endometrial

The endometrium is the mucous membrane lining the interior of the uterus. The term endometrial refers to anything related to this lining. It consists of glandular epithelium and stroma, with blood vessels and immune cells, and it undergoes cyclical remodeling during reproductive years.

During the menstrual cycle, estrogen stimulates proliferation of the endometrium (proliferative phase), followed by progesterone-induced secretory transformation after ovulation (secretory phase). If fertilization does not occur, withdrawal of progesterone triggers shedding of the functional layer (menstruation).

The functional layer is the inner portion that changes with the cycle; the basalis remains. Endometrial thickness is assessed by ultrasound and varies with age and cycle phase; abnormal thickening can indicate pathology.

Endometrial hyperplasia refers to thickening that may be due to excess estrogen and can progress to cancer if atypia is present. Endometrial cancer, often adenocarcinoma, is a common gynecologic cancer in developed countries. Endometrial tissue outside the uterus characterizes endometriosis, a condition causing pelvic pain and infertility.

Diagnosis and management: Abnormal uterine bleeding is evaluated with medical history, imaging, and sometimes endometrial sampling via biopsy or dilation and curettage. Treatments depend on the diagnosis: hormonal therapies (progestins, levonorgestrel-releasing IUD) to regulate cycles or treat hyperplasia; surgery (hysterectomy) for cancer or severe disease; management of endometriosis may include hormones, pain control, and sometimes surgery.