural venous plexus within dural folds. Several important structures like the carotid artery, cranial nerves, and sympathetic nerve fibers traverse through this space. Radiological diagnosis may not be definitive and in the context of discordance between clinical and neuroimaging diagnosis, histopathological evaluation becomes essential for diagnosis and management. Literature on the pathological spectrum of lesions is scarce as, with a shift in the treatment paradigm, most small lesions of cavernous sinus are treated with radiosurgery. However, surgical management still plays a role for larger lesions and in radiologically ambiguous cases for planning the definitive management.

Materials and Methods  We retrospectively reviewed all surgically resected lesions of the cavernous sinus over the last two decades (1998–2019). The clinical presentation, neuroimaging features, and histopathological findings were reviewed. Lesions extending from sella and other adjacent areas were excluded.

Results  Thirty-eight cases of isolated cavernous sinus mass lesions were diagnosed over the last two decades (1998–2019). Cavernous hemangiomas (19 cases, 50%) constituted the most frequent pathology, followed by aspergilloma, meningioma, schwannoma, metastatic adenocarcinoma, chondrosarcoma, and chordoma. Overall, 29.4% (10/34) could not be accurately diagnosed on neuroimaging. Of these, four cases of cavernous hemangiomas were mistaken for either meningioma (three cases) or schwannoma (one case). Neither chordoma nor chondrosarcoma was suspected.

Conclusion  This is the first study in literature, enumerating the pathological and imaging spectrum of surgically resected cavernous sinus lesions. Cavernous hemangiomas, metastases and chordomas, and chondrosarcoma posed the greatest difficulty in diagnosis on neuroimaging and the reasons for the same are analyzed. In the context of clinical and neuroimaging discordance in diagnosis, pathological characterization becomes essential for appropriate and timely management.

Endovascular treatment of a direct post-traumatic carotid-cavernous fistula with electrolytically detachable coils

Carotid-cavernous fistulae are abnormal communications between the internal carotid artery and venous compartments of the cavernous sinus. Fistulae are uncommon but well-documented sequelae of craniofacial trauma. The characteristic clinical presentation includes ocular pain, chemosis, exophthalmus and visual disturbances. We report on a 28-year-old man with a history of severe craniocerebral injury, including multiple craniofacial fractures resulting from a fall from a height of approximately 6 meters, who was surgically treated one year ago. Two months before presentation, the patient began to exhibit progressive chemosis, proptosis, eyelid swelling, diplopia and exophthalmus. Computerized tomography and computerized tomographic angiography revealed findings consistent with a carotid-cavernous fistula of the right side of the cavernous sinus with dilatation of the right ocular vein. Digital subtractional angiography of the right internal carotid artery revealed a fistula between the cavernous part of the artery and the right cavernous sinus. There was only minimal blood flow in the supraclinoid part of the internal carotid artery because of the high pressure within the fistula. Our decision was to try to occlude the fistula by means of endovascular embolization. The origin of the fistula in the internal carotid artery was successfully obliterated with seven electolytically detachable coils. Control digital subtractional angiography at the end of the procedure demonstrated minimal residual flow through the fistula. Two months after the treatment, angiographic control revealed complete obliteration of the fistula. Clinical examination showed total resolution of signs and symptoms of a carotid-cavernous fistula. Endovascular transarterial embolization of carotid cavernous fistulae is a widely accepted, safe and successful treatment option. In the case that we describe we occluded the fistula and right cavernous sinus with electrolytically detachable coils that we could place into the sinus. Other endovascular treatment options include the use of detachable balloons, stent placement, transvenous embolization or surgical ligation of the fistula.