Nerve Sheath Myxoma: An Immunohistochemical Study of a Case

W. Jurecka, MD, Second Department of Dermatology, University of Vienna, Alserstrasse 4. A-1090 Vienna, (Austria) Sir I read with great interest the article ‘Nerve Sheath Myxoma’ by Nogita et al. [1]. Clinically this case fits very well in the series of hitherto described cases where the age of onset in general seems to be in youth or early adolescence, where most patients suffer from solitary tumors of variable size and where signs of Recklinghausen’s disease are rare or absent [2]. The origin of this type of tumor from Schwann cells or perineural cells was always a matter of debate. However, to judge from a majority of S-100 protein positive cells for a Schwann cell origin is not justified. It could be demonstrated by morphological methods that this tumor type, in contrast to other tumors of the peripheral nervous system, contains a high percentage of perineural cells [2, 3]. This is indicating that in this tumor type besides Schwann cells also perineural cells are involved in tumor growth. In larger peripheral nerves, tumors showing mainly endoneural growth together with mucoid transformation are called plexiform neurofibroma. The parallel structural findings in both tumor types lead to the proposition of the name plexiform neurofibroma of the skin for the tumor type debated here. References Nogita T, Someya T, Nakagawa H, Otsuka F, Ishibashi Y: Nerve sheath myxoma: An immunological study of a case. Dermatologica 1990;191:317-319. Jurecka W: Plexiform neurofibroma of the skin. Am J Dermatopathol 1988;10:209-217. Jurecka W: Neurogenic tumors of the skin. Wien Klin Wochenschr 1987(suppl 176).