Professional and Linguistic Assessments Board (PLAB) Practice Exam

What does the tip of the iceberg sign on imaging suggest?

1. Fibroids

2. Dermoid cyst

3. Endometriosis

4. Ovarian reserve

The correct answer is: Dermoid cyst

The tip of the iceberg sign on imaging, particularly in relation to ovarian masses, suggests the presence of a dermoid cyst, also known as a mature teratoma. This sign is characterized by a cystic lesion that appears predominantly anechoic on ultrasound but has echogenic components located beneath that represent the various tissues often found within a dermoid cyst, such as hair, fat, and sometimes teeth or bone. This imaging characteristic occurs because the solid component of the cyst is not as prominent compared to the fluid-filled component, leading to the appearance that only a small part of the lesion (the "tip") is visible, while a larger, more complex structure is hidden beneath the surface. This detail is a key factor in differentiating dermoid cysts from other types of ovarian masses during imaging evaluations. Understanding this sign is crucial for radiologists and clinicians as it aids in the diagnosis and management of ovarian lesions, indicating a need for further evaluation or surgical intervention if necessary.