1Department of Obstetrics and Gynecology, S. Orsola-Malpighi Hospital, via Massarenti 13, 40138 Bologna, Italy
2Department of Pathology, Central Hospital, Bolzano, Italy
3Department of Gynecology Oncology, European Institute of Oncology, Milano, Italy
4Department of Pathology, S. Orsola-Malpighi Hospital, Bologna, Italy
5Department of Clinical and Experimental Medicine, Section of Microbiology, University of Bologna, Bologna, Italy
6Department of Oral Pathology, Institute of Dentistry, University of Turku, Finland
7Department of Oncology and Radiotherapy, Turku University Hospital, Turku, Finland