Special problems encountering surgical management of large retroperitoneal schwannomas.

Background: Retroperitoneal schwannomas are rare, usually benign tumors that originate in the neural sheath and account for only a small percentage of retroperitoneal tumors. The aim of this clinical study is to present our experience in managing retroperitoneal schwannomas with a review of the current literature and to point out the surgical technical difficulties we faced, due to the tumor's strange behavior that eroded the vertebra in two cases without causing malignant invasion.

Methods: We reviewed the medical files of 69 patients treated in our department for retroperitoneal tumors from January 1991 until December 2006. Five patients had retroperitoneal schwannomas according to pathology report.

Results: There were two male and three female patients, with a mean age of 56 years (range 44-67 years). All patients were asymptomatic and none suffered from von Recklinghausen disease. Imaging workup included ultrasonography, computed tomography and magnetic resonance imaging. One patient, after having a non-diagnostic computed tomography fine needle aspiration (CT-FNA), underwent exploratory laparotomy and incisional biopsy that established the diagnosis of schwannoma. After complete excision of the tumors, postoperative course was uneventful in all patients. Tumors' maximum diameter was 12.7 cm (range 7-20 cm). No recurrences were detected during the follow up period (6-75 months).

Conclusion: Preoperative establishment of diagnosis is difficult in case of retroperitoneal schwannomas, however close relationship of retroperitoneal tumors with adjacent neural structures in imaging studies should raise a suspicion. Complete surgical resection is the treatment of choice. Histology and Immunohistochemistry confirms the diagnosis.