[1] Med Univ Prof Dr Paraskev Stoyanov, Univ Hosp St Anna, Dept Gynaecol, Varna, Bulgaria
[2] St Ivan Rilski Univ Hosp, Pathol Lab, Sofia, Bulgaria
[3] Nadezhda Hosp, Histopathol Lab, Sofia, Bulgaria
[4] Univ Hosp St Marina Pleven, Med Univ Pleven, Pleven, Bulgaria
[5] Univ Hosp St Anna, Dept Gynaecol, Varna, Bulgaria
[6] Med Univ Pleven, Dept Gynaecol Oncol, Pleven, Bulgaria