Arianna Acrivoulis, from Bari, died in an operating theatre at Florenzo Jaja hospital on Wednesday, Ansa reported.
She had been undergoing a fine-needle aspiration in the ovary, a procedure by which cells are extracted to be examined.
“We are devastated. This should not have happened,” her sister Alessandra, told Ansa.
Bari prosecutors are investigating two doctors for manslaughter, while police have seized the patient's medical file.
The head of the enquiry tribunal in Bari, Luciana Silvestris, is arranging an autopsy.
By Louise Naudé