The fallopian tubes measure between 7 and 14 cm in length. They are composed of three layers: mucous, muscular and serous layer. The mucosal layer is located directly under the muscular layer that is formed by bundles of smooth muscle fibers with a circular arrangement in its interior and longitudinal fibers in the exterior.
The proximal tubal opening is called ostium tubaricum and plays an important role in the prevention of retrograde menstruation, in the transport of spermatozoa and in the transport of the embryo to the uterine cavity.
Polyps at the level of the tubal ostium present as small, well-defined lesions. According to Reasbeck, benign polypoid lesions in the intramural tubal portion are found in up to 10% of hysterosalpingograms performed on infertile patients. Many of these polypoid lesions are visible through hysteroscopy if the hysteroscope is placed close enough to the ostium. Interestingly, in a series of 52 polyps of this location resected by Gordts, all of them were made of endometrial tissue, despite the tubal location. Rarely they produce total obstruction of the lumen, and although the role they play in infertile patients is unclear, more and more authors believe that there is a clear relationship between tubal polyps and infertility.