1st April 2022

A 66-year-old lady complains of pelvic pain and abdominal distension

A 66-year-old lady complains of pelvic pain and abdominal distension for the past six months. She has no known gynaecological history and had her menopause at age 55. Her mother has a history of breast cancer. Physical examination found abdominal distension, with a left adnexal mass that was firm, immobile and non-tender.

Select the SINGLE most definitive investigation from the list below. Select ONE option only.