Histological findings in a falloposcopically retrieved isthmic plug causing reversible proximal tubal obstruction

We present the case of a 33-year-old woman with a 10 year history of infertility. Transvaginal falloposcopy revealed a proximal tubal occlusion (PTO) on the right due to a tissue plug. The plug was removed during dilatation of the tubal lumen. After the procedure patency for dye was restored. Histological and immunohistochemical findings--for the first time, to the best of our knowledge, performed in a falloposcopically retrieved plug--revealed the diagnosis of an inflammatory polyp arising from the tubal mucosa with focal calcifications. Local obstructive inflammatory residues of a previously treated tubal endometriosis, which was accompanied by features of salpingitis isthmica nodosa, are considered the most likely cause for this condition. Other possible aetiological factors responsible for PTO are discussed.