Pathogenesis of peritoneal endometriosis

The transplantation theory, proposed by Sampson in 1927, involves the dissemination of viable epithelial and stromal endometrial cells via the fallopian tubes into the abdominal cavity and the implantation of these cells into the peritoneum, leading eventually to endometriotic lesions.1According to this theory, retrograde menstruation, peritoneal adhesion of shed endometrial tissue, and cells outgrowth are the three essential steps resulting in endometriosis.