title: A Case of Extragonadal Teratoma in the Pouch of Douglas and Literature Review.
abstract: Mature cystic teratoma is a germ cell tumor of the ovaries and is often observed in clinical practice. However, extragonadal teratomas are rare tumors and have been reported outside the ovaries, (e.g., in the greater omentum). The mechanism underlying the development of extragonadal teratomas remains unknown. We encountered a case of extragonadal teratoma in the pouch of Douglas that appeared to be a parasitic dermoid cyst. From our experience and the literature review, we discuss the potential mechanism leading to the development of extragonadal teratomas. A 41-year-old nonpregnant woman was referred to our department due to myoma and anemia. A 4-cm asymptomatic mass in the pouch of Douglas was observed, and the patient was diagnosed with ovarian mature cystic teratoma. She underwent laparoscopic surgery, and intraoperative findings revealed that the fallopian tube was injured and torn, and a residual small ovary was observed in the left side of the ovary. A tumor measuring approximately 4 cm observed in the pouch of Douglas was extracted without rupturing. The tumor was diagnosed as a parasitic dermoid cyst by macroscopic and histopathological findings. Auto-amputation could be the underlying mechanism that leads to an isolated parasitic dermoid cyst in the pouch of Douglas.
authors.affiliation: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Mamoru
authors.initials: M
authors.lastname: Kakuda
authors.affiliation: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan. Electronic address: zacky@gyne.med.osaka-u.ac.jp.
authors.forename: Shinya
authors.initials: S
authors.lastname: Matsuzaki
authors.affiliation: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Kobayashi
authors.affiliation: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Yoshino
authors.affiliation: Department of Pathology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Eiichi
authors.initials: E
authors.lastname: Morii
authors.affiliation: Department of Obstetrics and Gynecology, Osaka University Graduate School of Medicine, Osaka, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kimura
mesh_terms: D034861:Abdominal Wall / Q000473:pathology*; D000328:Adult; D003884:Dermoid Cyst / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D005260:Female; D006801:Humans; D010535:Laparoscopy / Q000379:methods*; D009373:Neoplasms, Germ Cell and Embryonal / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D009852:Omentum / Q000473:pathology*; D010051:Ovarian Neoplasms / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery; D035583:Rare Diseases; D013724:Teratoma / Q000175:diagnosis* / Q000473:pathology / Q000601:surgery
keywords: Auto-amputation; Douglas; Extragonadal teratoma; Fallopian tube; Parasitic