title: CT and MR findings of a retrorectal cystic hamartoma confused with an adnexal mass on ultrasound.
abstract: We describe the imaging features of a tailgut cyst mistaken for an adnexal mass. A pelvic ultrasound in a 28-year-old woman showed a 10-cm hypoechoic left pelvic mass. Having not seen the left ovary, the radiologist concluded that the mass was an endometrioma. CT disclosed a retrorectal cystic lesion with wall calcifications and internal septa. MR confirmed the extra-ovarian location of the tumor, which was hyperintense on T2-weighted images and had an intermediate signal on T1-weighted images. Surgery revealed a retrorectal cystic hamartoma. Radiological diagnosis of a tailgut cyst requires first correct localization of the tumor and then differentiation from other retrorectal masses.
authors.affiliation: Department of Radiology, Hôtel Dieu de France, Boulevard Alfred Naccache, Achrafieh, Beirut, Lebanon.
authors.forename: L
authors.initials: L
authors.lastname: Menassa-Moussa
authors.forename: H
authors.initials: H
authors.lastname: Kanso
authors.forename: A
authors.initials: A
authors.lastname: Checrallah
authors.forename: J
authors.initials: J
authors.lastname: Abboud
authors.forename: M
authors.initials: M
authors.lastname: Ghossain
mesh_terms: D000291:Adnexal Diseases / Q000000981:diagnostic imaging; D000328:Adult; D003937:Diagnosis, Differential; D005260:Female; D006222:Hamartoma / Q000175:diagnosis* / Q000601:surgery; D006801:Humans; D008279:Magnetic Resonance Imaging; D012002:Rectal Diseases / Q000175:diagnosis* / Q000601:surgery; D014057:Tomography, X-Ray Computed; D014463:Ultrasonography