[Endometritis : Rare disease with clinical importance?]

Endometritis is nowadays rare in developed countries and typically shows a subclinical or mild course; therefore, there are probably more cases of endometritis than diagnosed but they lack clinical relevance. In the fertile period of life it can be the reason for vaginal bleeding and infertility. The most common causes for non-specific endometritis are residual placental tissue after abortion or childbirth, intrauterine interventions, lesions within the uterine cavity, such as endometrial polyps, endometrial hyperplasia and neoplasms, intrauterine devices (IUD) and cervical stenosis. The histological detection of plasma cells in the endometrial stroma is required for the diagnosis of chronic endometritis. These can be detected immunohistochemically using anti-CD138 antibodies, which should be carried out particularly in cases of infertility with only slight inflammatory symptoms and few plasma cells. The use of an IUD containing progestin is frequently associated with an asymptomatic lymphoplasmacytic infiltration. After curettage or endometrial biopsy, an eosinophilic xanthogranulomatous or granulomatous endometritis and also a foreign body granuloma reaction can occur. Specific forms of endometritis, such as caused by tuberculosis, sarcoidosis, mycoplasma and herpes are very rare. Cytomegalovirus endometritis is associated with immunosuppression. Endometritis caused by infections with Chlamydia trachomatis is characterized by an extensive lymphoplasmacytic infiltration. The differential diagnoses of chronic endometritis include the very rare malignant lymphoma, which is usually characterized by a relatively monotonous cell infiltration.