1. Department of Obstetrics and Gynecology, Bern University Hospital and University of Bern, 3010 Bern, Switzerland
2. Department of Gynecology and Obstetrics, Ente Ospedaliero Cantonale of Lugano, 6900 Lugano, Switzerland
3. Facoltà di Scienze Biomediche, Università della Svizzera Italiana, 6900 Lugano, Switzerland
4. Department of Gynecology and Obstetrics, Bürgerspital Solothurn, 4500 Solothurn, Switzerland
5. Institute of Pathology, Universitätsklinikum Düsseldorf, 40225 Düsseldorf, Germany
6. Institute of Tissue Medicine and Pathology, University of Bern, 3008 Bern, Switzerland