[Merkel cell tumor of the skin].
A skin tumor of a 66-year-old female was examined morphologically and immunohistochemically in relation to its histogenetic aspect. The tumor was located within the dermis and composed of compact round cells with scanty cytoplasm. Electron-microscopic study revealed the presence of dense-cored granules within the cytoplasm. Thus the tumor was thought to derive from Merkel cells. The tumor cells were positive for keratin and negative for S-100 protein by immunohistochemistry. Therefore, we posit that the tumor cells did probably not originate from the neural crest, but rather from epidermal immature cells.
D000230:Adenocarcinoma / Q000473:pathology* / Q000648:ultrastructure; D000368:Aged; D003594:Cytoplasmic Granules / Q000648:ultrastructure; D005260:Female; D006801:Humans; D012878:Skin Neoplasms / Q000473:pathology* / Q000648:ultrastructure