title: Castleman's disease in the pelvic retroperitoneum: A case report and review of the Japanese literature.
abstract: BACKGROUND
  Castleman's disease is a fairly rare benign tumor of lymphoid origin. It can develop anywhere lymphoid tissue is found, but the expected origin is mediastinum and rarely pelvic retroperitoneum.
  
  
  METHODS
  A 22-year-old woman was admitted to our hospital for a mass in the pelvic retroperitoneum that was detected incidentally on an ultrasonography during a routine medical checkup with no signs of symptoms. After laboratory examination, ultrasonography, and magnetic resonance imaging (MRI), surgical resection was performed successfully through a lower midline incision. But the patient was needed transfusion because of massive bleeding. Postoperative histopathological diagnosis was hyaline-vascular type of Castleman's disease. The patient is leading an active social life without any signs of sequelae or recurrence.
  
  
  CONCLUSIONS
  Through the review of Japanese literature on Castleman's disease in the retroperitoneum, the characteristics of preoperative imaging findings are studied. Castleman's disease is easily misdiagnosed clinically because of its scarcity and no specific imaging findings. And the embolization via angiography should be considered in the hypervasular tumors such as in this case to prevent massive bleeding and transfusion.
  
  
  CONCLUSIONS
  Although Castleman's disease is uncommon, it should always be included in the differential diagnosis of pelvic retroperitoneal tumors. A better knowledge of this disease would help surgeon to avoid unnecessarily extensive resection and massive bleeding for transfusion when dealing with retroperitoneal tumors.
authors.affiliation: Department of Gastroenterological Surgery, Toyota Memorial Hospital, 1-1, Heiwa-cho, Toyota, Aichi 471-8513, Japan. Electronic address: rio-321@coda.ocn.ne.jp.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Sato