Morphologic Changes in the Endometrium Associated With the Use of the Mirena Coil: A Retrospective Study of 106 Cases

Abstract

This study outlines the histologic changes seen in 106 endometrial specimens after use of the Mirena coil (levonorgestrel) and compares these changes with previous studies. The variables assessed include nature of the endometrial glands, metaplastic glandular changes, nuclear atypia, hobnail change, and endometrial hyperplasia. Stromal changes include pseudodecidualization, mucinous change, ulceration, and infiltration by granulocytes, neutrophils, and plasma cells, and stromal hyaline nodules, a feature not described previously. Additional changes include superficial micropapillary change, infarcted decidua, dystrophic calcification, hemosiderophages, polypoid indentations, cervical microglandular hyperplasia and endocervical pseudodecidualization. These variables are compared with a similar previous study. Significant differences in the incidence of glandular metaplasia, dystrophic calcification, plasma cell infiltrates, hemosiderophages, and presence of nuclear atypia are noted. With increased use of the Mirena coil, histopathologists need to be aware of the characteristic and constant endometrial changes due to progestogenic and mechanical effects, despite a wide variation in the duration of usage.

Recent Developments in Surgical Pathology of the Uterine Corpus

“…Histologic findings described in leiomyomas associated with progestin therapy include increased mitotic activity, stellate hemorrhage (apoplectic change), and ''red degeneration.'' 69,70 Additional common findings described by Boyd and McCluggage 71 are early infarct-type necrosis, often multifocal without a reparative rim of granulation tissue (which could be mistaken for coagulative tumor cell necrosis), mitotic count of up to 10 mitoses/10 HPFs, and focal myxoid change. The most characteristic progestin-associated change is the appearance of myocytes with pyknotic nuclei and abundant deeply eosinophilic cytoplasm adjacent to the necrotic areas.…”

Endometrial metaplasias and reactive changes: a spectrum of altered differentiation

“…EMCs and hyperplasia are not mutually exclusive lesions and they often coexist and overlap, since both are related to unopposed oestrogen stimuli 9. Furthermore, EMCs have also been described in endometria of patients with progesterone-coated intrauterine devices,10 and even associated with the new selective progesterone-receptor modulators 11. As a rule, EMCs are frequently seen in endometrial polyps, endometriosis12 13 and in the benign epithelial component of some tumours such as adenosarcomas 14.…”

Levonorgestrel-releasing intrauterine system (LNG-IUS) as an effective treatment option for endometrial hyperplasia: a 15-year follow-up study

“…Successful treatment was defined as histologic regression (glandular atrophy and stroma decidualization) during intrauterine hormonal delivery or at the time of LNG-IUS removal (4)(5)(6)(7)(8)(10)(11)(12)(13). However, even if these hormonal effects have been termed ''regression,'' they do not represent a defined histologic entity except in the context of follow-up of endometrial hyperplasia, and their stable conversion into atrophy or functional endometrium after the end of treatment remains a critical issue to be fully investigated.…”