title: Dumbbell-shaped nonpsammomatous malignant melanotic schwannoma of the cervical spinal root.
abstract: BACKGROUND
  Melanotic schwannoma is a very rare tumor of Schwann cell origin, which can develop in various locations, similar to conventional schwannoma. This tumor has a malignant potential and therefore careful therapy is required.
  
  
  OBJECTIVE
  To describe a case of melanotic schwannoma with a histopathologically and clinically malignant behavior.
  
  
  METHODS
  Case report.
  
  
  METHODS
  A 64-year-old man presented with sensory changes in his arm and gait disturbance. Magnetic resonance imaging revealed a dumbbell-shaped tumor at the left C7 spinal root, which was hyperintense on T1-weighted images and generally hypointense on T2-weighted images in comparison with conventional schwannoma; however, the peripheral zone was relatively hyperintense, and the central zone was hypointense like a target sign.
  
  
  RESULTS
  The tumor was partially resected and diagnosed to be nonpsammomatous malignant melanotic schwannoma. The patient experienced local recurrence and metastases to the bone and lung and finally developed quadriplegia. Radiation therapy failed to palliate the symptoms.
  
  
  CONCLUSIONS
  Some melanotic schwannomas present with an aggressive behavior, which thus leads to poor prognosis. We should therefore be familiar with its characteristic clinical imaging and pathologic findings to provide a correct diagnosis and appropriate treatment for such patients.
authors.affiliation: Department of Radiology, Chiba University Hospital, 1-8-1 Inohana, Chuo-ku, Chiba 260-8677, Japan. yokotaha@gmail.com
authors.forename: Hajime
authors.initials: H
authors.lastname: Yokota
authors.forename: Koichi
authors.initials: K
authors.lastname: Isobe
authors.forename: Masazumi
authors.initials: M
authors.lastname: Murakami
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Kubosawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Uno
mesh_terms: D001859:Bone Neoplasms / Q000150:complications / Q000532:radiotherapy / Q000556:secondary; D003131:Combined Modality Therapy; D003937:Diagnosis, Differential; D017809:Fatal Outcome; D006801:Humans; D008297:Male; D008579:Meningioma / Q000175:diagnosis*; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D009442:Neurilemmoma / Q000175:diagnosis* / Q000556:secondary / Q000628:therapy; D010166:Palliative Care; D011782:Quadriplegia / Q000209:etiology; D013120:Spinal Cord Neoplasms / Q000175:diagnosis* / Q000628:therapy; D013126:Spinal Nerve Roots / Q000473:pathology*