Causes of Endrometriosis
There are many theories as to what causes endometriosis. Unfortunately none of these theories have been extensively proven. The most popular theory of retrograde menstruation propogated by Sampson is still being touted as the most likely cause of endometriosis till today, even though there is large evidence to the contrary. Unfortunately medical syllabi do not undergo timely upgrades unlike our smartphones.
Sampson’s theory of retrograde menstruation states that During menstruation, pieces of endometrium arrive in the abdominal cavity through the Fallopian tubes, adhere to the peritoneal lining and develop into endometriotic lesions.
For over 8 decades now people have wrongly believed that endometriosis consists of the endometrial lining of the uterus. It has low and varying levels of hormone receptors compared to native endometrial tissue and behaves differently than native endometrium.
Metaplasia means to change from one normal type of tissue to another normal type of tissue. It has been proposed by some that endometrial tissue has the ability in some cases to replace other types of tissues outside the uterus.
Some researchers believe this happens in the embryo, when the uterus is first forming. Others believe that some adult cells retain the ability they had in the embryonic stage to transform into reproductive tissue.
The most plausible theory with what knowledge we have today is Mülleriosis, the current best-fit model of the origin of endometriosis, refers to a developmental defect in the differentiation or migration of any cellular component of the müllerian duct system during embryonic development.