Parasitic omental ovarian dermoid tumour mimicking an adnexal mass: A report of two very unusual cases.

The differential diagnosis of cystic adnexal masses includes various pathologies, some placed extragonadally. Herein, we present two different cases of omental ovarian dermoid tumours that were diagnosed using ultrasonography and removed with surgery. The greater part of the omental teratomas appear to have developed from self-amputation of cysts in the ovary, followed by their re-implantation into the omentum. Omental teratomas can be located in the pelvis, where they might be mistaken for an adnexal mass, an upper abdominal mass, or a periumbilical mass. The location of omental teratomas might slightly change from one examination to another. In such cases, preoperative diagnostic imaging methods may not provide adequate information to physicians. Gynecologists should always keep in mind the possibility of intraabdominal ovarian parasitic cystic teratomas in the differential diagnosis of suspicious adnexal masses during surgery. Awareness among gynecologic surgeons of such masses may help prevent misdiagnosis, delayed surgery, or the use of wrong surgical approaches.