Cutaneous epithelioid melanocytic neurofibroma arising in a patient with neurofibromatosis-1
Article first published online: 26 FEB 2014
© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd
Journal of Cutaneous Pathology
Volume 41, Issue 5, pages 457–461, May 2014
How to Cite
Cutaneous epithelioid melanocytic neurofibroma arising in a patient with neurofibromatosis-1., , , .
- Issue published online: 24 APR 2014
- Article first published online: 26 FEB 2014
- Accepted manuscript online: 28 JAN 2014 12:42PM EST
- Manuscript Revised: 25 JAN 2014
- Manuscript Accepted: 25 JAN 2014
- Manuscript Received: 19 NOV 2013
- melanocytic lesions;
- neural crest
Tumors expressing both melanocytic and neural features can pose a diagnostic challenge to the dermatopathologist and provoke questions regarding their lineage. We report a case of a tumor arising on the right cheek of a 9-year-old boy with neurofibromatosis type 1 (NF-1). This neoplasm featured nests of non-pigmented epithelioid cells arising within a neurofibroma. The entire tumor stained strongly with S100, whereas the epithelioid population stained with MART-1, HMB-45 and MiTF. The neoplasm shows only scattered Ki-67 positivity. This tumor represents a neurofibroma with portions that have undergone melanocytic differentiation (melanocytic neurofibroma). This exceedingly rare tumor represents a distinct entity from neurotized melanocytic nevi, combined melanocytic nevi or pigmented neurofibromas and provides further evidence that melanocytes arise indirectly from ventromedial neural crest-derived Schwann cell precursors.