Perineural spread of skin cancer presenting as diplopia

A direct transcutaneous approach to infraorbital nerve biopsy

Purpose: To describe a novel transcutaneous infraorbital nerve biopsy technique which can be performed to aid in the diagnosis of perineural invasion (PNI) of facial cutaneous squamous cell carcinoma (SCC).Methods: A single-center retrospective chart review was performed. Patients diagnosed with SCC with PNI via an infraorbital nerve biopsy between February 2019 and February 2020 were included. Data collected consisted of patient demographics, medical history, clinical presentation and exam, histologic and radiographic findings, treatment, and outcomes.Results: Four patients (3 male, 1 female) met inclusion criteria. The mean age at diagnosis was 79.5 years (range 66-85 years). Three of the four patients had a history of facial skin lesions, including actinic keratosis and SCC, involving the nose, cheek, or ear. One patient had no history of cutaneous malignancy. All patients presented with cranial neuropathies, including total V2 hypoesthesia. The most common presenting symptom was facial pain, followed by diplopia, unilateral facial weakness, and hypoesthesia in the V1 and/or V2 distribution. Transcutaneous infraorbital nerve biopsy in all patients revealed squamous cell carcinoma with no biopsy complications.Conclusion: Definitive diagnosis of PNI can be challenging but is important to minimize tumor-related morbidity. Infraorbital nerve biopsy can establish this diagnosis, especially in the context of negative or indeterminate imaging findings. This work comprises the first description of a transcutaneous approach to infraorbital nerve biopsy, which is a minimally invasive technique that can be performed in an outpatient procedure suite with limited to no sedation.