{"paper_id":"31c04982-ee4e-4bc7-9bf0-187bc9779e10","body_text":"A portion of the fimbriated end of the fallopian tube known as the fimbria ovarica extends along the lateral edge of the mesosalpinx to the ovary to which it is attached at its lateral pole. Seventy-four examples of fimbrial plicae that were attached to the ovary or broad ligament and lacked features of adhesions were studied. The fimbrio-ovarian attachments were characterized by one or more of the following: continuity between the tubal epithelium and either the ovarian surface epithelium, peritoneum, or both, in 51 cases; direct continuity of the ovarian stroma into the stroma of the fimbria ovarica in 42 cases; and direct insertion of plicae into the ovarian surface or ovarian stroma in 18 cases. In 21 cases, there was a direct attachment of plicae to the broad ligament close to the ovary. The mean size of the fimbria ovarica was 6.6 mm. The plicae were lined by normal tubal-type epithelium. The plical morphology was typically abnormal displaying one or more of the following features: short and blunted in 24 (32%), thickened in 18 (24%), elongated in 14 (19%), fusion in 13 (18%), edema in 13 (18%), and fibrosis in 11 (15%). Also noted were a mesothelial component in 69 cases (93%), the tubal-peritoneal junction in 53 cases (72%), transitional cell metaplasia/Walthard cell nests in 11 cases (15%), and foci resembling incipient fimbrial adenofibroma in 7 cases (9%). An understanding of the microanatomy and histology of the fimbria ovarica has important implications, particularly as: (a) portions may be left behind after prophylactic salpingectomy, providing a nidus for future development of high grade serous carcinoma (HGSC); (b) it constitutes an anatomic connection that may facilitate the spread of HGSC to the ovary, and (c) epithelial junctions are hotspots for carcinogenesis, and stem cells arising in such regions may be a source of HGSCs. In addition, understanding the fimbria ovarica has implications for the pathogenesis of ovarian surface epithelial inclusions, endosalpingiosis, and certain types of infertility. Its potential role as a site of origin of extrauterine HGSC, which typically arises in the fimbriae as serous tubal intraepithelial carcinoma, remains to be investigated.\nUncloaking the Fimbria Ovarica\nHistologic Recognition of an Elusive Anatomic Structure\nPlain Language SummaryThis study examined the fimbria ovarica, a part of the fallopian tube that connects to the ovary, in 74 cases. Researchers found various types of attachments and abnormal features in the fimbrial plicae, such as blunted, thickened, or elongated shapes. The study highlights the potential implications of the fimbria ovarica for the development and spread of high-grade serous carcinoma (HGSC), as portions may be left behind after prophylactic salpingectomy or facilitate cancer spread to the ovary. Understanding the fimbria ovarica is important for addressing risks related to HGSC, the pathogenesis of ovarian surface epithelial inclusions, endosalpingiosis, and certain types of infertility.\nText is machine generated and may contain inaccuracies. FAQ","source_license":"CC0","license_restricted":false}