Epithelial sheath neuroma: be aware of benign perineural invasion!

Perineural involvement by epithelial cells is usually considered as a sign of malignancy and is seen in a variety of malignant skin neoplasms. However, there are other benign conditions characterized by the presence of perineural involvement by epithelial cells. We present a case of epithelial sheath neuroma in a 43-year-old male. The clinicopathological features of this newly described entity are discussed together with the differential diagnosis and the different hypotheses of pathogenesis. Both pathologists and dermatologists should be aware of this entity to avoid misdiagnosis of malignancy.