The contribution of oncological lateral skull base surgery to the management of advanced head-neck tumors

Background: Lateral skull base is a complex area between the brain and the neck that is characterized by a large anatomic variability in narrow spaces and wide heterogeneity of tissues. The complexity of the anatomy makes it more difficult to accurately identify tumor spread and surgical planning is here particularly demanding. Aims: Oncological skull base surgery is conceived for malignant lesions originating in, secondarily infiltrating, or in close proximity to the lateral skull base. It is also conceived for selected aggressive or benign lesions of the parapharyngeal space and infratemporal fossa abutting the skull base, or crossing it from above downwards to the neck. This paper is focused on the role that oncological skull base surgery plays to resect tumors in this area. Methods and results: Three main types of head and neck lesions can be identified as paradigms of the philosophy of oncological lateral skull base surgery, and are herein presented: (i) primary malignant tumors of the ear; (ii) advanced malignant parotid tumors; (iii) primary malignant or locally aggressive tumors of the infratemporal fossa-parapharyngeal space. The en-bloc lateral and subtotal temporal bone resections, the en-bloc temporo-parotid resection and the combined subtemporal-transcervical-transparotid resection are described, respectively. Conclusions and significance: Different histologies are found in the lateral skull base and adjacent areas, and each histology has its own pattern of growth and undetected spreading in a difficult-to-reach surgical area. The leading principle is to create a wide access through soft tissues and bone removal far enough from the tumor to obtain a complete resection, en-bloc radical resection in malignancies. The entity of dissection is obviously modulated on the tumor triad (histology, pattern of growth, extent) and is achieved through the en-bloc and combined approaches that are here described.