A case of head and neck cutaneous squamous cell carcinoma highlighting aggressive perineural features.

Cutaneous squamous cell carcinoma (cSCC) is the second most common nonmelanoma skin cancer in the United States following basal cell carcinoma. The majority are successfully cured by surgical excision or Mohs microsurgery. A subset of cSCCs are more aggressive and likely to recur locally, spread to regional lymph nodes or even distantly, and can even result in death. High-risk features of cSCC including perineural invasion of nerve >0.1 mm in diameter and invasion beyond the subcutaneous fat are not routinely reported by Mohs microsurgery. Facial cSCC commonly involves branches of the facial nerve (VII) or trigeminal nerve (V). Clinical symptoms associated with cranial nerve VII and V involvement include pain, paresthesia of the face and tongue, facial paralysis. Assessment of nerve involvement by magnetic resonance imaging (MRI) is the most optimal imaging modality. Here, we present a case where Mohs microsurgery was performed on a facial cSCC 1.5 years prior to the development of facial paresis. We aim to highlight the interesting perineural path resulting in facial paralysis and associated symptomatology, the importance of MRI, and to remind clinicians of important high-risk features of cSCC.