What is necessary for the diagnosis of chronic endometritis?

The presence of plasma cells in the endometrium is a key criterion for the diagnosis of chronic endometritis. Chronic endometritis is characterized by persistent inflammation of the endometrial lining, often associated with infection or retained products of conception. Plasma cells are indicative of chronic inflammation, as they are differentiated B lymphocytes that produce antibodies. Their presence suggests an ongoing immune response, which is typical in chronic endometritis.

In this context, other factors such as endometrial hyperplasia, thickened endometrial lining, and the absence of decidual cells may not be specific indicators of chronic endometritis. Endometrial hyperplasia can occur due to various other causes, thickening may be a nonspecific finding, and the presence or absence of decidual cells can complicate the diagnosis in different phases of the menstrual cycle or pregnancy. Thus, the identification of plasma cells remains the most definitive histological feature for diagnosing chronic endometritis.