Explain how an abscess may develop with PID. Solution Answer: The most common complication of PID is formation of abscess in ovary, also known as Tubo-ovarian abscess.The formation of abscess in ovary begin with the pathogens spreading from cervix to the endometrium into the peritoneal cavity and forming the tubo-ovarian abscess.Sperm also act as important vehicle for transport of pathogens such as Chlamydia trachomatis and Neisseria gonorrhoeae into the fallopian tubes.As bacteria enter the ovary, the immune system sends white blood cells to fight the infection. This causes inflammation at the site of infection and cavity is created filled with pus to form an abscess..