title: An unusual location and presentation of a usual pathology-Colloid cyst of fourth ventricle presenting as spontaneous rhinorrhea.
abstract: Colloid cysts are relatively rare benign intracranial lesions preferentially located within the third ventricle. There are only a few reports in which they have been found to be ectopic, such as in the fourth ventricle. A young female presented on with spontaneous non-traumatic cerebrospinal fluid (CSF) rhinorrhoea for three months which was positional in nature, relieved temporarily by neck flexion. Magnetic resonance imaging (MRI) scan showed a focal well-defined rounded cystic lesion along the fourth ventricle, showing subtle peripheral rim enhancement. Significant hydrocephalus was also noted. A suboccipital craniotomy and total excision of the lesion was done. Postoperatively, the patient recovered quickly with no neurological deficits. Her rhinorrhoea was completely cured. Histopathology was consistent with a colloid cyst. Colloid cyst is rarely found in infratentorial location. However, such a rare diagnosis has to be considered in the differential diagnosis in patients who present with an infratentorial cystic lesion associated with spontaneous CSF rhinorrhoea.
authors.affiliation: Department of Radiology, Jinnah Postgraduate Medical Centre, Karachi.
authors.forename: Shumaila
authors.initials: S
authors.lastname: Arooj
authors.affiliation: Department of Radiology, Jinnah Postgraduate Medical Centre, Karachi.
authors.forename: Samar
authors.initials: S
authors.lastname: Hamid
authors.affiliation: Department of Radiology, Jinnah Postgraduate Medical Centre, Karachi.
authors.forename: Tariq
authors.initials: T
authors.lastname: Mehmood
mesh_terms: D000328:Adult; D002559:Cerebrospinal Fluid Rhinorrhea / Q000209:etiology*; D056364:Colloid Cysts / Q000150:complications / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D003399:Craniotomy / Q000379:methods*; D005260:Female; D020546:Fourth Ventricle / Q000000981:diagnostic imaging*; D006801:Humans; D006849:Hydrocephalus / Q000209:etiology*; D008279:Magnetic Resonance Imaging / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods; D016896:Treatment Outcome
keywords: Colloid cyst, Fourth ventricle cyst, Infratentorialcyst.