Morphological alterations in endometrium after use of levonorgestrel-releasing intrauterine system: a case report

Case Report: A 44-year-old patient attended the gynecology service for routine consultation. The patient reported implantation of a levonorgestrel-releasing intrauterine system (LNG-IUS), five years ago. No macroscopic changes were seen in the uterus or in the endometrium cavity during the procedure, but an endometrial biopsy was performed. Histopathological analysis revealed an endometrium with an expanded stroma by pseudo-decidualization and mucoid (mucinous) alterations, forming small puddles of mucin, also presenting with polypoid indentations, ectatic vessels, lymphoid cell foci, including plasma cells and deposits of calcium salts. Conclusion: As the use of this type of contraceptive method becomes more usual, knowledge of LNG-IUS-induced changes becomes increasingly relevant for the assessment of its long-term efficacy and safety.