title: Delayed intracranial and bony metastasis of paraganglioma.
abstract: BACKGROUND
  Paragangliomas are tumors of neural crest origin that arise from the extra-adrenal paraganglia. In contrast with the often quoted 10% rule of malignancy for pheochromocytomas, the rate of malignancy as defined by local invasion or distant metastasis has been reported to be from 20% to as high as 50% in some case series with the most common sites of distant metastases being the liver, lungs, and bones. Here we present the case of a patient who presented with a rare case of intracranial metastasis from abdominal paraganglioma.
  
  
  METHODS
  Our patient was a 48-year-old male with a distant history of multiple resections of abdominal paraganglioma in 1975 who presented with left shoulder, and left occipital metastasis 35 years after his original paraganglioma operations.
  
  
  CONCLUSIONS
  Intracranial metastasis of paraganglioma is rare. There are unfortunately no known criteria to assess the risk of metastatic potential and given the long possible latency period between the resection of the primary tumor and the discovery of metastatic disease, patients with paragangliomas require lifelong monitoring. The optimal interval of monitoring has not been elucidated but follow-up every 5-10 years seems warranted.
authors.affiliation: Department of Neurological Surgery, University of California Los Angeles, Los Angeles, CA, USA.
authors.forename: Andrew
authors.initials: A
authors.lastname: Yew
authors.forename: Won
authors.initials: W
authors.lastname: Kim
authors.forename: Sue
authors.initials: S
authors.lastname: Chang
authors.forename: Isaac
authors.initials: I
authors.lastname: Yang