Craniocervical neuroepithelial cyst (colloid cyst).
D000293:Adolescent; D002526:Cerebellar Diseases / Q000000981:diagnostic imaging*; D002530:Cerebellopontine Angle / Q000000981:diagnostic imaging; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D003388:Cranial Fossa, Posterior; D003560:Cysts / Q000000981:diagnostic imaging*; D005260:Female; D005539:Foramen Magnum / Q000000981:diagnostic imaging*; D006801:Humans; D006849:Hydrocephalus / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed