Skull Base Surgery
The skull base is an extremely complex anatomical region in which an enormous variety of pathological entities may be encountered. These include congenital, inflammatory, and vascular lesions, as well as benign and malignant neoplasms. Surgery of the skull base is technically challenging, and many lesions were previously deemed inoperable due to the close proximity of many vital neural and vascular structures. Though there can be e variety of tumors arising from the skull base, the most common tumors are Vestibular Schwannomas, Meningiomas, Paragangliomas and Petrous bone cholesteatomas.
A paraganglioma is rare neuroendocrine neoplasm that may develop at various body sites (including the head, neck, thorax and abdomen). About 97% are benign and cured by surgical removal. Paragangliomas are still sometimes called glomus tumors and chemodectomas, but paraganglioma is the currently accepted and preferred term. There are three types in the head & neck – Glomus tympanicum and Glomus jugulare, Carotid paraganglioma (carotid body tumor) & Vagal paragangliomas.
A vestibular schwannoma, often called an acoustic neuroma, is a benign primary intracranial tumor of the myelin-forming cells of thevestibulocochlear nerve (CN VIII). The term “vestibular schwannoma” involves the vestibular portion of the 8th cranial nerve. Vestibular schwannomas usually develop gradually over a period of years; most often, it may not come up with any obvious symptoms in the earlier stages. but later on present with sensorineural hearing loss/deafness, disturbed sense of balance and vertigo.
Meningiomas are a diverse set of tumors arising from the meninges, the membranous layers surrounding the central nervous system. These tumors are usually benign in nature and many meningiomas are asymptomatic, producing no symptoms throughout a person’s life, but larger tumors can cause symptoms depending on the size and location.
Petrous bone cholesteatomas
Petrous bone cholesteatoma describes an epidermoid cyst affecting the petrous portion of the temporal bone. It extends beyond the inner ear towards the center of the skull base. Clinical presentation of petrous bone cholesteatoma is not only variable but may be misleading. It can present as a middle ear cholesteatoma, progressive or sudden facial nerve palsy, sensorineural hearing loss or a conductive hearing loss, secretary otitis media or intracranial complication.