title: Well-differentiated papillary adenocarcinoma arising in a supratentorial enterogenous cyst: case report.
abstract: OBJECTIVE
  We report a case of a well-differentiated papillary adenocarcinoma arising in an supratentorial enterogenous cyst. The clinicopathological features of this case and a brief review of the literature are presented.
  
  
  METHODS
  A 45-year-old woman presented with abrupt onset of sensory seizures and abnormal sensation on the left side of her face, left leg, and left arm. Radiological studies showed a cystic extraaxial tumor with mass effect in the right parietal area. The initial clinical impression was a metastatic lesion, and a comprehensive metastatic workup revealed no evidence of tumor elsewhere.
  
  
  METHODS
  A gross total resection of the solid cystic tumor was achieved by a frontoparietal craniotomy. Sixteen months after the initial surgery, the patient presented with signs of increased intracranial pressure and a large parietal cyst. The cyst was fenestrated at the time of the second craniotomy.
  
  
  CONCLUSIONS
  A pathological study of the initial surgical material revealed it to be a well-differentiated papillary adenocarcinoma in association with an enterogenous cyst. The second surgical specimen consisted only of the benign cyst wall. The patient recovered uneventfully from the second surgery and was free of symptoms 6 months postoperatively. The importance of recognizing the rare possibility of malignant progression of a benign enterogenous cyst in the central nervous system is discussed.
authors.affiliation: Department of Pathology, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA.
authors.forename: L C
authors.initials: LC
authors.lastname: Ho
authors.forename: A
authors.initials: A
authors.lastname: Olivi
authors.forename: C H
authors.initials: CH
authors.lastname: Cho
authors.forename: P C
authors.initials: PC
authors.lastname: Burger
authors.forename: F
authors.initials: F
authors.lastname: Simeone
authors.forename: T
authors.initials: T
authors.lastname: Tihan
mesh_terms: D000231:Adenocarcinoma, Papillary / Q000175:diagnosis / Q000209:etiology / Q000473:pathology* / Q000601:surgery; D001932:Brain Neoplasms / Q000175:diagnosis / Q000209:etiology / Q000473:pathology* / Q000556:secondary / Q000601:surgery; D002471:Cell Transformation, Neoplastic; D016545:Choroid Plexus Neoplasms / Q000175:diagnosis; D003560:Cysts / Q000473:pathology*; D003937:Diagnosis, Differential; D018450:Disease Progression; D004828:Epilepsies, Partial / Q000209:etiology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009382:Neoplasms, Unknown Primary / Q000175:diagnosis; D009436:Neural Tube Defects / Q000473:pathology* / Q000601:surgery; D010296:Parietal Lobe / Q000473:pathology* / Q000601:surgery; D012678:Sensation Disorders / Q000209:etiology