Sometimes thick, sometimes thin, the "face-changing game" of the endometrium, how much do you know?

Author: Chen Yongning, attending physician of the First Affiliated Hospital of Jinan University

Reviewer: Gong Shipeng, Chief Physician, Nanfang Hospital, Southern Medical University

Endometrial thickening is a common problem for women during physical examinations and gynecological consultations. Some people are extremely worried and lose their appetite, while others don't care. When doctors recommend curettage or hysteroscopy, many women feel entangled, afraid, and at a loss. Today, we will talk to you about this problem from multiple aspects.

1. What is the endometrium?

The endometrium is the soil for the growth and development of the fetus, and its thickness and shape will change with the fluctuation of ovarian hormone levels. So, what is the normal endometrial thickness at different stages?

(1) Menstrual period (5th to 7th day of menstrual cycle): 4 to 6 mm;

(2) Proliferative phase (day 7 to 14 of the menstrual cycle): 5 to 10 mm;

(3) Secretory phase (days 15 to 28 of the menstrual cycle): 10 to 15 mm;

(4) Menopause: <4-5mm.

Usually, we will choose to do B-ultrasound just after the menstruation to determine whether the endometrium is thickened. At this time, the endometrium is the thinnest. If the thickness is >4-6mm, it is considered to be endometrial thickening. If you choose to do B-ultrasound in the middle and late stages of menstruation, the thickness is >15mm at this time, it is considered to be endometrial thickening. For postmenopausal women, if the endometrial thickness is ≥4-5mm, it is considered to be endometrial thickening. The evaluation and treatment of endometrial thickness requires comprehensive consideration of multiple factors and needs to be performed under the guidance of a professional doctor.

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2. What are the causes of endometrial thickening?

1. Pregnancy: After the fertilized egg implants, the endometrium will further proliferate and increase in thickness. In addition to normal early pregnancy, ectopic pregnancy and biochemical pregnancy may also be accompanied by endometrial thickening.

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2. Endocrine related: There are two types of endometrial thickening: physiological endometrial thickening during childbearing age and endometrial thickening caused by endocrine disorders during menopause. The first type is most common in the middle and late stages of menstruation, when ultrasound may reveal an endometrial thickness of >15mm. It cannot be blindly concluded that there is a problem, because individual differences are large, and this is likely to be a normal change; the second type occurs during menopause, when ovarian function declines, leading to anovulation, and the endometrium continues to be stimulated by a single estrogen, but lacks the antagonistic effect of progesterone, making it easy for the endometrium to thicken.

3. Benign endometrial lesions:

(1) Endometrial polyps: caused by excessive growth of the local endometrium of the uterus, which can be single or multiple.

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(2) Submucosal uterine fibroids: Uterine fibroids are common benign tumors in women. Submucosal fibroids refer to fibroids that grow in the uterine cavity or most of them protrude into the uterine cavity.

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4. Endometrial hyperplasia: refers to the irregular proliferation of endometrial glands, which is divided into two categories: endometrial hyperplasia without atypia and endometrial atypical hyperplasia. The former also includes simple endometrial hyperplasia, complex endometrial hyperplasia and excessive endometrial hyperplasia, and the risk of progression to endometrial cancer is about 5%. The risk of the latter progression to endometrial cancer is as high as about 28%.

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5. Endometrial malignant lesions: Endometrial cancer is relatively common and easy to detect in the early stages. In contrast, uterine sarcoma and carcinosarcoma are relatively rare, and most cases are diagnosed after uterine fibroid surgery.

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3. What are the symptoms of endometrial thickening?

Endometrial thickening may be asymptomatic, or may present with irregular menstruation (long cycles, long menstrual periods, heavy menstrual flow, non-menstrual bleeding, postmenopausal vaginal bleeding, etc.), abnormal vaginal discharge (bloody or serous, with a purulent odor when combined with infection), and lower abdominal pain, etc. However, these symptoms are not specific, so the condition cannot be judged based on symptoms alone.

4. What should be done further if endometrial thickening is confirmed?

1. Urine test: You can use a pregnancy test stick at home or go to the hospital for a urine pregnancy test to rule out pregnancy.

2. Blood test: The possibility of pregnancy is ruled out by testing the beta subunit of human chorionic gonadotropin (β-HCG) and at the same time, six sex hormones and anti-Mullerian hormone are tested to assess whether ovarian function is declining or there is abnormal secretion. In addition, testing tumor markers carbohydrate antigen 125 (CA125) and human epididymis protein 4 (HE4) can help diagnose whether there is a malignant lesion.

3. Gynecological B-ultrasound examination: measure the thickness of the endometrium and evaluate whether the endometrium has uneven echo, local protrusions, abnormal blood flow signals, etc.

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4. Curettage: For patients with prolonged bleeding, heavy bleeding, or risk of endometrial malignancy, curettage can not only effectively stop bleeding, but also clarify the cause of endometrial thickening. However, since curettage is a blind operation that relies on the doctor's feel, it may miss early endometrial cancer lesions.

5. Hysteroscopy: Use the slender front end of the scope to enter the uterine cavity and magnify the observed area, which can more intuitively and accurately observe the morphology, range and nature of the lesions in the uterine cavity. However, when the bleeding time is long and the amount of bleeding is large, the field of vision may be limited. It is usually performed within 3 to 7 days after the menstruation is over, when there is no bleeding or a small amount of bleeding. Hysteroscopy can be combined with curettage to more accurately determine the cause of endometrial thickening and avoid the subjectivity of simple curettage.

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5. What factors should be considered when treating endometrial thickening?

1. Age: Most young people consider excluding the possibility of pregnancy. If they are not pregnant, it is likely to be physiological thickening. It is recommended to recheck the B-ultrasound after the next menstrual period. For menopausal patients or those with symptoms of "second youth" after menopause, curettage and hysteroscopy should be considered to exclude the possibility of malignant transformation.

2. Check the bleeding time and amount: Patients with long bleeding time and heavy bleeding amount should first rule out pregnancy. If not pregnant, curettage should be performed actively to stop bleeding, and tissue should be taken for pathological examination to clarify the nature of the lesion (further hysteroscopy can be considered when bleeding stops).

3. Check whether there are high-risk factors for malignant transformation: obesity, hypertension, diabetes, infertility, polycystic ovary syndrome, etc. (manifested as anovulation or infrequent ovulation), long-term endocrine drug maintenance treatment for breast cancer, late menopause (>55 years old), postmenopausal disease, family history of endometrial cancer, ovarian cancer, colorectal cancer, breast cancer, etc., and patients who take health care products for a long time are prone to endometrial malignancy and need to take more active treatment measures.

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VI. Conclusion

There are many reasons for endometrial thickening, and the severity of the lesions varies. We should pay enough attention to it, but there is no need to panic. Most problems can be solved by adjusting lifestyle and drug treatment, but some patients still need long-term management to prevent recurrence or progression to cancer. For endometrial malignancy, surgery, radiotherapy and chemotherapy are required. Developing a good lifestyle and habits, regular physical examinations, and long-term disease management according to doctor's advice are of great significance for preventing the occurrence of endometrial lesions, early detection and treatment.