Ovarian dermoid cysts are made up of solid, cystic and fat tissue. These components give rise to characteristic sonographic features such as a fat-fluid level, dermoid mesh and tip of the iceberg sign. The presence of two or more of these typical features can be used to confidently diagnose a dermoid cyst on ultrasound. This 41-year-old woman with a known cystic lesion on her right ovary which, on ultrasound, demonstrated two of these features, had the diagnosis of a dermoid cyst later confirmed on histopathology. She concurrently had an elevated serum human chorionic gonadotrophin (hCG), an unusual, but not unknown, finding in the presence of a dermoid cyst. The hCG resolved after removal of the ovarian cyst.
Keywords: Dermoid; human chorionic gonadatrophin; mature teratoma; ovarian cyst; transvaginal ultrasound.