title: CT finding of ectopic pituitary adenoma: Case report and review of literature.
abstract: BACKGROUND
  Ectopic pituitary adenoma was first described by Erdheim in 1909, about 100 cases have been reported in literature, to the best of our knowledge, an ectopic pituitary adenoma located in the parapharyngeal space has not been reported thus far.
  
  
  METHODS
  A 59-year-old woman presenting with a neck lump, which was painlessness and growing, was without any neurological disorders or endocrine disorders. Auxiliary examinations included ultrasound, electronic nasopharyngolaryngoscopy, endocrine assessment, CT, and CT angiography.
  
  
  RESULTS
  A CT scan showed a soft tissue density mass with clear boundary involving the carotid sheath area. The contrast-enhanced CT scan showed heterogeneous density. Tissues around the mass were pushed and displaced. CT angiography showed the mass was hypervascular and supported by the right internal carotid artery and branches of the external carotid artery. The tumor underwent a total removal and was confirmed as an adenoma with pituitary cells by histopathologic examinations, and postoperative recovery went well.
  
  
  CONCLUSIONS
  It is rarely seen that a pituitary adenoma is ectopic to the parapharyngeal space. Diagnosis is difficult and mainly depends on the postoperative pathological examination.
authors.affiliation: Department of Radiology, the First Affiliated Hospital, Chongqing Medical University, Chongqing, China.
authors.forename: Xiaofeng
authors.initials: X
authors.lastname: Wu
authors.affiliation: Department of Radiology, the First Affiliated Hospital, Chongqing Medical University, Chongqing, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Wen
mesh_terms: D000236:Adenoma; D000792:Angiography; D002828:Choristoma / Q000000981:diagnostic imaging* / Q000473:pathology; D005260:Female; D006801:Humans; D008875:Middle Aged; D010608:Pharyngeal Diseases / Q000000981:diagnostic imaging* / Q000473:pathology; D010911:Pituitary Neoplasms; D014057:Tomography, X-Ray Computed
keywords: CT; adenoma; ectopic; parapharyngeal space; pituitary gland