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.
Suster
S
S
Department of Pathology and Laboratory Medicine, Mount Sinai Medical Center, Miami Beach, Florida.
Amazon
K
K
Rosen
L B
LB
Ollague
J M
JM
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