Studies On Clinical And Biological Behaviors And Anatomic Comparative Surgical Approaches Of Median Skull Base Tumor

Median skull base, located in the center of skull base, is a highly complex region adjacent multiple bony foramina through which pass several important neurovascular structures. The superior limit of its anterior border is sella turcica and posterior border is the anterior edge of great occipital foramen, the lateral ambit is between the line of optic canal and lateral tangents of the foramen magnum. The inferior anterior- posterior limit is between the anterior skull base and anterior edge of foramen magnum, the lateral limit is between the medial pterygoid plates and lateral tangents of the foramen magnum.The pathology of median skull base tumor, most of which are benign or low-grade malignant tumors, is complex. Either skull base chordoma or juvenile nasopharyngeal angioma (JNA) is the representative tumor originated from the bone and/or periosteum of the median skull base. Median skull base corresponds to intracranial region of the brain stem, pituitary gland and adjacent several cranial nerves, ICA and cavernous sinus and extracranial structures include the sphenoid sinus and nasopharynx. The radical resection of median skull base tumor is remains to be a challenging due to its vital site and most of the tumors are not sensitive to radiotherapy and chemotherapy.This study aims to explore the pathological characteristics of skull base chordoma and JNA at the median skull base, which is benign and low-grade malignant, but clinically behaves highly malignant. The study consists of clinical, pathological, biological and anatomic studies on median skull base in the following three parts:Part One: Clinical StudySixty-one patients with skull base chordoma includes 34 males and 27 females and the average age was 38.44 ?3.61. Superior approaches were performed 48 times, and inferior approaches 42 times for 61 patients. We first advocated the staging system for skull base chordoma into stage I , IK ILL IV for sellar and clivus type and stage IVfor extensive type. The important goal of staging for skull base chordoma is to help chose surgical approaches, prognosis evaluation and comparing different treatments. The 3,5,10 and 15 years survival rate is 72.80%> 60.22%, 31.16% and 13.67% respectively. The factors that influenced the patient's survival rate include hoarseness, tumor rigidity and clinical stage. The skull base chordoma with obvious nasopharyngeal and nasal cavity involvements was specially discussed. Fourteen patients with juvenile nasopharyngeal angiofibroma, which had cranial or cavernous sinus involvements, were studied; the age was 10-39(averaged 16.95). There were 24 times approaches for 14 patients and the total patients were followed up for at least two years. There were 3 patients with recurrence and the recurrence rate was 21.4%. The combined intracranial and extracranial approach for advanced JNA resection was advocated.Part Two: Pathologic and Biological Study.The well-organized pathologic study for skull base tumor, JNA and olfactory neuroblastoma was carried out. We found that high-density chordoma cells, mixed fibrous and mucous stroma and necrosis region in the tumor tissue were the three malignant-related symbols for skull base chordoma. Significant correlation between extensive tumor growth in JNA and high-density stromal cell was noticed.Nine tumor markers were detected with tissue chip technology and immunochemistry for skull base chordoma and JNA. The olfactory neuroblastoma was designed for the malignant control tissue. The results showed that CK, Vimentin was 100% positive in skull base chordoma vs. 100% negative in skullbase chondrosarcoma. Strong positive expression of P-cadherin , TGF-13 and VEGF was associated with bad prognosis and strong positive expression of S-100,Vimentin was associated with good prognosis of skull base chordoma. Positive correlation was found between strong positive expression of P-cadherin > VEGF> EMA> Cathepsin D and bad prognosis, and strong positive expression of S-100^ Vimentin and nm23 between good prognosis for skull ba...