S2k Guideline – Merkel cell carcinoma (MCC, neuroendocrine carcinoma of the skin) – Update 2022

• DOI: 10.1111/ddg.14930
• Publication Date: 2023-03-17T05:56:12Z
• Authors: Jürgen C. Becker; Ambros J. Beer; Viola K. DeTemple; Thomas Eigentler; Michael Flaig; Thilo Gambichler; Stephan Grabbe; Ulrike Höller; Bernhard Klumpp; Stephan Lang; Claudia Pföhler; Christian Posch; Vikas Prasad; Peter Schlattmann; Sylke Schneider‐B...; Jan Ter‐Nedden; Patrick Terheyden; Kai Thoms; Dirk Vordermark; Selma Ugurel
• Keywords: Guideline; Neuroendocrine carcinoma; Merkel cell

Summary Merkel cell carcinoma (MCC, ICD‐O M8247/3) is a rare, malignant, primary skin tumor with epithelial and neuroendocrine differentiation. The cells share many morphologic, immunohistochemical, ultrastructural features cutaneous cells. Nevertheless, the of origin MCC unclear. appears clinically as reddish to purple spherical smooth, shiny surface soft turgid, elastic consistency, usually showing rapid growth. Spontaneous often complete regressions are observed. These likely immunologically‐mediated explain cases in which only lymph node or distant metastases found at time initial diagnosis why responds very well immunomodulatory therapies even advanced stages. Due its aggressiveness, given indication for sentinel biopsy, adjuvant be evaluated, complexity necessary diagnostics, clinical management should already determined by an interdisciplinary board diagnosis.