The ultrasound demonstrated bilateral adnexal multilobular predominantly cystic masses with multiple mural nodules of widely varying architecture and echogenicity. Both lesions exhibited areas of posterior shadowing and areas of clustered punctate high amplitued echos characteristic of hair embedded in sebum, typical of the dermoid.
Cystic Teratomas or Dermoids account for 10% to 15% of all ovarian tumors and are bilateral in 10% of the cases. They are composed of mature epithelial elements: a combination of skin, hair, sebum, desquamated epithelium, and teeth.
Dermoids are relatively soft masses and on physical examination may be difficult to palpate and are frequently either missed or underestimated in size. If large, a dermoid may torse, and then present as acute abdominal pain. They are rarely malignant.
Dermoids range in size and echogenicity. Depending on the extent and admixture of their epithelial elements, the ultrasound patterns can vary markedly, even within a single mass. There are, however some typical patterns. The two “classic” dermoid appearances are the “tip of the iceberg” sign, caused by absorption of most of ultrasound beam at the top of the mass (because of multiple internal interfaces) and “dermoid plug” sign, which has the appearance of one or more hyperechoic areas within a hypoechoic mass.
Another less commonly seen , but more specific, dermoid appearance is identification of interlacing linear and punctuate echoes corresponding to crossing strands of hair within the mass.
Occasionally, a dense calcification corresponding to a completely formed or rudimentary tooth is seen and can be confirmed to be a tooth by a pelvic radiograph or a CT scan.
Rarely, a lipid-fluid level can be identified within the mass and the fluid level may shift position when the patient moves.
Very rarely, dermoids can be completely anechoic. This pattern is encountered most commonly in adolescence.