Ultrasound manifestations of various types of uterine fibroids

Uterine fibroids are the most common benign tumors of the female genitalia. They are composed of smooth muscle and connective tissue and are common in women aged 30 to 50 years old. They are rare in women under 20 years old. According to the relationship between the fibroids and the uterine muscle wall, they can be divided into intramural fibroids, subserosal fibroids, and submucosal fibroids. The related B-ultrasound manifestations of various types of uterine fibroids are as follows:

1. Submucosal fibroids

Submucosal uterine fibroids generally grow into the cavity. When there is a single submucosal fibroid, the shape of the uterus can remain the same, but the volume increases. B-ultrasound can show that the echo of the endometrium changes from a straight line to an arc.

2. Intramural fibroids

Intramural fibroids often cause uneven enlargement and deformation of the uterus, localized bulges, and a smaller uterine cavity. Ultrasound can show abnormal uterine morphology, round or oval echoes of fibroids, and a "dark ring surrounding sign" on the surface, with the fibroids being equidistant from the inner and outer layers.

3. Subserosal fibroids

When a subserosal fibroid is seen, the mass is usually quite large. It is a substantial mass protruding inward from the uterus. It may have a wide or narrow base, or even be connected to the uterus with a pedicle. The shape is often irregular, with a clear boundary with the surrounding tissue. If the pedicle is not supplied with enough blood, the fibroid may become necrotic; if the pedicle is twisted and broken, the tumor will fall off to form a free fibroid. When the pedicle of the mass is thin or breaks off to form a parasitic uterine fibroid, it is difficult to distinguish it from an ovarian tumor by B-ultrasound.