What is the Origin of Endometrial Lesions?

The term combines "endometrial," referring to the uterine lining, and "lesions," derived from the Latin laesio, which in a medical context denotes a localized region of tissue that has suffered damage or abnormal change. The clinical understanding of their hormonal etiology traces back to early observations linking estrogen replacement therapy without a counteracting progestogen to an increased incidence of endometrial proliferation. This historical link led directly to the established clinical practice of using progestogens to provide essential protection for the endometrium.

What is the Mechanism of Endometrial Lesions?

The primary mechanism driving the formation of many endometrial lesions involves the unopposed action of estrogen, which powerfully stimulates the proliferation of endometrial glandular and stromal cells by binding to intracellular estrogen receptors. When progesterone is absent or insufficient to oppose this action, the proliferative drive continues unchecked, leading to architectural disorganization and, eventually, genetic instability within the cells. This sustained, unbalanced hormonal signaling pathway drives the pathological progression from normal proliferative endometrium to hyperplasia and, in some cases, to malignant transformation.

Endometrial Lesions

Meaning

Endometrial lesions are abnormal growths or areas of tissue change that develop within the endometrium, which is the hormonally sensitive inner lining of the uterus. These structural deviations can span a wide clinical spectrum, ranging in severity from benign conditions, such as endometrial polyps or simple hyperplasia, to pre-malignant or frankly malignant endometrial carcinoma. The development of these lesions is often intrinsically linked to prolonged or unopposed exposure to estrogen, clearly highlighting the critical role of hormonal balance in maintaining uterine health and integrity. Accurate histological classification is essential for determining the appropriate clinical management and prognosis.