caa a22 4500 606241337 CHVBK 20210128101312.0 cr unu---uuuuu 210128e20150501xx s 000 0 eng 10.1007/s00508-014-0660-z doi (NATIONALLICENCE)springer-10.1007/s00508-014-0660-z Merkel cell carcinoma of the lower leg with retroperitoneal GIST: a very rare association [Elektronische Daten] [Uwe Wollina, Gesina Hansel, Felicitas Zimmermann, Jacqueline Schönlebe, Andreas Nowak] Merkelzellkarzinom des Unterschenkels und retroperitenaler GIST - eine sehr seltene Assoziation Summary: Merkel cell carcinoma (MCC) is a rare neuroendocrine tumor of the skin. Although its association with other malignancies is well known, an association with gastrointestinal stromal tumor (GIST) has yet not been described. We report about a 65-year-old female patient who presented with a hypervascularized subcutaneous tumor mass of her left calf. Resection of the primary tumor and histopathological investigations confirmed the diagnosis of MCC. The patient was treated by delayed Mohs surgery, and tumor-free margins were obtained. Sentinel lymph node biopsy was negative for metastatic spread. Primary tumor and lymph node basin were treated by adjuvant radiotherapy. During staging of the patient, a second malignancy—a GIST—was detected. Neoadjuvant treatment with multikinase inhibitor imatinib induced a partial response of GIST that was eventually removed by surgery. However, 8 months later, the patient developed subcutaneous regional metastases of MCC, which were surgically removed. Adjuvant therapy was planned by oncologists. To the best of our knowledge, the occurrence of MCC and GIST in the same patient has yet not been reported. In contrast to GIST, MCC did not respond to imatinib, although c-kit mutations are common in MCC. Springer-Verlag Wien, 2014 Merkel cell carcinoma nationallicence Gastrointestinal stromal tumor nationallicence Multikinase inhibitor nationallicence Sentinel lymph node biopsy nationallicence Second malignancy nationallicence Merkelzellkarzinom nationallicence Gastrointestinaler Stromatumor nationallicence Multikinaseinhibitor nationallicence Sentinellymphknotenbiopsie nationallicence Zweittumor nationallicence Wollina Uwe Department of Dermatology and Allergology, Academic Teaching Hospital Dresden-Friedrichstadt, Friedrichstrasse 41, 01067, Dresden, Germany aut Hansel Gesina Department of Dermatology and Allergology, Academic Teaching Hospital Dresden-Friedrichstadt, Friedrichstrasse 41, 01067, Dresden, Germany aut Zimmermann Felicitas Department of Vascular Surgery, Academic Teaching Hospital Dresden-Friedrichstadt, Friedrichstrasse 41, 01067, Dresden, Germany aut Schönlebe Jacqueline Institute of Pathology "Georg Schmorl”, Academic Teaching Hospital Dresden-Friedrichstadt, Friedrichstrasse 41, 01067, Dresden, Germany aut Nowak Andreas Department of Anesthesiology and Intensive Care Medicine, Emergency Medicine and Pain Management, Academic Teaching Hospital Dresden-Friedrichstadt, Friedrichstrasse 41, 01067, Dresden, Germany aut Wiener klinische Wochenschrift Springer Vienna 127/9-10(2015-05-01), 402-405 0043-5325 127:9-10<402 2015 127 508 https://doi.org/10.1007/s00508-014-0660-z text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00508-014-0660-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wollina Uwe Department of Dermatology and Allergology, Academic Teaching Hospital Dresden-Friedrichstadt, Friedrichstrasse 41, 01067, Dresden, Germany aut NATIONALLICENCE 700 1- Hansel Gesina Department of Dermatology and Allergology, Academic Teaching Hospital Dresden-Friedrichstadt, Friedrichstrasse 41, 01067, Dresden, Germany aut NATIONALLICENCE 700 1- Zimmermann Felicitas Department of Vascular Surgery, Academic Teaching Hospital Dresden-Friedrichstadt, Friedrichstrasse 41, 01067, Dresden, Germany aut NATIONALLICENCE 700 1- Schönlebe Jacqueline Institute of Pathology "Georg Schmorl”, Academic Teaching Hospital Dresden-Friedrichstadt, Friedrichstrasse 41, 01067, Dresden, Germany aut NATIONALLICENCE 700 1- Nowak Andreas Department of Anesthesiology and Intensive Care Medicine, Emergency Medicine and Pain Management, Academic Teaching Hospital Dresden-Friedrichstadt, Friedrichstrasse 41, 01067, Dresden, Germany aut NATIONALLICENCE 773 0- Wiener klinische Wochenschrift Springer Vienna 127/9-10(2015-05-01), 402-405 0043-5325 127:9-10<402 2015 127 508