title: Fine needle aspiration diagnosis of extracranial glioblastoma multiforme: Case report and review of the literature.
abstract: BACKGROUND
  Hitherto uncommon, the incidence of extracranial metastases of primary brain malignancies may increase, with improved treatment methods and longer patient survival. Fine needle aspiration biopsy is a simple, safe and reliable method to diagnose metastatic malignancy. It has definite advantages over tissue biopsy, which is more invasive and is of higher risk to the patient. Ours is a case of glioblastoma multiforme, which metastasized to the scalp and was diagnosed on fine needle aspiration biopsy. Only a few articles document the cytological features of extracranial glioblastoma multiforme, diagnosed by fine needle aspiration biopsy.
  
  
  METHODS
  We report the case of an elderly female who presented with focal neurological symptoms. She was diagnosed radiologically with an intracranial lesion in the left temporal region, which was subsequently resected. Histology revealed a glioblastoma multiforme confirmed by immunohistochemistry. The tumor recurred subsequently and the patient was treated with chemotherapy, intraoperatively. At a later stage, she presented with a scalp mass on which fine needle aspiration biopsy was performed. The cytomorphological features aided by immunohistochemistry supported a diagnosis of metastatic glioblastoma multiforme. The mass was later resected and histology confirmed the fine needle aspiration diagnosis of glioblastoma multiforme.
  
  
  CONCLUSIONS
  Reports of extracranial metastases of primary brain tumors are few. When they do occur, the primary cause is implantation during surgery or biopsy. However, spontaneous metastases to other organs do occur rarely. We believe fine needle aspiration biopsy to be very useful in the diagnosis of metastatic glioblastoma multiforme. The ability to use a cellblock for immunohistochemical studies is greatly advantageous and helpful in differentiating this tumor, from other malignancies that can occur in the scalp. A detailed discussion of the material obtained from fine needle aspiration biopsy of metastatic glioblastoma multiforme is presented, as well as a review of previous accounts in the literature.
authors.affiliation: Department of Pathology, USC/Keck School of Medicine, Los Angeles, USA. schultz@usc.edu
authors.forename: Stacey
authors.initials: S
authors.lastname: Schultz
authors.forename: Gregory S
authors.initials: GS
authors.lastname: Pinsky
authors.forename: Nancy C
authors.initials: NC
authors.lastname: Wu
authors.forename: Marc C
authors.initials: MC
authors.lastname: Chamberlain
authors.forename: A Sonali
authors.initials: AS
authors.lastname: Rodrigo
authors.forename: Sue E
authors.initials: SE
authors.lastname: Martin