Surgical Approaches to Pre-Auricular Cutaneous Squamous Cell Carcinomas Extending to the Temporal Bone.

Abstract

Standardized surgical approaches to advanced pre-auricular cutaneous squamous cell carcinomas (cSCC) are lacking. Fifty-four patients who underwent lateral temporal bone resection (LTBR) for pre-auricular cSCC were grouped into "Levels" of increasing disease spread. Surgical approaches to achieve negative-margin resection were designed for each Level and replicated on cadaveric specimens. Level 1 extended to the external auditory canal, requiring LTBR ± superficial parotidectomy. Level 2 involved the retromandibular space ± temporomandibular joint, necessitating partial mandibulectomy, in addition to the above. Level 3 and 4 involved the deep parotid, being situated either away from (> 5 mm) or close (≤ 5 mm) to the anterior carotid sheath (ACS), respectively. These tumors require radical parotidectomy, with incorporation of the ACS for Level 4. Level 5 involved the ACS at the skull base and should be treated non-surgically. This Level-based system will hopefully lead to further prospective studies and improvements in outcomes for advanced pre-auricular cSCC.