title: Perineural Spread of Renal Cell Carcinoma: A Case Illustration with a Proposed Anatomic Mechanism and a Review of the Literature.
abstract: BACKGROUND
  Perineural spread (PNS) is an unusual mechanism of tumor extension and has been typically reported in squamous cell carcinoma, adenocystic carcinoma, and desmoplastic melanoma. Our group has previously demonstrated PNS in rectal, prostate, bladder, and cervical cancer from the primary site along the autonomic nerves to the major somatic nerves and even intradurally. We believe similar principles apply to renal cell carcinoma (RCC) as well, despite the different anatomy.
  
  
  METHODS
  We performed a retrospective search to identify cases of intradural-extramedullary metastases of RCC caused by PNS. Strict anatomic and imaging inclusion criteria were defined: only lesions located between T6 and L3 were included, and PNS as a potential cause had to be supported by imaging evidence. Although 3 cases of spinal intradural metastases were identified, only one met our strict inclusion criteria. A 61-year-old woman developed a late intradural-extramedullary metastasis of RCC 16 years after the original diagnosis that we believe represents an example of visceral organ PNS.
  
  
  CONCLUSIONS
  RCC can propagate via PNS from the primary tumor along the autonomic nerves to the aorticorenal, celiac, and mesenteric ganglia and then along the thoracic and lumbar splanchnic nerves to the corresponding spinal nerves and intradurally. We present radiologic evidence together with the review of the literature to support the premise that PNS of RCC not only occurs but goes unrecognized.
authors: Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota, USA; International Clinical Research Center, St. Anne's University Hospital Brno, Brno, Czech Republic.
authors: Stepan
authors: S
authors: Capek
authors: Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota, USA.
authors: William E
authors: WE
authors: Krauss
authors: Department of Radiology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Kimberly K
authors: KK
authors: Amrami
authors: Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, Minnesota, USA; Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA.
authors: Joseph E
authors: JE
authors: Parisi
authors: Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota, USA. Electronic address: spinner.robert@mayo.edu.
authors: Robert J
authors: RJ
authors: Spinner
mesh_terms: D002292:Carcinoma, Renal Cell / Q000150:complications* / Q000473:pathology*; D016206:Databases, Bibliographic / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007680:Kidney Neoplasms / Q000150:complications* / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D012189:Retrospective Studies; D013120:Spinal Cord Neoplasms / Q000000981:diagnostic imaging / Q000556:secondary*; D013127:Spinal Nerves / Q000000981:diagnostic imaging
keywords: Metastasis; Perineural spread; Renal cell carcinoma; Spinal