ABSTRACT

There are many different tumors of the peripheral nerves that can be found in and around the nail organ. This chapter describes the types of the neurogenic tumors, including benign neurogenic tumors and malignant neurogenic and neuroendocrine tumors. It also describes the histopathology and differential diagnosis of some of the benign neurogenic tumors, including neuroma, rudimentary supernumerary finger, pacinian neuroma, neurofibroma, schwannoma, cellular neurothekeoma, nerve sheath myxoma, granular cell tumor and perineurioma. The chapter explains the histopathology and differential diagnosis of some of the malignant neurogenic and neuroendocrine tumors, including Merkel cell carcinoma, Ewing sarcoma, malignant schwannoma and malignant granular cell tumor. Granular cell tumor of the nail was observed as a verrucous periungual growth in the deep medial portion of the proximal nail fold of a big toe causing a longitudinal depression in the nail or as an enlargement of the middle toe overgrowing the nail.