Extragonadal omental teratoma: a case report.

Mature cystic teratomas or dermoid cysts are among the most common ovarian tumors; however, teratomas of extragonadal origin are extremely rare. The most common extragonadal site of these teratomas is the omentum. It is generally accepted that teratomas arise from germ cells that originate in the mature gonads. Of the three proposed causes of omental teratoma, auto-amputation and subsequent re-implantation of gonadal teratoma is the most likely preceding event. A review of the published reports reveals that only 31 cases of teratoma of the greater omentum have been published to date and three cases reported wherein omental teratoma and dermoid of the ovary were coexisting. We report a rare case of an omental teratoma in a 26-year-old woman who underwent ovarian cystectomy for dermoid cyst. This is the fourth case of an omental mature teratoma with coexisting ovarian dermoid cyst.