Infiltrating endometriosis of the urinary tract: Mechanisms of growth and progression. Clinical, morphological, and immunohistochemical examinations

Objective: to reveal the clinical, morphological, and immunohistochemical features of infiltrating endometriosis of the urinary tract, as well as the role of cells with the signs of stemness in its pathogenesis. Subjects and methods. The investigation enrolled 62 patients who had been examined and treated at the V.I. Kulakov Research Center of Obstetrics, Gynecology, and Perinatology for infiltrating endometriosis involving the urinary tract in the period February 2010 to May 2015. The patients were divided into two groups. Group 1 consisted of patients with infiltrating endometriosis of the urinary tract who had sought medical advice for this disease for the first time. Group 2 included patients with infiltrating endometriosis of the urinary tract who had been previously treated for endometriosis. A control group (Group 3) was made up for immunohistochemical examination. Groups 1 and 2 patients underwent physical examination and all necessary clinical, laboratory, and instrumental studies (ultrasonography, magnetic resonance imaging, computed tomography, coloscopy, and cystoscopy) for specifying the diagnosis and preparing for surgical treatment. The latter was performed in 61 patients; 1 patient was discharged home prior to surgery due to family circumstances. The normal endometrium during the proliferative phase, which had been taken from 10 women (surrogate mothers), was examined in the control group (Group 3). Histological examination was performed in 61 patients. Immunohistochemical examination was done in 25 patients: 5 from Group 1, 10 from Group 2, and in 10 from the control group. Results. In recurrent endometriosis of the urinary tract, the intestine was more commonly involved in the endometrioid process. In Group 2, double endometrioid infiltrations of various intestinal portions were also encountered in the same patient. Morphological examination showed that the endometrioid foci possessed the properties of active foci. The recurrent foci more frequently displayed cystically transformed glands with polypoid proliferations of the epithelium and fibrosis of the adjacent tissues. Studying the results of immunohistochemical reactions discovered the specific features of the expression of epithelial and mesenchymal differentiation markers (CKWw, Cld3, and Vimentin), and those of stemness markers (PTEN, CD15, ALDH1, Musashi, and SOX2) in the endometrioid heterotopies and autologous endometrium. Conclusion. The endometrioid heterotopies differ from the autologous endometrium not only in their structure, but also in the degree of maturity of cells and their molecular arrangement according to Vimentin-у, Musashi, ALDH1, CD15, and SOX2. The endometrioid heterotopies have higher expression of the stemness markers, suggesting their relative immaturity, which manifests itself as higher active proliferation and infiltrative growth.

endometriosis of the urinary tract, immunohistochemical examination, expression of stemness markers in the endometrioid foci, epithelial-mesenchymal transformation