title: Endometrial Synovial-like Metaplasia Associated With Levonorgestrel-releasing Intrauterine System.
abstract: The levonorgestrel-releasing intrauterine system (L-IUS) is widely used in contraception and in the treatment of menorrhagia, dysmenorrhea, adenomyosis, and endometriosis. L-IUS is also increasingly considered in the management of endometrial neoplasia and its precursors. Histologic changes in the endometrium can be due to the effects of high-dose progestogen or may be caused by the local irritant or mechanical effects of an intrauterine foreign body. In the present study, we describe a novel endometrial alteration associated with L-IUS that most closely resembles synovial metaplasia reported at other extra-articular anatomic sites. Eleven cases were identified with a mean age of 49.6 yr. In most patients L-IUS was used for management of menorrhagia or endometrial hyperplasia. Endometrial synovial-like metaplasia was always a focal finding and was associated with areas of surface epithelial erosion. The synovial-like cells showed a distinctive palisaded arrangement with orientation perpendicular to the endometrial surface. Multinucleate cells were present in 2 cases, but granulomas were not identified. The synovial-like cells were vimentin immunoreactive and a variable proportion of cells expressed CD68. Only focal CD10 staining was seen and there was no expression of estrogen receptor, progesterone receptor, or cytokeratin. In summary, L-IUS may be associated with a distinctive synovial-like metaplastic alteration which most likely represents a stromal reaction to an intrauterine foreign body following endometrial surface erosion. The synovial-like cells appear to comprise histiocytes and modified fibroblasts or stromal cells similar to this process in other sites.
authors.affiliation: Department of Histopathology (C.J.R.S.), King Edward Memorial Hospital, Subiaco School for Women's and Infants' Health (C.J.R.S.), University of Western Australia Hollywood Hospital (R.L.), Nedlands, Perth, WA, Australia.
authors.forename: Colin J R
authors.initials: CJ
authors.lastname: Stewart
authors.forename: Robyn
authors.initials: R
authors.lastname: Leake
mesh_terms: D000328:Adult; D015415:Biomarkers / Q000032:analysis; D003271:Contraceptive Agents, Female / Q000009:adverse effects*; D004714:Endometrial Hyperplasia / Q000188:drug therapy; D004717:Endometrium / Q000473:pathology*; D005260:Female; D005549:Foreign-Body Reaction / Q000209:etiology / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D007436:Intrauterine Devices, Medicated / Q000009:adverse effects*; D007889:Leiomyoma / Q000188:drug therapy; D016912:Levonorgestrel / Q000009:adverse effects*; D008595:Menorrhagia / Q000188:drug therapy; D008679:Metaplasia / Q000209:etiology* / Q000473:pathology; D008875:Middle Aged; D013583:Synovial Membrane / Q000473:pathology*
chemical_list: D015415:Biomarkers; D003271:Contraceptive Agents, Female; D016912:Levonorgestrel