Cutaneous Head and Neck Malignancies With Perineural Spread to Contralateral Cranial Nerves: An Argument for Extending Postoperative Radiotherapy Volume

Abstract

IntroductionThe incidence of nonmelanoma cutaneous head and neck malignancies is increasing worldwide.1 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%. 2,3 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. 4 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. Case ReportsWithin a cohort of 55 patients who were treated from 1996 to 2011 with confirmed PNS from a cutaneous malignancy, six patients with ipsilateral cranial nerve PNS and subsequent contralateral PNS were identified. Patient demographic and clinical characteristics were reviewed and are summarized in Table 1. Ethics approval was obtained from our institution's Human Research Ethics Committee.Case Example. A 49-year-old woman (Table 1, patient 4) presented with a 3-month history of increasing swelling and pain in the left cheek. Twelve years before, the patient had sustained a blast/burn injury to the left hemiface, and 18 months before presentation, had a squamous cell carcinoma (SCC) on the left side of the nose excised with adjuvant radiotherapy. A computed tomography scan indicated recurrence of the lesion, with bony erosion of the inferior orbit and anterior maxillary wall and extension into the antrum. A magnetic resonance imaging (MRI) scan showed involvement of V2 at the foramen rotundum to the anterior aspect of Meckel's cave. Surgery involved en bloc removal of the left cheek skin, lateral nose wall, orbit floor, periorbita, and the infraorbital nerve to the gasserian ganglion. Reconstruction was performed with radial artery forearm flap and split skin graft. Histopathology confirmed SCC with PNS of left V2 to the anterior aspect of Meckel's cave. The patient received postoperative radiotherapy to the operative bed, as previously described, back to the gasserian ganglion, using a total dose of 60 Gy in 30 fractions. The cutaneous branches of V2 (with some extension into V3 cutaneous distribution) were treated, but only the proximal part of V3. This was delivered by a mix of electrons and three-dimensional conformal photon radiotherapy. Five years after surgery, the patient developed paresthesia, formication, and pain in the right cheek. An MRI scan showed abnormal thickening and enhancement that were consistent with PNS along the intra-and extracranial segments of right V2 and V3. The patient refused additional treatment and died as a result of her contralateral disease 13 months after detection. DiscussionThe trigeminal (V) and facial (VII) nerves are the most common cranial nerves to be affected by PNS, 5 and disease may prog...

Orbital, Ocular, and Optic Nerve Tumors

“…167 If surgery is not feasible because of associated functional and cosmetic problems, treatment with radiation has been successful for patients with either histologic type. 80,173,174 Similar results have been observed in more recent series using high-dose-rate brachytherapy and surface molds (99% local control among primary tumors and 87% for recurrent lesions).…”

“…Another report of patients with squamous cell cancer demonstrated a recurrence rate of 3% at 5 years following Mohs's surgery. 80,173,174 Clinically apparent perineural invasion or grossly involved nerves may prompt consideration of coverage of the infraorbital nerve as well as the trigeminal ganglion. [168][169][170] In more than 1000 patients with eyelid tumors treated with radiation, Fitzpatrick et al 171 noted a 5-year local control rate of 95% and 93% in basal cell and squamous cell carcinoma primary cancers, respectively.…”

Postoperative Imaging and Surveillance in Large Nerve Perineural Spread

“…There is also the potential for spread of perineural tumor across the midline peripherally because of crossover anastomoses that occur between cutaneous branches of the nerves. 19 Central failure occurs when there is ongoing perineural spread along the involved nerve toward the brainstem. In this case, there is enhancement and thickening of the involved nerve that progresses on follow-up imaging (►Fig.…”

Cranial Nerves

“…Table 4 identifi es primary tumor sites in the head and neck and the associated cranial nerves at risk for perineural spread. Direct extension to PTF Nasopharynx (Chang et al 2005 ;Lu et al 2001 ) V and VI (less common II, III, IV, XII) Direct extension to Meckel's cave, cavernous sinus, and carotid space Nose (Barnett et al 2013 ) V (Table 5 ) 6 Cases…”