title: Cystic meningiomas.
abstract: BACKGROUND
  Meningiomas are generally solid tumors and are easily diagnosed by CT scans and MRI scans. Rarely are these tumors associated with cysts that can cause a confusion in the pre- and intraoperative diagnosis. Cysts associated with meningiomas may be intratumoral or peritumoral.
  
  
  METHODS
  The authors conducted a retrospective study of the seventeen meningiomas, out of a total number of 232, which were associated with cysts. The cysts were classified based on their relationship to the tumor. The patients' sex, age group, location of the tumor, and pathological type of tumor were also analyzed.
  
  
  RESULTS
  The 17 cases of cystic meningioma formed 7.3% of the meningiomas seen between 1984 and 1993. Eleven of these were intratumoral and 6 peritumoral. One case had both intra- and peritumoral cysts. The tumors were found mostly in the fourth and fifth decades of life. Histologically, all the peritumoral cysts except one were associated with meningotheliomatous meningiomas. Tumors with peritumoral cysts were more common in males. Intratumoral cysts, more common in females, were angioblastic or meningotheliomatous on histopathology. Only one case was an anaplastic meningioma.
  
  
  CONCLUSIONS
  Cysts associated with meningiomas, although uncommon, are certainly not rare. The peritumoral and the intratumoral cysts form distinct subtypes needing separate consideration. Cystic meningiomas are only rarely malignant.
authors.affiliation: A. Lakshmipathi Neurosurgical Centre, Voluntary Health Services Medical Centre, Madras, India.
authors.forename: K
authors.initials: K
authors.lastname: Sridhar
authors.forename: R
authors.initials: R
authors.lastname: Ravi
authors.forename: B
authors.initials: B
authors.lastname: Ramamurthi
authors.forename: M C
authors.initials: MC
authors.lastname: Vasudevan
mesh_terms: D000328:Adult; D003560:Cysts; D005260:Female; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008577:Meningeal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology*; D008579:Meningioma / Q000000981:diagnostic imaging / Q000473:pathology*; D008875:Middle Aged; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed