title: Arachnoid cyst with extraordinary extracranial extension in the skull base as a result of an iatrogenic defect of the middle cranial fossa floor: case report and literature review.
abstract: Arachnoid cysts are benign intracranial lesions that are typically diagnosed incidentally. They are divided into two types: congenital and acquired. Acquired arachnoid cysts are rare and usually arise after trauma, infection, or haemorrhage. In this report, a rare case of an iatrogenic multiloculated arachnoid cyst as an unusual complication of a skull base defect is presented. It extended extracranially into the sphenoid sinus, the ethmoid, the infratemporal fossa, the nasopharynx and the nasal cavity, as well as into the pterygomaxillary and retromaxillary space, appearing with a distinct clinical picture. We discuss the differential diagnosis and the potential causes of the lesion and provide a brief review of the literature.
authors.affiliation: Department of Otorhinolaryngology, University Hospital, School of Medicine, Langenbeckstr 1, 55101 Mainz, Germany.
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Koutsimpelas
authors.forename: Wibke
authors.initials: W
authors.lastname: Mueller-Forell
authors.forename: Peter
authors.initials: P
authors.lastname: Stoeter
authors.forename: Otto
authors.initials: O
authors.lastname: Hey
authors.forename: Wolf J
authors.initials: WJ
authors.lastname: Mann
mesh_terms: D000328:Adult; D018322:Angiofibroma / Q000601:surgery*; D016080:Arachnoid Cysts / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D035301:Cranial Fossa, Middle; D003399:Craniotomy / Q000009:adverse effects*; D004388:Dura Mater / Q000473:pathology / Q000601:surgery; D006801:Humans; D007049:Iatrogenic Disease; D008279:Magnetic Resonance Imaging; D008297:Male; D009078:Mucocele / Q000601:surgery; D009296:Nasal Cavity / Q000000981:diagnostic imaging; D009303:Nasopharyngeal Neoplasms / Q000601:surgery*; D009305:Nasopharynx / Q000000981:diagnostic imaging; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D011859:Radiography; D019291:Skull Base / Q000473:pathology* / Q000601:surgery; D013101:Sphenoid Sinus / Q000000981:diagnostic imaging