title: Nodular smooth muscle metaplasia in multiple peritoneal endometriosis.
abstract: We report here an unusual presentation of peritoneal endometriosis with smooth muscle metaplasia as multiple protruding masses on the lateral pelvic wall. Smooth muscle metaplasia is a common finding in rectovaginal endometriosis, whereas in peritoneal endometriosis, smooth muscle metaplasia is uncommon and its nodular presentation on the pelvic wall is even rarer. To the best of our knowledge, this is the first case of nodular smooth muscle metaplasia occurring in peritoneal endometriosis. As observed in this case, when performing laparoscopic surgery in order to excise malignant tumors of intra-abdominal or pelvic organs, it can be difficult for surgeons to distinguish the metastatic tumors from benign nodular pelvic wall lesions, including endometriosis, based on the gross findings only. Therefore, an intraoperative frozen section biopsy of the pelvic wall nodules should be performed to evaluate the peritoneal involvement by malignant tumors. Moreover, this report implies that peritoneal endometriosis, as well as rectovaginal endometriosis, can clinically present as nodular lesions if obvious smooth muscle metaplasia is present. The pathological investigation of smooth muscle cells in peritoneal lesions can contribute not only to the precise diagnosis but also to the structure and function of smooth muscle cells and related cells involved in the histogenesis of peritoneal endometriosis.
authors.affiliation: Department of Pathology, Severance Hospital, Yonsei University College of Medicine Seoul, Republic of Korea.
authors.forename: Hyun-Soo
authors.initials: HS
authors.lastname: Kim
authors.affiliation: Department of Gynecology and Obstetrics, Pusan National University Yangsan Hospital, Pusan National University School of Medicine Yangsan, Republic of Korea.
authors.forename: Gun
authors.initials: G
authors.lastname: Yoon
authors.affiliation: Department of Pathology and Translational Genomics, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul, Republic of Korea.
authors.forename: Sang Yun
authors.initials: SY
authors.lastname: Ha
authors.affiliation: Department of Pathology and Translational Genomics, Samsung Medical Center, Sungkyunkwan University School of Medicine Seoul, Republic of Korea.
authors.forename: Sang Yong
authors.initials: SY
authors.lastname: Song
mesh_terms: D015415:Biomarkers / Q000032:analysis; D001706:Biopsy; D004715:Endometriosis / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D005260:Female; D005629:Frozen Sections; D006801:Humans; D006965:Hyperplasia; D007150:Immunohistochemistry; D010535:Laparoscopy; D008875:Middle Aged; D009130:Muscle, Smooth / Q000737:chemistry / Q000473:pathology* / Q000601:surgery; D010532:Peritoneal Diseases / Q000378:metabolism / Q000473:pathology* / Q000601:surgery
chemical_list: D015415:Biomarkers
keywords: Endometriosis; metaplasia; pelvic wall; peritoneum; smooth muscle cells