Malignant epithelioid schwannoma of the skin. A low-grade neurotropic malignant melanoma?
We studied a polypoid cutaneous neoplasm excised from the left arm of a 23-year-old man by light microscopy, immunohistochemistry, and electron microscopy. Histologically, the tumor was composed of a proliferation of round to oval epithelioid cells that were arranged in fascicles and showed a prominent perineural distribution. Immunohistochemistry revealed the presence of S-100 protein and vimentin within tumor cells. Electron microscopy demonstrated reduplication of basal lamina and abundant long-spacing collagen in intercellular spaces. The findings are consistent with a primary malignant epithelioid schwannoma of the skin. We discuss the relationship of this lesion with other neoplasms in the spectrum of tumors showing schwannian and melanocytic lines of differentiation.
Department of Pathology and Laboratory Medicine, Mount Sinai Medical Center, Miami Beach, Florida.
S
S
Suster
K
K
Amazon
L B
LB
Rosen
J M
JM
Ollague
D000328:Adult; D003937:Diagnosis, Differential; D006801:Humans; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000473:pathology / Q000648:ultrastructure; D009442:Neurilemmoma / Q000175:diagnosis* / Q000473:pathology / Q000648:ultrastructure; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000648:ultrastructure