Cutaneous head and neck malignancies with perineural spread to contralateral cranial nerves: an argument for extending postoperative radiotherapy volume.

Introduction The incidence of nonmelanoma cutaneous head and neck malignancies is increasing worldwide. In a small percentage of cases, associated perineural spread (PNS) of cranial nerves occurs, resulting in poor prognosis, with a recorded 5-year survival rate of 50% to 64.3%. Patients with clinical PNS from cutaneous head and neck malignancies are treated with surgical resection and postoperative radiotherapy. Recent literature provides few reports of PNS that extends across the facial midline to affect the contralateral cranial nerves. This report describes patients with ipsilateral cranial nerve PNS that has subsequently progressed to contralateral cranial nerves, to both highlight and address the potential implications for the postoperative radiotherapy volume.