Diagnosis And Microsurgery Of Rare Tumor In Cavernous Sinus

Objective：Meningioma, neurilemmoma and cavernous hemangioma are commontumors located in cavernous sinus. As epidermoid cyst, chordoid meningioma and adenoidcystic carcinoma are relatively rare, there were few reports of the clinical diagnosis andtreatment. Based on our experience of successful resection of these uncommon tumors incavernous sinus and knowledge from associated literatures, we want to improve theaccuracy of preoperative diagnosis and resection rate of these lesions by optional surgicalapproaches.Methods：The clinical data of epidermoid cyst, chordoid meningioma and adenoidcystic carcinoma of cavernous sinus operated successfully in our department were analysedretrospectively as well as the literatures from Medline. The features of meningioma,neurilemmoma, cavernous hemangioma, epidermoid cyst, chordoid meningioma andadenoid cystic carcinoma were compared according to manifestation, imaging andpathology. The advantages and disadvantages of different surgical approaches were linedout based on the comparison of associated anatomy, intraoperative procedure andpostoperative complicationsResults：There are no obvious specificity of manifestations between cavernous sinusarea tumors, the dysfunction of III～VI cranial nerves are major symptoms. The symptomsand signs are often caused by primary lesions of adenoid cystic carcinomas due to theinvasion from extracranial to intracranial cavity. As the initial symptoms, the nervousstimulation and dysfunction are common in neurilemmoma, who arised from Schwanncells.According to MRI imaging, relative uniform enhanced signal is often occurred inmeningiomas, while none uniform enhancing in chordoid meningiomas as well asundefinition in neurilemmoma. Variant size of cysts can be found in adenoid cysticcarcinomas with none uniform enhancement. Epidermoid cyst presents as characteristichigh signal in diffuse weighted serial without enhancing. Cavernous hemangioma shows obviously high signal in T2weighted image, enhanced scan presents more high signal incomparison to meningiomas.Similar pathological features can be found between meningioma and chordoidmeningioma, and the expression of D2-40protein of chordoid meningioma is positive aswell as negative in meningioma. The expression of S-100and Leu-7, as well as GFAPpartly, are positive in neurilemmoma, who is composed of spindle cells or small stellatecells with variant degenerations. VEGF related receptors increased in expression ofcavernous hemangioma, who composed by blood sinus. Epidermoid cysts are nodule orcyst in shape under surgical fields with calcified and slimy contents. The crumbyproliferation of tumor cells arrayed in cribriform and adeniform is characteristic signshistologically of adenoid cystic carcinoma.Tumors located in cavernous sinus can be removed via pterional or modified pterionalapproaches. The fronto-orbito-zygomatic approach is fit for lesions involving orbital cavityas well as subtemporal transzygomatic approach for mass of posterior cavernous sinus.Most lesions in cavernous sinus can be resected via subtemporal keyhole approach.Conclusion：1. The clinical symptoms are often atypical with the cavernous sinussyndrome as their major symptom.2. Though the enhanced MRI is helpful to discriminatevariant tumors located in cavernous sinus, the crucial diagnosis is based on pathology.3.Majority of lesions in cavernous sinus can be removed via subtemporal keyhole approach.