[Merkel cell tumor (neuroendocrine carcinoma of the skin) in an unusual location. Immunohistochemical and lectin histochemical findings]. / Ungewöhnlich lokalisierter Merkelzelltumor (Neuroendokrines Karzinom der Haut). Immunohistochemische und lektinhistochemische Befunde.

Neuroendocrine carcinoma of the skin usually occurs in elderly individuals. Head and neck are the most common primary sites followed by the extremities and trunk. As this tumor represents a remarkable rarity in younger people, we report the case of a 33-year-old woman with a neuroendocrine carcinoma in an unusual localization. Diagnosis was based on the results of the examination of a metastasis in the inguinal lymph nodes. The lesion at the Labium minus pudendi which is to be considered the primary tumor was detected several months later. Diagnosis of Merkel cell tumor until recently had depended on ultrastructural demonstration of dense-core membrane-bound granules. Today, diagnosis can be secured also by optical light microscopy, on the basis of a certain constellation of immunohistochemical and lectin histochemical findings.