Perineurial Invasion of the Facial Nerve: A Case Report with Extension from Cutaneous Squamous Cell Carcinoma

Abstract

A case report is presented of an unusual occurrence of peripheral facial nerve paresis owing to isolated perineurial extension from a cutaneous squamous cell carcinoma. Current evidence dispels the previously held belief that perineural invasion and extension occurs in lymphatic spaces. The clinical importance of recognizing this route of spread by tumors of the head and neck is discussed.

Perineural Invasion of Cutaneous Malignancies

“…The remaining group suffers from sensory or motor complaints and may have a poorer prognosis 8,9,22,29,30 . Involved nerves often appear normal on gross inspection because axial spread typically surpasses concentric growth 31–33 . Early PNI confined to small nerves in the reticular dermis is rarely suspected until demonstrated histologically 19 .…”

“…Intravenous administration of gadolinium diethylenetriamine pentaacetic acid (Gd‐DTPA) enhances the visualization of affected nerves, allowing the course of the nerve to be traced through the foramina and into the brainstem 33,51 . Unfortunately negative radiographic findings are of little value in the diagnostic process, as many patients with neurologic symptoms have no radiographic evidence of nerve involvement 17,52 …”

“…Clinical symptoms and the demonstration of gross tumor extensions by radiology or surgery particularly indicate a poor prognosis. The prognosis is improved, however, if tumor spread is limited to extracranial nerve segments 9,52 . At this stage, long‐term outcome can be good if eradication of the tumor is attained with the use of aggressive surgical and possibly adjunctive therapy such that tumor cells are prevented from extending along minor nerve endings to involve larger trunks 17,19,53 .…”

Perineural Invasion of Cutaneous Malignancies

“…8,9,22,29,30 Involved nerves often appear normal on gross inspection because axial spread typically surpasses concentric growth. [31][32][33] Early PNI confined to small nerves in the reticular dermis is rarely suspected until demonstrated histologically. 19 Indeed, there are reports of tumors remaining asymptomatic in the perineural space until recurrence up to two decades after primary resection.…”

Cranial Neuropathy as a Presenting Sign of Recurrent Aggressive Skin Cancer

“…In a series of 160 patients diagnosed with Bell's palsy, May and Lucent 22 reported a single patient with symptoms secondary to perineural invasion follow-ing 2 years of progressive weakness of the facial nerve. Strauss and Cohen23 reported the case of a 58year-old woman with a 5-month history of progressive facial pain as the presentation of recurrence in a previously excised squamous cell carcinoma of the cheek. Mark24 reported two cases of basal cell carcinoma with perineural invasion presenting with trigeminal neuralgia and localized neuralgia at the sites of tumor recurrence.…”