Nevus Cells of Nerve Sheath Origin?-Reply

In Reply.—  We would like to thank Cramer for his comments regarding our recent article. His observation of epithelial membrane antigen expression by spindle-shaped cells in the deep dermal component of nevi is interesting. We would agree that these cells most likely represent perineurial cells, or cells showing perineurial differentiation. While epithelial membrane antigen is recognized as a marker of epithelium, its expression by a number of nonepithelial cell types has been reported, including neoplastic and nonneoplastic perineurial cells,¹ plasma cells,² meninges,³ notochord,⁴ and the tumor cells of synovial sarcoma,⁵ epithelioid sarcoma,⁵ leiomyosarcoma,⁶ lymphoma,² meningioma,³ and chordoma.⁴It is interesting that tumor cells of neurofibromas and schwannomas have been reported to be negative for epithelial membrane antigen.¹ In a report by Ariza et al,¹ expression of epithelial membrane antigen by neurofibromas was confined to compressed cells located at the periphery