title: Petrosquamosal sinus discovered during mastoidectomy, and its radiologic appearance on temporal bone CT: case report and brief review.
abstract: We report the case of a 47-year-old woman who underwent a mastoidectomy. Preoperative computed tomography demonstrated an unusually distended bony canal that passed through the superolateral portion of the right petrous bone. Intraoperatively, we identified the anomaly as a petrosquamosal sinus (PSS). This unusually dilated venous channel had arisen from the adjacent sigmoid sinus. A PSS is an emissary vein of the posterior fossa that courses along the petrosquamosal junction, connecting the sigmoid or transverse sinus with the extracranial venous system. While it usually regresses during fetal life, a dilated PSS occasionally persists into adulthood. Its anatomic course may lead to problematic bleeding during mastoidectomy.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Eulji University School of Medicine, Hagye 1 dong 280-1, Nowongu, Seoul, Republic of Korea.
authors.forename: Hyun Joon
authors.initials: HJ
authors.lastname: Shim
authors.forename: Seong Jun
authors.initials: SJ
authors.lastname: Song
authors.forename: Ki Woong
authors.initials: KW
authors.lastname: Chung
authors.forename: Sang Won
authors.initials: SW
authors.lastname: Yoon
mesh_terms: D003392:Cranial Sinuses / Q000002:abnormalities* / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008416:Mastoid / Q000601:surgery; D008875:Middle Aged; D010579:Petrous Bone / Q000002:abnormalities / Q000000981:diagnostic imaging*; D013701:Temporal Bone / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed