What is endometrial hyperplasia?

Endometrial hyperplasia | Cleveland Clinic

Endometrial hyperplasia is a condition in which the endometrium (the lining of the uterus) becomes abnormally thick. Although endometrial hyperplasia is not cancer, it can lead to uterine cancer in some women.

Endometrial hyperplasia is usually caused by an excess of estrogen without progesterone (female hormones). The progesterone is not made and the lining of the uterus is not shed if ovulation does not occur. This means that the endometrium may continue to grow in response to the production of estrogen. The cells of the endometrium may abnormally crowd (hyperplasia), which may lead to the cancer of the uterus.

What is atypical endometrial hyperplasia?

Atypical endometrial hyperplasia is a premalignant condition of the endometrium. It occurs when there is an overgrowth of abnormal cells, or it may develop from endometrial hyperplasia. In some cases, polyps (tumors) in the uterus can lead to atypical endometrial hyperplasia.

Who is at risk for developing atypical endometrial hyperplasia?

Atypical endometrial hyperplasia usually develops in older women (after menopause). But it can develop in younger women if they do not ovulate or are obese.

What are the causes of atypical endometrial hyperplasia?

Atypical endometrial hyperplasia develops when there is no balance between the female hormones, estrogen and progesterone. This imbalance is called unopposed estrogen and it may be caused by a number of factors including:

  • Hormone changes during menopause (cessation of menstrual period)
  • Estrogen-hormone replacement therapy
  • Breast cancer treatment, using drugs such as tamoxifen (Nolvadex®, Tamofen®)

Normal Uterine Anatomy | Cleveland Clinic

What are the symptoms of atypical endometrial hyperplasia?

Abnormal vaginal bleeding is the most common symptom of atypical endometrial hyperplasia. Less common symptoms include abnormal vaginal discharges or an abnormal Pap test result.

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