title: Neuroendocrine carcinoma of the skin (Merkel cell carcinoma): ultrastructural and immunohistochemical demonstration of neurofilaments.
abstract: In this study we characterized a skin tumor that grew in the temporal region of a 69-year-old woman. On the basis of tumor morphology, a metastasis from a small cell carcinoma of the lung was initially suggested, but X-ray and bronchoscopic studies were negative. The tumor recurred twice within a year, yet no tumors were found elsewhere in the body. Ultrastructurally, cytoplasmic organelles compatible with neuroendocrine storage granules and perinuclear aggregates of intermediate-sized (8-10 nm) filaments were found in many tumor cells. Indirect immunofluorescence microscopy revealed neurofilament-type intermediate filaments in the tumor cells but no keratin- or vimentin-type filaments. Our results further demonstrate neural properties of this tumor type, which is generally considered to have its origin from Merkel cells, the cutaneous neuroendocrine cells.
mesh_terms: D000368:Aged; D002277:Carcinoma / Q000473:pathology / Q000648:ultrastructure*; D003599:Cytoskeleton / Q000648:ultrastructure*; D005455:Fluorescent Antibody Technique; D006801:Humans; D008297:Male; D008854:Microscopy, Electron; D012878:Skin Neoplasms / Q000473:pathology / Q000648:ultrastructure*