Professional and Linguistic Assessments Board (PLAB) Practice Exam

What condition does a whirlpool sign on ultrasound typically indicate?

1. Ovarian cyst

2. Uterine fibroids

3. Torsion

4. Ectopic pregnancy

The correct answer is: Torsion

The whirlpool sign on ultrasound is indicative of torsion, particularly in the context of the ovaries. This sign is characterized by the appearance of twisted vessels surrounding an enlarged, edematous ovarian mass. When an ovary undergoes torsion, the blood supply is compromised, leading to swelling and changes in the structure around the torsed ovary. The "whirlpool" effect visually represents the twisted vascular supply and is a critical finding that can help differentiate torsion from other potential gynecological conditions. In contrast, conditions such as ovarian cysts, uterine fibroids, and ectopic pregnancies do not typically present with the whirlpool sign. An ovarian cyst may show a simple fluid-filled appearance without the complex vascular involvement seen in torsion. Uterine fibroids, which are usually associated with a more homogeneous mass and potential effects on surrounding structures, do not create the same twisted vascular pattern. Ectopic pregnancy may show other signs, like an adnexal mass or free fluid, but it does not exhibit the whirlpool sign associated with torsion of the adnexa. Thus, the whirlpool sign is specifically linked with the acute process of torsion, making it a critical aspect in the diagnosis of this surgical emergency.