Chronic endometritis

by Jason Wasserman MD PhD FRCPC
September 10, 2024

Chronic endometritis is a long-term or chronic inflammation of the endometrium, the inner lining of the uterus. Unlike acute inflammation, which happens suddenly and resolves quickly, chronic endometritis develops over an extended period and may cause persistent symptoms. This condition is often associated with an infection, although no clear infection is found in some cases. Chronic endometritis can affect a woman’s reproductive health and may contribute to issues such as infertility or recurrent miscarriage.

What are the symptoms of chronic endometritis?

The symptoms of chronic endometritis can vary, and some women may not have any noticeable symptoms. Common signs include:

• Abnormal uterine bleeding (heavy or irregular periods).
• Pelvic pain or discomfort.
• Unusual vaginal discharge.
• Pain during intercourse.
• Infertility or difficulty getting pregnant.
• Recurrent miscarriages.

If you experience these symptoms, it’s important to consult a doctor for further evaluation.

What causes chronic endometritis?

Chronic endometritis is often caused by a persistent infection in the uterus. Common infections that can lead to chronic endometritis include:

• Bacterial infections (such as those caused by Escherichia coli or Enterococcus species).
• Sexually transmitted infections (STIs) like chlamydia or gonorrhea.
• Tuberculosis (in rare cases).

Chronic endometritis can also occur after procedures like a dilation and curettage (D&C) or intrauterine device (IUD) placement. Sometimes, no clear cause is identified.

How is this diagnosis made?

Chronic endometritis is diagnosed through a combination of medical history, symptoms, and a biopsy of the endometrial tissue. A small sample of the endometrial lining is taken during a procedure called an endometrial biopsy and examined under a microscope by a pathologist. In some cases, cultures or other tests may be done to identify specific bacteria or infections causing the inflammation.

What are the microscopic features of chronic endometritis?

Under the microscope, chronic endometritis shows several characteristic features:

• Plasma cells in the endometrium: Plasma cells, a type of immune cell, are a key feature of chronic endometritis. Their presence in the endometrial tissue indicates long-term inflammation.
• Lymphocytes and other immune cells: Chronic endometritis often shows a mixture of other immune cells, including lymphocytes, which are also involved in the inflammatory response.
• Irregular gland structure: The endometrial glands may appear irregular or disorganized, reflecting the effects of chronic inflammation on the normal structure of the tissue.
• Fibrosis or scarring: In some cases, long-term inflammation can lead to fibrosis or thickening of the tissue due to scar formation.

These microscopic features help pathologists confirm the diagnosis of chronic endometritis and may guide further treatment to address the underlying cause.