Endometriosis of the round ligament: description of a clinical case and review of the literature.

We report a case of endometriosis of the round ligament in a 29-year-old woman, who complained of a lump with a diameter of about 2.5 cm in the right inguinal region, which increased in bulk and was accompanied by intense pain during the menstrual period. The clinical suspicion of inguinal endometriosis, supported by ultrasonography and Magnetic Resonance (MR), was confirmed by histological examination of the surgical specimen, which included the mass and the extraperitoneal segment of the round ligament. The authors conclude that the appearance of a lump in the inguinal region associated with subjective and objective changes of the lesion in relation to the menstrual cycle must raise the suspicion of endometriosis among the possible diagnoses.