Perineural Spread of Melanoma: Lessons Learned the Hard Way

Abstract

Extension of tumor cells along the perineural environment is referred to as perineural spread. Amongst the head and neck malignancies, nonmelanoma cutaneous or non-cutaneous cancers such as squamous cell carcinoma, adenoid cystic carcinoma and lymphoma are the more common malignancies known to spread perineurally. Melanoma especially the rare desmoplastic subtype has a propensi-ty to spread along cranial nerves. We present two cases of metastatic melanoma with perineural spread, in the absence of a concurrent cutaneous lesion, resulting in a delayed diagnosis. In this retrospective case series, we highlight the factors that complicate timely accurate diagnosis. Detailed medical and surgical history, clinically appropriate differential diagnosis, sensitive imaging modalities, and experience of the interpreting neuroradiologist all play crucial role in the clinical investigation and reaching a timely and accurate diagnosis.