[Neuroendocrine (Merkel cell) skin cancer. Electron microscopic study]

The study is concerned with the results of light and electron microscopic examination of 2 cases of neuroendocrine (Merkel cell) carcinoma of the skin. Both patients developed multiple widely-distributed intra- and subcutaneous nodules. Histologically, tumors were mostly trabecular. Electron microscopic examination revealed neuroendocrine secretory granules, small bundles of intermediate fibers, a well-defined Golgi complex and a relatively high level of vesicular structures. There were some basal membrane fragments. It is suggested that they originate from polypotential epithelial stem cells.