Oorzaken van endometriose
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Sampson described Cystic ovarian endometriosis in 1921.
Because of endometriosis in women without a uterus the metaplasia theory was proposed.
Only ofter 1975 we realised that typical lesions were so frequent.
In 1986 Janssens described the non-pigmented subtle endometriosis
The history of deep endometriosis starts with the paper of Cornillie and Koninckx in 1989
The Implantation - the metaplasia theory
In 1921 Sampson proposed that menstrual cells that arrive in the peritoneal cavity by retrograde menstruation can implant and can develop further to endometriotic lesions. This theory is attractive since it has been proven that retrograde mentration occurs in most women, that this fluid contains viable cells and that these cells can inplant.Key in this theory is that endometriosis are ‘normal cells in an abnormal environment’ ie the peritoneal cavity.
This theory fails to explain why progression occurs in some women only, why endometriosis is heriditary etc.
This theory is based upon the fact that mesothelial cells in the peritoneum can be transformed by menstrual blood into endometrial cells.
Progression and further development is identical to the implantation theory.
Key in this theory is that implantation/metaplasia is the most important event whereas progression will occur for unknown reasons
The endometriotic disease theory
The EDT (Koninckx P.R., Kennedy S., Barlow D., Gyn Obstet Invest 1999,47,1-10) accepts that implantation/metaplasia occurs, but considers this a normal physiologic condition occurring in all women inermittently. Therefore the early ‘subtle’ lesions are considered not important which is consitent with the clinical observation that they do not cause pain or infertility. When one of these cells is transformed, progression starts into typical, cystic or deep lesions. Endometriosis this becomes a benign tumour, ie a non-malignant abnormal cell.
The main advantage of the EDT is that it easily explains why progression occurs, why very severe lesions can be found in very young women, why the disease is heriditary, why deep and cystic endometiosis are clonal in origin, why after complete excision recurrence is rare (if not absent), why dioxin and irradiation can stimulate the development. As any benign tumour surgical excision is the preferred treatment.
Haematogenic and lymfogenic spread
Haematogenic spread explains the occurrence of endometriosis in the lungs and on the pleura.
In deep endometriosis endometrial cells are found in 50% of women in the lymph nodes. The significance of this is unclear.