BACKGROUND: The intrauterine device (IUD) is a commonly used contraceptive method in emerging countries, such as Mexico and several Latin American nations. IUD insertion is a well-described and relatively simple procedure; however, one of its rare complications is migration to nearby extrauterine structures.

CASE REPORT: The patient was a 37-year-old woman with a history of cesarean delivery 5 years earlier. After an abortion managed by instrumental uterine curettage in 2024, a copper intrauterine device (IUD) was placed, with no immediate complications. However, 1 month later, she experienced intermittent mild cramping in the lower abdomen, which intensified 1 year later (2025) and for which she sought medical evaluation. The initial examination included a pelvic ultrasound, which revealed the absence of the IUD within the uterine cavity. After a hysteroscopy and computed tomography (CT), the gynecology and obstetrics department performed an exploratory laparotomy. The transoperative findings were as follows: right iliac fossa with displaced IUD, whose arms were located in the right fimbria, while the body of the device was apparently visible within the appendicular lumen. The cecal appendix showed no macroscopic evidence of pathology. The patient’s progress was satisfactory, with no immediate or delayed complications.

CONCLUSIONS: This case is the first record in the medical and scientific literature in which the IUD was found intraluminally in the appendix, without macroscopic or clinical data of acute appendicitis. This case also highlights the need for early diagnosis and timely treatment of seemingly rare conditions, to reduce complications arising from procedures considered routine, such as IUD insertion.

Keywords: Appendix, Intrauterine Device Migration, Intrauterine Devices, Copper