title: Cerebellopontine angle primitive neuroectodermal tumor mimicking trigeminal schwannoma.
abstract: BACKGROUND
  Primitive neuroectodermal tumors (PNETs) comprise a group of aggressive, poorly differentiated embryonal tumors occurring in central nervous system as well as in peripheral locations. Primary cerebellopontine angle (CPA) PNET is an extremely rare entity. It is important to have knowledge of this pathology and to be able to differentiate it from other commonly occurring CPA tumors, such as vestibular and trigeminal schwannomas. This distinction is essential because of the difference in the overall treatment plan and prognosis.
  
  
  METHODS
  This report describes a case of a young male presenting with diplopia and numbness of face; magnetic resonance imaging showed a CPA mass. With a provisional diagnosis of trigeminal schwannoma, the patient underwent surgery. Histopathology provided a diagnosis of PNET.
  
  
  CONCLUSIONS
  We discuss the importance of recognizing this rare condition and how this entity differs from the commonly occurring tumors.
authors: Department of Neurosurgery, Aga Khan University Hospital, Karachi, Pakistan.
authors: Saad Akhtar
authors: SA
authors: Khan
authors: Department of Neurosurgery, Aga Khan University Hospital, Karachi, Pakistan.
authors: Badar Uddin
authors: BU
authors: Ujjan
authors: Dow Medical College, Dow University of Health Sciences, Karachi, Pakistan.
authors: Adnan
authors: A
authors: Salim
authors: Department of Neurosurgery, Aga Khan University Hospital, Karachi, Pakistan.
authors: Shahzad
authors: S
authors: Shamim
keywords: Cerebellopontine angle; primitive neuroectodermal tumor; schwannoma; trigeminal; vestibular