[Merkel cell cancer].

The authors analyze 3 cases of Merkel-cell carcinoma, examined by light and electron microscopy with the use of the immunomorphologic method. The diagnosis of this type of carcinoma is based largely on microscopic examination of the tumor. The principal morphologic sign is the presence of relatively monomorphous cells characterized by a definite growth pattern; trabeculae, strands, separated by connective tissue laminae. Electron microscopy ranks second in informative value; it detects the endocrine granules, provided the number of the examined samples is sufficient. Immunomorphologic detection of cytokeratins confirms only the epithelial nature of the tumor.