Histologisch nachweisbare mikroskopische Endometrioseläsionen

Introduction: Occult microscopically endometriosis was firstly described by Murphy et al (1986). Since than no conclusion about the clinical significance of it was found. Firstly, occult microscopically endometriosis could be a physiological phenomenon, which occurs in women with and without endometriosis. Secondly, it could also be an early stage of real endometriotic lesions and would thus perhaps support Sampsons theory about retrograde menstruation. To find out more about the clinical significance of occult microscopically endometriosis, macroscopically normal tissue from the paracolic gutters from women with and without endometriosis was examined and compared to each other. Methods: For this study, tissues from the left and/or right paracolic gutter from 64 women with and 22 women without endometriosis had been surgically removed. Afterwards the tissues had been fixed and embedded in paraffin and finally immunohistochemically stained with antibodies of an estrogen receptor alpha, a progesterone receptor, cytokeratin, cluster of differentiation 10 and anti smooth muscle actin. Results: Occult microscopically endometriotic lesions were found in five of the 86 patients (5,81%). One of these lesions was found in a woman without endometriosis which is 4,5% of the control group. The other four lesions were found in women with endometriosis which is 6,3% of the cohort. Four of the lesions were located in the right paracolic gutter. The progesterone receptor did the strongest antibody binding of the glandular and stromal cells whereas there were only a few cells that had shown an antibody binding with the estrogen receptor alpha. Besides this, there were also immune cells found in in the tissue of 12 women with endometriosis (18,8% of this cohort) but in none of the control group. These findings did not correlate with the occult microscopically endometriotic lesions. Conclusion: As there was no significant difference in the frequency of occurrence of occult microscopically endometriosis in women with and without endometriosis, it could be a physiological progress, in which endometrial cells settle in the peritoneal cavity and later get remoted by the endogenous immune system. The distribution of the hormonal receptors would support this statement. Furthermore, the distribution of the occult microscopically endometriotic lesions suggests that the peritoneal fluid affects the settlement of these lesions, as four of them were found in the right paracolic gutter.Regarding the inflammatory cells in the peritoneal tissue of women with endometriosis, the question arises whether these are the reason for or an effect of the disease.