Endonasal Surgery of Anterior Skull Base Malignancies: Principles and Long-Term Results

Introduction: The aim of the present study was to establish the efficacy of endonasal microendoscopic surgery for removal of benign and malignant neoplastic lesions of the paranasal sinuses and the anterior skull base.

Material and Methods: This retrospective study evaluated 350 patients with tumors of the paranasal sinuses and the anterior skull base (215 benign and 135 malignant tumors) that were treated surgically at the ENT-Department of the Hospital Fulda gAG between 1993 and 2003. Median follow-up was 65 months.

Results: The most frequent entities of benign tumors were osteomas, inverted papillomas, and juvenile angiofibromas. Adenocarcinomas, squamous cell carcinomas, and esthesioneuroblastomas were most frequently treated in the group of malignomas. Fifty-four percent of the benign and 41% of the malignant tumors were resected exclusively via the endonasal microendoscopic approach. Within the follow-up period, 3 recurrences were observed, two inverted papillomas (one was operated endonasally) and one juvenile angiofibroma. In the malignoma group the 5-year survival rate was 66.4% with respect to the disease-specific survival. The Kaplan-Meier analysis revealed statistically significant differences for the pT stage: pT2 and pT3 tumors have had a 5-year disease-specific survival of 92.3% and 83.8%, respectively, compared with 61.5% of the pT4 tumors. Disease-specific survival showed also differences dependent on histology, tumor site, and occurrence, but was without proven significancy. After endonasal resection, 5-year disease-specific survival was 78.4% in the patient group suffering from adenocarcinoma, squamous cell carcinoma, or esthesioneuroblastoma compared with 66.4% in patients operated via an external approach.

Conclusions: The advances in endonasal microendoscopic surgery allow also a safe and effective removal of benign and malignant anterior skull base tumors with low morbidity. Indication is dependent on tumor site and size as well as histology.