title: Soft-tissue perineurioma of the retroperitoneum in a 63-year-old man, computed tomography and magnetic resonance imaging findings: a case report.
abstract: BACKGROUND
  Soft-tissue perineuriomas are rare benign peripheral nerve sheath tumors in the subcutis of the extremities and the trunks of young patients. To our knowledge, this the first presentation of the computed tomography and magnetic resonance imaging of a soft-tissue perineurioma in the retroperitoneum with pathologic correlation.
  
  
  METHODS
  A 63-year-old Japanese man was referred for assessment of high blood pressure. Abdominal computed tomography and magnetic resonance imaging showed a well-defined, gradually enhancing tumor without focal degeneration or hemorrhage adjacent to the pancreatic body. Tumor excision with distal pancreatectomy and splenectomy was performed, as a malignant tumor of pancreatic origin could not be ruled out. No recurrence has been noted in the 16 months since the operation. Pathologic examination of the tumor revealed a soft-tissue perineurioma of the retroperitoneum.
  
  
  CONCLUSIONS
  Although the definitive diagnosis of soft-tissue perineurioma requires biopsy and immunohistochemical reactivity evaluation, the computed tomography and magnetic resonance imaging findings described in this report suggest inclusion of this rare tumor in the differential diagnosis when such findings occur in the retroperitoneum.
authors.affiliation: Departments of Radiology, Saitama Red Cross Hospital, 8-3-33, Kamiochiai, Chuo-ku, Saitama, Saitama, Japan. mayumihoo@gmail.com.
authors.forename: Mayumi
authors.initials: M
authors.lastname: Yasumoto
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Katada
authors.forename: Reiko
authors.initials: R
authors.lastname: Matsumoto
authors.forename: Akiko
authors.initials: A
authors.lastname: Adachi
authors.forename: Koh
authors.initials: K
authors.lastname: Kaneko