Causes of uneven uterine echo

When women go to the hospital to check their uterus, they need to do many tests. During the examination, some people will find that the echo of the uterus is uneven. Under normal circumstances, the echo of a healthy uterus should be uniform. If it is uneven, it is very likely that there is a problem in the uterus. You should consult a doctor in time and get treatment as soon as possible. Let’s take a look at the reasons why the uterine echo is uneven.

1. Cyclic changes of the endometrium

Before explaining the reasons for endometrial thickening and uneven echo, we must first understand the cyclical changes of the endometrium. Because the thickness of the endometrium is closely related to the cyclical changes of the endometrium.

The endometrium is divided into the basal layer and the functional layer. The functional layer of the endometrium is regulated by changes in ovarian hormones and has periodic changes in proliferation, secretion, and shedding, while the basal layer of the endometrium can regenerate after menstruation and repair endometrial wounds. According to the changes in the endometrial tissue, the menstrual cycle is generally divided into three phases: proliferative phase, secretory phase, and menstrual phase.

1. Menstrual period: During this stage, the endometrium is thinner, with a thickness of about 3 to 6 mm. It has uneven echoes at first, and becomes uniform and equal echoes after the menstruation is basically over. The layered structure of the endometrium is unclear, and the uterine cavity line between the two layers of endometrium is clear.

2. Proliferative stage: In this stage, the endometrial glands proliferate, the endometrial functional layer appears low echo, the basal layer appears high echo, and the high echo of the uterine cavity line forms a "three-line sign". This stage is divided into early (A) and middle and late stages (B). During this stage, the endometrium gradually thickens and reaches a thickness of about 10 mm.

3. Secretory phase: During this stage, the endometrium undergoes a secretory reaction, and the thickness of the endometrium increases slightly. The basal layer of the endometrium gradually changes to an endometrial layer with a slightly stronger echo than the myometrium (Figure C above). The thickness of the endometrium during the secretory phase can reach 10 to 13 mm, and the entire layer of the endometrium becomes a relatively homogeneous high echo.

2. Causes of endometrial thickening and uneven echo

B-ultrasound examination found that the endometrium was thickened and the echo was uneven. There are several reasons for this:

1. Endometritis

Ultrasound reveals that endometrial thickening and uneven echoes are mostly caused by endometritis. The main clinical manifestations of endometritis are lower abdominal distension, lumbosacral pain, increased or bloody leucorrhea, increased menstrual flow, and dysmenorrhea.

2. Endometrial hyperplasia

It is an abnormal proliferation of endometrial glands and stroma. It is a benign lesion. The endometrial thickening can reach 3 to 25 mm. It is more common in puberty and menopause, including simple hyperplasia, cystic hyperplasia, adenomatous hyperplasia, and atypical hyperplasia. Common symptoms include irregular uterine bleeding, menstrual cycle disorders, heavy menstrual flow, shortened or significantly prolonged menstruation. B-ultrasound shows uniform thickening and symmetry of the endometrium, with the uterine cavity line centered. In atypical hyperplasia, the endometrial echo is uneven, with alternating plaques and low echoes.

3. Endometrial polyps

Endometrial polyp is a pedunculated tumor-like lesion formed by localized proliferation and protrusion of endometrial glands and fibrous stroma, but it is not a true tumor. It is more common in women aged 40 to 50. Its main clinical manifestations are increased menstrual flow, prolonged menstrual period, increased leucorrhea, postmenopausal uterine bleeding, etc. It may also have no obvious symptoms and be discovered during physical examination. When single, B-ultrasound shows an inhomogeneous low-echo or high-echo mass in the uterine cavity, which is clearly demarcated from the normal endometrium. When there are multiple polyps, the intima is thickened and has uneven echoes. Irregular clusters of high-echo spots are seen in the intima, and the boundary between the intima and the normal intima is unclear.

4. Endometrial cancer

It is a group of epithelial malignant tumors that occur in the endometrium. It is one of the three most common malignant tumors in women. 80% of them occur in postmenopausal women, with endometrial adenocarcinoma being the most common. The peak age is 50 to 60 years old, most of whom are postmenopausal. There may be no symptoms in the early stage, and the main manifestations are irregular uterine bleeding, postmenopausal uterine bleeding, and increased leucorrhea. In the late stage, it may manifest as lower abdominal pain and systemic symptoms. B-ultrasound shows uneven echoes in the uterine cavity, thickened endometrium with uneven echoes, and when the tumor invades the myometrium, the uterus becomes enlarged and deformed, with unclear contours.