The cavernous sinus is a very complex area, and surgical treatment requires detailed anatomical knowledge and familiarity with its relationship to surrounding structures. By exposing the lateral wall of the cavernous sinus with the extradural approach, it is possible to pass through the triangular corridor of the cavernous sinus and perform surgical treatment for diseases such as trigeminal schwannoma and meningioma inside and outside the cavernous sinus. In addition to the extradural infratemporal fossa approach, the extradural infratemporal fossa to the pterygoid fossa and the approach to the paranasal sinuses can be safely performed by inserting the endoscope into the bone corridor of the middle cranial fossa. Furthermore, in the last decade, transnasal endoscopic skull based approaches have further developed, facilitating surgical access to the cavernous sinus. The cavernous sinus is an unattachable site due to the complex structure of multiple nerves, veins, and internal carotid arteries, but if the anatomy of the cavernous sinus is known well we can treat this complex site. As for the choice of approach to the cavernous sinus, a better understanding of the anatomy surrounding the cavernous sinus will allow a rational choice between transcranial and transnasal approaches.
Pituitary adenomas are one of the most common brain tumors. They represent approximately 18% of all intracranial, and around 95% of sellar neoplasms. In recent years, our understanding of the pathophysiology and the behavior of these lesions has led to better control and higher curative rates. The treatment decision is largely dependent on type of the adenoma, clinical presentation, and the size of the lesion. In addition, incidental pituitary lesions add uncertainty in the decision-making process, especially for pituitary adenomas that can be medically managed. When surgery is indicated, the endoscopic endonasal transsphenoidal approach is the technique of choice, but open standard craniotomy approaches can also be the option in selected cases. The following chapter will review the classification, clinical presentation, pathophysiology, diagnostic work-up, selection of surgical approach, and treatment complications in pituitary adenomas.
Extended orbital exenteration is a highly disfiguring operation which entails complete removal of the orbital contents including periorbita, eyelids and involved surrounding bony walls with variations tailored to the specific clinical circumstances. The aim of such an extensive surgery is to achieve local control of the life-threatening progressive neoplasms, when other treatment modalities fail to achieve disease control. Eyelids can be preserved in posterior orbital pathology, while it may not be possible in neoplasms arising from the anterior eye tissues. Depending on the clinical circumstances, if the neoplasm is invading the surrounding bony orbit, the involved bony and soft tissue structures are removed en bloc to achieve complete resection (R0 resection). Although the steps of the orbital exenteration are well defined, the same is not true for extended orbital exenteration. We demonstrate the details of extended orbital exenteration in different clinical scenarios for the malignancy of orbit and periorbital tissues invading surrounding orbital walls.
Chordoma is a rare bone malignancy that influences the spine and cranium base. Once in a while, it includes bone and when it does, cranial bones are the favored location. Chordomas emerge from embryonic remnants of the primitive notochord and chondrosarcomas from primitive mesenchymal cells, otherwise from the embryonic rest of the cranial cartilaginous matrix. Chondrosarcomas constitute a heterogeneous group of essential bone malignancy characterized by hyaline cartilaginous neoplastic tissue. Both are characterized by invasion and pulverization of the neighboring bone and delicate tissue with higher locoregional reappearance frequency. Chordoma and chondrosarcoma, especially myxoid variation of chondrosarcoma of the cranium base, are as often as possible amalgamated because of similar anatomic location, clinical presentation, and radiologic sightings, and mixed up histopathological highlights. Chordoma and chondrosarcoma vary with respect to their origin, management strategy, and contrast particularly with respect to outcome. Ultimately, developing indication supports aberrant growth factor signaling as possible pathogenic mechanisms in chordoma. Here, we have shown such a location-based symptomatic predicament, understood effectively with ancillary immunohistochemistry. In this review, we summarize the most recent research findings and focus primarily on the pathophysiology and diagnostic aspects.
Benign skull base tumors include meningiomas, pituitary adenomas, craniopharyngiomas, and vestibular schwannomas. As an adjuvant therapy to surgery or when surgical treatment carries too high a risk of complications, a highly precise focused radiation, known as stereotactic radiosurgery or fractionated stereotactic radiation therapy, can be delivered to the tumor. The aim of this chapter is to systematically discuss benefits of the therapy, i.e., tumor control as well as complications and risk factors of the therapy relating to vision, hearing, hormone secreting regions, and cerebral vasculature. Meningiomas, pituitary adenomas, craniopharyngiomas, and vestibular schwannomas constitute the majority of primary skull base tumors amenable to stereotactic radiation therapy or radiosurgery and will be described in this chapter.
