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Cutaneous epithelioid melanocytic neurofibroma arising in a patient with neurofibromatosis‐1
Author(s) -
Novoa Roberto A.,
Kovarik Carrie L.,
Low David W.,
Argenyi Zsolt
Publication year - 2014
Publication title -
journal of cutaneous pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.597
H-Index - 75
eISSN - 1600-0560
pISSN - 0303-6987
DOI - 10.1111/cup.12297
Subject(s) - neurofibroma , neurofibromatosis , pathology , neural crest , melanocytic nevus , nevus , epithelioid cell , medicine , dermatology , melanoma , biology , immunohistochemistry , cancer research , embryo , microbiology and biotechnology
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.