[Merkel cell carcinoma (trabecular carcinoma) of the skin].

The Merkel cell carcinoma was first designated some years ago by the descriptive term trabecular carcinoma. Both names refer to a skin tumor occurring in elderly patients. This is another example where ultrastructural differentiating criteria are necessary for a definite diagnosis i.e., identification of so-called neurosecretory-like granules by electron microscopy. We report clinical, histological, ultrastructural, and histogenetic aspects of such a disease in a woman suffering from a metastasizing Merkel cell carcinoma.