RESUMO
Mature teratoma is the most common germ cell tumor [and the most common tumor] of the ovary, composing more than 20% of all ovarian neoplasms. Super infection of dermoid ovarian cyst is very rare. A 72 years-old woman admitted to the gynecological outpatient clinic because of lower abdominal pain and fever. Gynecological examination and ultrasonography revealed a heterogeneous cystic mass in the right ovary. Abdominopelvic CT scan revealed a right ovarian mass [15 x 15cm] thought to be a dermoid cyst. Right adnexectomy was performed. The pathological evaluation suggested infected benign ovarian dermoid. Infection of a mature teratoma is a relatively uncommon event. However, based on our case and others, superinfection with abscess formation should be considered in the differential diagnosis whenever a patient with a documented pelvic mass and fever